TERASOLUNA Batch Framework for Java (5.x) Development Guideline - version 5.0.1.RELEASE, 2017-9-27
> INDEX

Overview

This chapter describes how to input and output files.

The usage method of this function is same in the chunk model as well as tasklet model.

Type of File which can be handled

Type of File which can be handled

The type of files that can be handled with TERASOLUNA Batch 5.x are ones decribed as below.
This is the same for which Spring Batch can handle.

  • Flat File

  • XML

Here it will explain how to handle flat file first, and then explain about XML in How To Extend.

First, show the types of Flat File which can be used with TERASOLUNA Batch 5.x.
Each row inside the flat file will be called record, and type of file is determined by the record’s format.

Record Format
Format Overview

Variable-length Record

A record format which each items are separated by a delimiter, such as CSV and TSF. Each item’s length can be variable.

Fixed-length Record

A record format which each items are separeted by the items length(bytes). Each item’s length are fixed.

Single String Record

1 Record will be handled as 1 String item.
File Structure which can be handled

The basic structure for Flat File is constructed by these 2 points.

  • Record Division

  • Record Format

Elements to construct format of Flat File
Element Overview

Record Division

A division will indicate the type of record, such as Header Record, Data Record, and Trailer Record.
Details will be described later.

Record Format

The format will have informations of the record such as how many rows there is for Header, Data, and Trailer, how many times eace record will repeat, and so on.
There is also Single Format and Multi Format.Details will be described later.

With TERASOLUNA Batch 5.x, Flat File with Single Format of Multi Format which includes each record division can be handles.

Here it willl explain about the record division and the record formats.

The overview of each record devision is explained as below.

Characteristic of each Record Division
Record Division Overview

Header Record

A record that is mentioned at the beginning of the file(data part).
It has items such as field names, common matters of the file, and summary of the data part.

Data Record

It is a record having data to be processed as a main object of the file.

Trailer/Footer Record

A record that is mentioned at the end of the file if the file(data part).
It has items such as common matters of the file and summary of the data part.
For Single Format file, it is called a Fotter Record.

Footer/End Record

A record that is mentioned at the end of the file if the file is a Multi Format.
It has items such as common matters of the file and summary of the data part.
About the field that indicates the record division

A flat file having a header record or a trailer record may have a field indicating a record division.
In TERASOLUNA Batch 5.x, especially in the processing of multi-format files, the record division field is utilized, for example when different processing is performed for each record division.
Refer to Multi format for the implementation when selecting the processing to be executed by record classification.
About the name of file format

Depending on the definition of the file format in each system, There are cases where names are different from this guideline such as calling Footer Record as End Record.
Must be read as appropriate.

A summary of Single Format and Multi Format is shown below.

Overview of Single Format and Multi Format
Format Overview

Single Format

A format with Header N Rows + Data N Rows + Trailer N Rows.

Multi Format

A format with (Header N Rows + Data N Rows + Trailer N Rows) * N + Footer N Rows.
A format in which a Footer Record is added after repeating a Single Format a plurality of times.

The Multi Format record structure is shown in the figure as follows.

Multi format file layout
Multi Format Rrecord Structure Diagram

An example of a Single Format and Multi Format flat file is shown below.
// is used as a comment-out character for the description of the file.

Example of Single Format, flat file(CSV format) without record division
branchId,year,month,customerId,amount  // (1)
000001,2016,1,0000000001,100000000  // (2)
000001,2016,1,0000000002,200000000  // (2)
000001,2016,1,0000000003,300000000  // (2)
000001,3,600000000  // (3)
Item list of file contents
No Descriptions

(1)

A header record
Field name of the data part is described.

(2)

A data record.

(3)

A trailer record.
It holds summary information of the data part.
Example of Multi Format, flat file(CSV format) with record division
// (1)
H,branchId,year,month,customerId,amount  // (2)
D,000001,2016,1,0000000001,100000000
D,000001,2016,1,0000000002,200000000
D,000001,2016,1,0000000003,300000000
T,000001,3,600000000
H,branchId,year,month,customerId,amount  // (2)
D,00002,2016,1,0000000004,400000000
D,00002,2016,1,0000000005,500000000
D,00002,2016,1,0000000006,600000000
T,00002,3,1500000000
H,branchId,year,month,customerId,amount  // (2)
D,00003,2016,1,0000000007,700000000
D,00003,2016,1,0000000008,800000000
D,00003,2016,1,0000000009,900000000
T,00003,3,2400000000
F,3,9,4500000000  // (3)
Item list of file contents
No Descriptions

(1)

It has a field indicating the record division at the beginning of the record.
Each record division is defined as below.
H：Header Record
D：Data Record
T：Trailer Record
F：Footer Record

(2)

Every time branchId changes, it repeats header, data, trailer.

(3)

A footer record.
It holds summary information for the whole file.
Assumptions on format of data part

In How To Use, it will explain on the premise that the layout of the data part is the same format.
This means that all the records of the data part are mapped to the same conversion target class
About explanation of Multi Format file

  • In How To Use, it will describe about the Single Format file.

  • For flat files having Multi Format or a structure including a footer part in the above structure, refer to How To Extend

A component that inputs and outputs a flat file

Describe a class for handling flat file.

Input

The relationships of classes used for inputting flat files are as follows.

Component relationship FlatFileItemReader class diagram
Relationship of classes used for inputting flat files

The calling relationship of each component is as follows.

Component relationship FlatFileItemReader sequence diagram
Calling relationship of each component

Details of each component are shown below.

org.springframework.batch.item.file.FlatFileItemReader

Implementation class of ItemReader to use for loading flat files. Use the following components.
The flow of simple processing is as follows.
1.Use BufferedReaderFactory to get BufferedReader.
2.Read one record from the flat file using the acquired BufferedReader.
3.Use LineMapper to map one record to the target bean.

org.springframework.batch.item.file.BufferedReaderFactory

Generate BufferedReader to read the file.

org.springframework.batch.item.file.LineMapper

One record is mapped to the target bean. Use the following components.
The flow of simple processing is as follows.
1.Use LineTokenizer to split one record into each item.
2.Mapping items split by FieldSetMapper to bean properties.

org.springframework.batch.item.file.transform.LineTokenizer

Divide one record acquired from the file into each item.
Each partitioned item is stored in FieldSet class.

org.springframework.batch.item.file.mapping.FieldSetMapper

Map each item in one divided record to the property of the target bean.

Output

Relationships of classes used for outputting flat files are as follows.

Component relationship FlatFileItemWriter class diagram
Relationship of classes used for outputting flat files

The calling relationship of each component is as follows.

Component relationship FlatFileItemWriter sequence diagram
Calling relationship of each component
org.springframework.batch.item.file.FlatFileItemWriter

Implementation class of ItemWriter for exporting to a flat file. Use the following components. LineAggregator Mapping the target bean to one record.

org.springframework.batch.item.file.transform.LineAggregator

It is used to map the target bean to one record. The mapping between the properties of the bean and each item in the record is done in FieldExtractor.

org.springframework.batch.item.file.transform.FieldExtractor

Map the property of the target bean to each item in one record.

How To Use

Descriptoins for how to use flat file according to the record format.

Then, the following items are explained.

Variable-length record

Describe the definition method when dealing with variable-length record file.

Input

An example of setting for reading the following input file is shown.

Input File Sample
000001,2016,1,0000000001,1000000000
000002,2017,2,0000000002,2000000000
000003,2018,3,0000000003,3000000000
Class to be converted
public class SalesPlanDetail {

    private String branchId;
    private int year;
    private int month;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}

The setting for reading the above file is as follows.

Bean definition example
<!-- (1) (2) (3) -->
<bean id="reader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:resource="file:#{jobParameters['inputFile']}"
      p:encoding="MS932"
      p:strict="true">
  <property name="lineMapper">  <!-- (4) -->
    <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
      <property name="lineTokenizer">  <!-- (5) -->
        <!-- (6) (7) (8) -->
        <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
              p:names="branchId,year,month,customerId,amount"
              p:delimiter=","
              p:quoteCharacter='"'/>
      </property>
      <property name="fieldSetMapper">  <!-- (9) -->
        <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
              p:targetType="org.terasoluna.batch.functionaltest.app.model.plan.SalesPlanDetail"/>
      </property>
    </bean>
  </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set the input file.

Nothing

(2)

encoding

Sets the character code of the input file.
Default value of the character code of the component offered by Spring Batch varies for ItemReader and ItemWriter (Default value of ItemWriter is "UTF-8").
Hence, it is recommended to explicitly set character code even while using default value.

JavaVM’s default character set

(3)

strict

If true is set, an exception occurs if the input file does not exist(can not be opened).

true

(4)

lineMapper

Set org.springframework.batch.item.file.mapping.DefaultLineMapper.
DefaultLineMapper is LineMapper which provides the basic operation of converting records to the class to be converted using the defined LineTokenizer and FieldSetMapper.

Nothing

(5)

lineTokenizer

Set org.springframework.batch.item.file.transform.DelimitedLineTokenizer.
DelimitedLineTokenizer is an implementation class of LineTokenizer that separates records by specifying delimiters.
It corresponds to the reading of escaped line feeds, delimiters, and enclosed characters defined in the specification of RFC-4180, which is a general format of CSV format.

Nothing

(6)

names

Give a name to each item of one record.
Each item can be retrieved using the name set in FieldSet used in FieldSetMapper.
Set each name from the beginning of the record with a comma separator.
When using BeanWrapperFieldSetMapper it is mandatory setting.

Nothing

(7)

delimiter

Set delimiter

comma

(8)

quoteCharacter

Set enclosing character

Nothing

(9)

fieldSetMapper

If special conversion processing such as character strings and numbers is unnecessary, use org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper, and specify the class to be converted to property targetType. By doing this, an instance that automatically sets the value in the field that matches the name of each item set in (5) will be created.
If conversion processing is necessary, set the implementation class of org.springframework.batch.item.file.mapping.FieldSetMapper.

Nothing

See How To Extend for the case of implementing FieldSetMapper yourself.
How to enter TSV format file

When reading the TSV file, it can be realized by setting a tab as a delimiter.

TSV file loading: Example of delimiter setting (setting by constant)
<property name="delimiter">
    <util:constant
            static-field="org.springframework.batch.item.file.transform.DelimitedLineTokenizer.DELIMITER_TAB"/>
</property>

Or, it may be as follows.

TSV file reading: Example of delimiter setting (setting by character reference)
<property name="delimiter" value="&#09;"/>

Output

An example of setting for writing the following output file is shown.

Output file example
001,CustomerName001,CustomerAddress001,11111111111,001
002,CustomerName002,CustomerAddress002,11111111111,002
003,CustomerName003,CustomerAddress003,11111111111,003
Class to be converted
public class Customer {

    private String customerId;
    private String customerName;
    private String customerAddress;
    private String customerTel;
    private String chargeBranchId;
    private Timestamp createDate;
    private Timestamp updateDate;

    // omitted getter/setter
}

The settings for writing the above file are as follows.

Bean definition example
<!-- Writer -->
<!-- (1) (2) (3) (4) (5) (6) (7) -->
<bean id="writer"
      class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
      p:resource="file:#{jobParameters['outputFile']}"
      p:encoding="MS932"
      p:lineSeparator="&#x0A;"
      p:appendAllowed="true"
      p:shouldDeleteIfExists="false"
      p:shouldDeleteIfEmpty="false"
      p:transactional="true">
  <property name="lineAggregator">  <!-- (8) -->
    <bean class="org.springframework.batch.item.file.transform.DelimitedLineAggregator"
          p:delimiter=",">  <!-- (9) -->
      <property name="fieldExtractor">  <!-- (10) -->
        <!-- (11) -->
        <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
              p:names="customerId,customerName,customerAddress,customerTel,chargeBranchId">
      </property>
    </bean>
  </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set the output file.

Nothing

(2)

encoding

Sets the character code of the output file.
Default value of character code of the components offered by Spring Batch varies for ItemReader and ItemWriter (Default value of ItemReader is "default character set of JavaVM").
Hence, it is recommended to explicitly set character code even while using default value.

UTF-8

(3)

lineSeparator

Set record break (line feed code).

line.separator of system’s property

(4)

appendAllowed

If true, add to the existing file.
If true, it must be noted that setting value of shouldDeleteIfExists is invalidated.

false

(5)

shouldDeleteIfExists

If appendAllowed is true, it is recommended not to specify property since the property is invalidated.
If true, delete if the file already exists.
If false, throw an exception if the file already exists.

true

(6)

shouldDeleteIfEmpty

If true, delete file for output when output count is 0.
Since unintended behaviour is likely to happen by combining with other properties, it is recommended not to set it to true. For details, refer Described later.

false

(7)

transactional

Set whether to perform transaction control. For details, see Transaction Control.

true

(8)

lineAggregator

Set org.springframework.batch.item.file.transform.DelimitedLineAggregator.
To enclose a field around it, set org.terasoluna.batch.item.file.transform.EnclosableDelimitedLineAggregator.
Usage of EnclosableDelimitedLineAggregator will be described later.

Nothing

(9)

delimiter

Sets the delimiter.

comma

(10)

fieldExtractor

If special conversion processing for strings and numbers is unnecessary, you can use org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor.
If conversion processing is necessary, set implementation class of org.springframework.batch.item.file.transform.FieldExtractor.
An example for implementatiion of FieldExtractor, refer to Output of Fixed-length record where a sample is described using full-width character.

Nothing

(11)

names

Give a name to each item of one record. Set each name from the beginning of the record with a comma separator.

Nothing
It is recommended not to set true for shouldDeleteIfEmpty property of FlatFileItemWriter.

For FlatFileItemWriter, unintended files are deleted when the properties are configured by the combinations as shown below.

  • p:shouldDeleteIfEmpty="true"

  • p:shouldDeleteIfExists="false"

Reasons are as given below.
When shouldDeleteIfEmpty is set to true, file for output is deleted when output count is 0.
The "output count is 0" also includes a case wherein file for output already exists with shouldDeleteIfExists set to false.

Hence, when properties are specified by combinations above, file for output is deleted if it exists already.
This becomes the unintended behaviour when preferably an exception should be thrown and the process should be terminated in case a file for output exists.

It is recommended not to set shouldDeleteIfEmpty property to true since it results in unintended operation.

Further, when subsequent processing like deletion of file is to be done if output count is 0, implementation should be done by using OS command or Listener instead of shouldDeleteIfEmpty property.
How to use EnclosableDelimitedLineAggregator

To enclose a field around it, use org.terasoluna.batch.item.file.transform.EnclosableDelimitedLineAggregator provided by TERASOLUNA Batch 5.x.
The specification of EnclosableDelimitedLineAggregator is as follows.

  • Optional specification of enclosure character and delimiter character

    • Default is the following value commonly used in CSV format

      • Enclosed character: "(double quote)

      • Separator: , (comma)

  • If the field contains a carriage return, line feed, enclosure character, or delimiter, enclose the field with an enclosing character

    • When enclosing characters are included, the enclosing character will be escaped by adding an enclosing character right before this enclosing characters.

    • All fields can be surrounded by characters by setting

The usage of EnclosableDelimitedLineAggregator is shown below.

Output file example
"001","CustomerName""001""","CustomerAddress,001","11111111111","001"
"002","CustomerName""002""","CustomerAddress,002","11111111111","002"
"003","CustomerName""003""","CustomerAddress,003","11111111111","003"
Class to be converted
// Same as above example
Bean definition example(only settings for lineAggregator)
<property name="lineAggregator">  <!-- (1) -->
  <!-- (2) (3) (4) -->
  <bean class="org.terasoluna.batch.item.file.transform.EnclosableDelimitedLineAggregator"
        p:delimiter=","
        p:enclosure='"'
        p:allEnclosing="true">
      <property name="fieldExtractor">
        <!-- omitted settings -->
      </property>
  </bean>
</property>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

lineAggregator

Set org.terasoluna.batch.item.file.transform.EnclosableDelimitedLineAggregator.

Nothing

(2)

delimiter

Sets the delimiter.

comma

(3)

enclosure

Set the enclosing character.
If the enclosing character is included in the field, it is replaced with a concatenated character as an escape process.

double quote

(4)

allEnclosing

If true, all fields are enclosed in an enclosing character.
If false, only fields containing carriage return (CR), line-leading (LF), delimiter, and enclosing characters will be enclosed.

false

TERASOLUNA Batch 5.x provides the extension class org.terasoluna.batch.item.file.transform.EnclosableDelimitedLineAggregator to satisfy the specification of RFC-4180.

The org.springframework.batch.item.file.transform.DelimitedLineAggregator provided by Spring Batch does not correspond to the enclosing process of the field, therefore it can not satisfy the specification of RFC-4180. Refer to Spring Batch/BATCH-2463 .

The format of the CSV format is defined as follows in RFC-4180 which is a general format of CSV format.

  • If the field does not contain line breaks, enclosing characters, or delimiters, each field can be enclosed in double quotes (enclosing characters) or not enclosed

  • Fields that contain line feed (CRLF), double quote (enclosing character), comma (delimiter) should be enclosed in double quotes

  • If the field is enclosed in double quotes (enclosing characters), the double quotes contained in the value of the field must be escaped with a single double quote immediately before it
How to output TSV format file

When outputting a TSV file, it can be realized by setting a tab as a delimiter.

Setting example of delimiter when outputting TSV file (setting by constant)
<property name="delimiter">
    <util:constant
            static-field="org.springframework.batch.item.file.transform.DelimitedLineTokenizer.DELIMITER_TAB"/>
</property>

Or, it may be as follows.

Example of delimiter setting when TSV file is output (setting by character reference)
<property name="delimiter" value="&#09;"/>

Fixed-length record

Describe how to define fixed length record files.

Input

An example of setting for reading the following input file is shown.

TERASOLUNA Batch 5.x corresponds to a format in which record delimitation is judged by line feed and format judged by the number of bytes.

Input file example 1 (record breaks are line feeds)
Sale012016 1   00000011000000000
Sale022017 2   00000022000000000
Sale032018 3   00000033000000000
Input file example 2 (record delimiter is byte number, 32 bytes is 1 record)
Sale012016 1   00000011000000000Sale022017 2   00000022000000000Sale032018 3   00000033000000000
Input file specification
No Field Name Data Type Number of bytes

(1)

branchId

String

6

(2)

year

int

4

(3)

month

int

2

(4)

customerId

String

10

(5)

amount

BigDecimal

10
Class to be converted
public class SalesPlanDetail {

    private String branchId;
    private int year;
    private int month;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}

The setting for reading the above file is as follows.

Bean definition example
<!-- (1) (2) (3) -->
<bean id="reader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:resource="file:#{jobParameters['inputFile']}"
      p:encoding="MS932"
      p:strict="true">
    <property name="bufferedReaderFactory">  <!-- (4) -->
        <bean class="org.springframework.batch.item.file.DefaultBufferedReaderFactory"/>
    </property>
    <property name="lineMapper">  <!-- (5) -->
        <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
            <property name="lineTokenizer">  <!-- (6) -->
                <!-- (7) -->
                <!-- (8) -->
                <!-- (9) -->
                <bean class="org.terasoluna.batch.item.file.transform.FixedByteLengthLineTokenizer"
                      p:names="branchId,year,month,customerId,amount"
                      c:ranges="1-6, 7-10, 11-12, 13-22, 23-32"
                      c:charset="MS932" />
            </property>
            <property name="fieldSetMapper">  <!-- (10) -->
              <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
                    p:targetType="org.terasoluna.batch.functionaltest.app.model.plan.SalesPlanDetail"/>
            </property>
        </bean>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set the input file.

Nothing

(2)

encoding

Sets the character code of the input file.
Default value of character code for the components offered by Spring Batch varies for ItemReader and ItemWriter (Default value of ItemWriter is "UTF-8").
Hence, it is recommended to explicitly set character code even while using default value.

JavaVM default character set

(3)

strict

If true is set, an exception occurs if the input file does not exist(can not be opened).

true

(4)

bufferedReaderFactory

To decide record breaks by line breaks, use the default value org.springframework.batch.item.file.DefaultBufferedReaderFactory. BufferedReader generated by DefaultBufferedReaderFactory acquires up to a newline as one record.

To judge the delimiter of a record by the number of bytes, set org.terasoluna.batch.item.file.FixedByteLengthBufferedReaderFactory provided by TERASOLUNA Batch 5.x. BufferedReader generated by FixedByteLengthBufferedReaderFactory acquires up to the specified number of bytes as one record.
Detailed specifications and usage of FixedByteLengthBufferedReaderFactory will be described later.

DefaultBufferedReaderFactory

(5)

lineMapper

Set org.springframework.batch.item.file.mapping.DefaultLineMapper.

Nothing

(6)

lineTokenizer

Set org.terasoluna.batch.item.file.transform.FixedByteLengthLineTokenizer provided by TERASOLUNA Batch 5.x.

Nothing

(7)

names

Give a name to each item of one record.
Each item can be retrieved using the name set in FieldSet used in FieldSetMapper.
Set each name from the beginning of the record with a comma separator.
When using BeanWrapperFieldSetMapper it is mandatory setting.

Nothing

(8)

ranges
(Constructor argument)

Sets the break position. Set the delimiter position from the beginning of the record, separated by commas.
The unit of each delimiter position is byte, and it is specified in start position - end position format.
The range specified from the record is acquired in the order in which the delimiter positions are set, and stored in FieldSet.
When names of (6) are specified, the delimiter positions are stored in FieldSet in correspondence with names in the order in which they are set.

Nothing

(9)

charset
(Constructor argument)

Set the same character code as (2).

Nothing

(10)

fieldSetMapper

If special conversion processing for character strings and numbers is unnecessary, use org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper, and specify the conversion target class as property targetType. By doing this, we create an instance that automatically sets the value in the field that matches the name of each item set in (6).
If conversion processing is necessary, set the implementation class of org.springframework.batch.item.file.mapping.FieldSetMapper.

Nothing

See How To Extend for the case of implementing FieldSetMapper yourself.
How to use FixedByteLengthBufferedReaderFactory

To read a file that judges record delimiter by byte count, use org.terasoluna.batch.item.file.FixedByteLengthBufferedReaderFactory provided by TERASOLUNA Batch 5.x.

By using FixedByteLengthBufferedReaderFactory, it is possible to acquire up to the number of bytes specified as one record.
The specification of FixedByteLengthBufferedReaderFactory is as follows.

  • Specify byte count of record as constructor argument

  • Generate FixedByteLengthBufferedReader which reads the file with the specified number of bytes as one record

Use of FixedByteLengthBufferedReader is as follows.

  • Reads a file with one byte length specified at instance creation

  • If there is a line feed code, do not discard it and read it by including it in the byte length of one record

  • The file encoding to be used for reading is the value set for FlatFileItemWriter, and it will be used when BufferedReader is generated.

The method of defining FixedByteLengthBufferedReaderFactory is shown below.

<property name="bufferedReaderFactory">
    <bean class="org.terasoluna.batch.item.file.FixedByteLengthBufferedReaderFactory"
        c:byteLength="32"/>  <!-- (1) -->

</property>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

byteLength
(Constructor argument)

Set the number of bytes per record.

Nothing
Components to use when handling Fixed-length files

When dealing with Fixed-length files, it is based on using the component provided by TERASOLUNA Batch 5.x.

FixedByteLengthBufferedReaderFactory

BufferedReader generation class that reads one record from the fixed-length file without line break by the number of bytes of the specified character code

FixedByteLengthLineTokenizer

The FixedLengthTokenizer extension class, separated by the number of bytes corresponding to the multibyte character string
Processing records containing multibyte character strings

When processing records containing multibyte character strings, be sure to use FixedByteLengthLineTokenizer.
The FixedLengthTokenizer provided by Spring Batch separates the record by the number of characters instead of the number of bytes, so there is a possibility that the item will not be extracted as expected.

Since this issue is already reported to JIRA Spring Batch/BATCH-2540, it might be unnecessary in the future.
For the implementation of FieldSetMapper, refer to How To Extend.

Output

An example of setting for writing the following output file is shown.

In order to write a fixed-length file, it is necessary to format the value obtained from the bean according to the number of bytes of the field.
The format execution method differs as follows depending on whether double-byte characters are included or not.

  • If double-byte characters is not included(single-byte characters only and the number of bytes of characters is constant)

    • Format using FormatterLineAggregator.

    • The format is set by the format used in the String.format method.

  • If double-byte characters is included(The number of bytes of characters is not constant depending on the character code)

    • Format with implementation class of FieldExtractor.

First, a setting example in the case where double-byte characters are not included in the output file is shown, followed by a setting example in the case where double-byte characters are included.

The setting when double-byte characters are not included in the output file is shown below.

Output file example
   0012016 10000000001  10000000
   0022017 20000000002  20000000
   0032018 30000000003  30000000
Output file specification
No Field Name Data Type Number of bytes

(1)

branchId

String

6

(2)

year

int

4

(3)

month

int

2

(4)

customerId

String

10

(5)

amount

BigDecimal

10

If the field’s value is less than the number of bytes specified, the rest of the field will be filled with halfwidth space.

Class to be converted
public class SalesPlanDetail {

    private String branchId;
    private int year;
    private int month;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}

The settings for writing the above file are as follows.

Bean definition
<!-- Writer -->
<!-- (1) (2) (3) (4) (5) (6) (7) -->
<bean id="writer"
      class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
      p:resource="file:#{jobParameters['outputFile']}"
      p:encoding="MS932"
      p:lineSeparator="&#x0A;"
      p:appendAllowed="true"
      p:shouldDeleteIfExists="false"
      p:shouldDeleteIfEmpty="false"
      p:transactional="true">
    <property name="lineAggregator">  <!-- (8) -->
        <bean class="org.springframework.batch.item.file.transform.FormatterLineAggregator"
              p:format="%6s%4s%2s%10s%10s"/>  <!-- (9) -->
            <property name="fieldExtractor">  <!-- (10) -->
              <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
                    p:names="branchId,year,month,customerId,amount"/>  <!-- (11) -->
            </property>
        </bean>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set the output file.

Nothing

(2)

encoding

Sets the character code of the output file.
Default value of character code for the components offered by Spring Batch varies for ItemReader and ItemWriter (Default value of ItemReader is "Default character set of JavaVM").
Hence, it is recommended to explicitly set the character code even while using default value.

UTF-8

(3)

lineSeparator

Set the record break(line feed code).
To make it without line breaks, set (empty string).

line.separator of system’s property

(4)

appendAllowed

If true, add to the existing file.
If true, it must be noted that setting value of shouldDeleteIfExists is invalidated.

false

(5)

shouldDeleteIfExists

If appendAllowed is true, it is recommended not to specify a property since this property is invalidated.
If true, delete the file if it already exists.
If false, throw an exception if the file already exists.

true

(6)

shouldDeleteIfEmpty

If true, delete the file for output if the output count is 0.
Since unintended behaviour is likely to happen by combining with other properties, it is recommended not to set it to true. For details, refer Notes for how to output variable length record.

false

(7)

transactional

Set whether to perform transaction control. For details, see Transaction Control.

true

(8)

lineAggregator

Set org.springframework.batch.item.file.transform.FormatterLineAggregator.

Nothing

(9)

format

Set the output format with the format used in the String.format method.

Nothing

(10)

fieldExtractor

If special conversion processing for strings and numbers is unnecessary, you can use org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor.

If conversion processing is necessary, set implementation class of org.springframework.batch.item.file.transform.FieldExtractor.
An example for implementatiion of FieldExtractor to format double-byte characters is written later on.

PassThroughFieldExtractor

(11)

names

Give a name to each item of one record. Set the names of each field from the beginning of the record with a comma.

Nothing
About PassThroughFieldExtractor

Deafult value for property fieldExtractor of FormatterLineAggregator is org.springframework.batch.item.file.transform.PassThroughFieldExtractor.

PassThroughFieldExtractor is a class to return the original item without processing anything, and is used when FieldExtractor will not process anything.

If the item is an array or a collection, it is returned as is, otherwise it is wrapped in an array of single elements.
Example of how to format a field with double-byte character

When formatting for double-byte characters, since the number of bytes per character differs depending on the character code, use the implementation class of FieldExtractor instead of FormatterLineAggregator.

Implementation class of FieldExtractor is to be done as follows.

  • Implement FieldExtractor and override extract method.

  • extract method is to be implemented as below

    • get the value from the item(target bean), and perform the conversion as needed

    • set the value to an array of object and return it.

The format of a field that includes double-byte characters is to be done in the implementation class of FieldExtractor by the following way.

  • Get the number of bytes for the character code

  • Format the value by trimming or padding it according to be number of bytes

Below is a setting example for formatting a field including double-byte characters.

Output file example
   0012016 10000000001  10000000
  番号2017 2 売上高002  20000000
 番号32018 3   売上003  30000000

Use of the output file is the same as the example above.

Bean definition(settings of lineAggregator only)
<property name="lineAggregator">  <!-- (1) -->
    <bean class="org.springframework.batch.item.file.transform.FormatterLineAggregator"
          p:format="%s%4s%2s%s%10s"/>  <!-- (2) -->
        <property name="fieldExtractor">  <!-- (3) -->
            <bean class="org.terasoluna.batch.functionaltest.ch05.fileaccess.plan.SalesPlanFixedLengthFieldExtractor"/>
        </property>
    </bean>
</property>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

lineAggregator

Set org.springframework.batch.item.file.transform.FormatterLineAggregator.

Nothing

(2)

format

Set the output format with the format used in the String.format method.
The number of digits is specified only for fields that do not contain double-byte characters.

Nothing

(3)

fieldExtractor

Set implementation class of FieldExtractor.
An implementation example will be described later.

PassThroughFieldExtractor
Class to be converted
public class SalesPlanDetail {

    private String branchId;
    private int year;
    private int month;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}
Sample implementation of FieldExtractor to format double-byte characters
public class SalesPlanFixedLengthFieldExtractor implements FieldExtractor<SalesPlanDetail> {
    // (1)
    @Override
    public Object[] extract(SalesPlanDetail item) {
        Object[] values = new Object[5];  // (2)

        // (3)
        values[0] = fillUpSpace(item.getBranchId(), 6);  // (4)
        values[1] = item.getYear();
        values[2] = item.getMonth();
        values[3] = fillUpSpace(item.getCustomerId(), 10);  // (4)
        values[4] = item.getAmount();

        return values; // (7)
    }

    // It is a simple impl for example
    private String fillUpSpace(String val, int num) {
        String charsetName = "MS932";
        int len;
        try {
            len = val.getBytes(charsetName).length;  // (5)
        } catch (UnsupportedEncodingException e) {
            // omitted exception handling
        }

        String fillStr = "";
        for (int i = 0; i < (num - len); i++) { // (6)
            fillStr += " ";
        }

        return fillStr + val;
    }
}
Item list of setting contents
No Description

(1)

Implement FieldExtractor class and override extract method.
Set the conversion target class as the type argument of FieldExtractor.

(2)

Define a Object type array to store data after the conversion.

(3)

Get the value from the item(target bean), and perform the conversion as needed, set the value to an array of object.

(4)

Format the field that includes double-byte character.
Refer to (5) and (6) for the details of format process.

(5)

Get the number of bytes for the character code.

(6)

Format the value by trimming or padding it according to be number of bytes.
In the implementation example, white space characters are added before the character string up to the specified number of bytes.

(7)

Returns an array of Object type holding the processing result.

Single String record

Describe the definition method when dealing with a single character string record file.

Input

An example of setting for reading the following input file is shown below.

Input file sample
Summary1:4,000,000,000
Summary2:5,000,000,000
Summary3:6,000,000,000

The setting for reading the above file is as follows.

Bean definition
<!-- (1) (2) (3) -->
<bean id="reader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:resource="file:#{jobParameters['inputFile']}"
      p:encoding="MS932"
      p:strict="true">
    <property name="lineMapper">  <!-- (4) -->
        <bean class="org.springframework.batch.item.file.mapping.PassThroughLineMapper"/>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set the input file.

Nothing

(2)

encoding

Sets the character code of the input file.
Default value of character code for the components offered by Spring Batch varies for ItemReader and ItemWriter (Default value of ItemWriter is "UTF-8").
Hence, it is recommended to explicitly set character code even while using default value.

JavaVM default character set

(3)

strict

If true is set, an exception occurs if the input file does not exist(can not be opened).

true

(4)

lineMapper

Set org.springframework.batch.item.file.mapping.PassThroughLineMapper.
PassThroughLineMapper is a implementation class of LineMapper, and it will return the String value of passed record as it is.

Nothing

Output

The setting for writing the above file is as follows.

Output file example
Summary1:4,000,000,000
Summary2:5,000,000,000
Summary3:6,000,000,000
Bean definition
<!-- Writer -->
<!-- (1) (2) (3) (4) (5) (6) (7) -->
<bean id="writer"
      class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
      p:resource="file:#{jobParameters['outputFile']}"
      p:encoding="MS932"
      p:lineSeparator="&#x0A;"
      p:appendAllowed="true"
      p:shouldDeleteIfExists="false"
      p:shouldDeleteIfEmpty="false"
      p:transactional="true">
    <property name="lineAggregator">  <!-- (8) -->
        <bean class="org.springframework.batch.item.file.transform.PassThroughLineAggregator"/>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set the output file.

Nothing

(2)

encoding

Sets the character code of the output file.
Default value of character code for the components offered by Spring Batch varies for ItemReader and ItemWriter (Default value of ItemReader is "Default character set of JavaVM").
Hence, it is recommended to explicitly set character code even while using default value.

UTF-8

(3)

lineSeparator

Set the record break(line feed code)

line.separator of system’s property

(4)

appendAllowed

If true, add to existing file.
If true, it must be noted that setting value of shouldDeleteIfExists is invalidated.

false

(5)

shouldDeleteIfExists

If appendAllowed is true, it is recommended not to specify the property since the property is invalidated.
If true, delete the file if it already exists.
If false, throw an exception if the file already exists.

true

(6)

shouldDeleteIfEmpty

If true, delete file for output if output count is 0.
Since unintended behaviour is likely to happen by combining with other properties, it is recommended not to set it to true. For details, refer Notes for how to output variable length records.

false

(7)

transactional

Set whether to perform transaction control. For details, see Transaction Control.

true

(8)

lineAggregator

Set org.springframework.batch.item.file.transform.PassThroughLineAggregator.
PassThroughLineAggregator is the implementation class of LineAggregator that will return the converted String value of the item(target Bean) as it is by processing item.toString().

Nothing

Header and Footer

Explain the input / output method when there is a header / footer.

Here, a method of skipping the header footer by specifying the number of lines will be explained.
When the number of records of header / footer is variable and it is not possible to specify the number of lines, use PatternMatchingCompositeLineMapper with reference to Multi format input

Input

Skipping Header

There are 2 ways to skip the header record.

  • Set the number of lines to skip to property linesToSkip of FlatFileItemReader

  • Remove header record in preprocessing by OS command

Input file sample
sales_plan_detail_11
branchId,year,month,customerId,amount
000001,2016,1,0000000001,1000000000
000002,2017,2,0000000002,2000000000
000003,2018,3,0000000003,3000000000

The first 2 lines is the header record.

The setting for reading the above file is as follows.
Skip by using linesToSkip
<bean id="reader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:resource="file:#{jobParameters['inputFile']}"
      p:linesToSkip=value="2">  <!-- (1) -->
    <property name="lineMapper">
        <!-- omitted settings -->
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

linesToSkip

Set the number of header record lines to skipl.

0
Skip by using OS command
# Remove number of lines in header from the top of input file
tail -n +`expr 2 + 1` input.txt > output.txt

Use the tail command and get the 3rd line and after from input.txt, and then write it out to output.txt. Please note that the value specified for option -n + K of tail command is the number of header records + 1.

OS command to skip header record and footer record

By using the head and tail commands, it is possible to skip the header record and footer record by specifying the number of lines.

How to skip the header record

Execute the tail command with option -n +K, and get the lines after K from the target file.

How to skip the footer record

Execute the head command with option -n -K, and get the lines befor K from the target file.

A sample of shell script to skip header record and footer record can be written as follows.

An example of a shell script that removes a specified number of lines from a header / footer
#!/bin/bash

if [ $# -ne 4 ]; then
  echo "The number of arguments must be 4, given is $#." 1>&2
  exit 1
fi

# Input file.
input=$1

# Output file.
output=$2

# Number of lines in header.
header=$3

# Number of lines in footer.
footer=$4

# Remove number of lines in header from the top of input file
# and number of lines in footer from the end,
# and save to output file.
tail -n +`expr ${header} + 1` ${input} | head -n -${footer} > ${output}
Arguments
No Description

(1)

Input file

(2)

Output file

(3)

Number of lines to skip for header

(4)

Number of lines to skip for footer
Retrieving header information

Here shows how to recognize and retrive the header record.

The extraction of header information is implemented as follows.

Settings

  • Write the process for header record in implementation class of org.springframework.batch.item.file.LineCallbackHandler

    • Set the information retrieved in LineCallbackHandler#handleLine() to stepExecutionContext

  • Set implementation class of LineCallbackHandler to property skippedLinesCallback of FlatFileItemReader``

  • Set the number of lines to skip to property linesToSkip of FlatFileItemReader

Reading files and retrieving header information

  • For each line which is skipped by the setting of linesToSkip, LineCallbackHandler#handleLine() is executed

    • Header information is set to stepExecutionContext

Use retrieved header information

  • Get header information from stepExecutionContext and use it in the processing of the data part

An example of implementation for retrieving header record information is shown below.

Bean definition
<bean id="lineCallbackHandler"
      class="org.terasoluna.batch.functionaltest.ch05.fileaccess.module.HoldHeaderLineCallbackHandler"/>

<!-- (1) (2) -->
<bean id="reader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:linesToSkip="2"
      p:skippedLinesCallback-ref="lineCallbackHandler"
      p:resource="file:#{jobParameters['inputFile']}">
    <property name="lineMapper">
        <!-- omitted settings -->
    </property>
</bean>

<batch:job id="jobReadCsvSkipAndReferHeader" job-repository="jobRepository">
    <batch:step id="jobReadCsvSkipAndReferHeader.step01">
        <batch:tasklet transaction-manager="jobTransactionManager">
            <batch:chunk reader="reader"
                         processor="loggingHeaderRecordItemProcessor"
                         writer="writer" commit-interval="10"/>
            <batch:listeners>
                <batch:listener ref="lineCallbackHandler"/>  <!-- (3) -->
            </batch:listeners>
        </batch:tasklet>
    </batch:step>
</batch:job>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

linesToSkip

Set the number of lines to skip.

0

(2)

skippedLinesCallback

Set implementation class of LineCallbackHandler.
An implementation sample will be described later.

Nothing

(2)

listener

Set implementation class of StepExecutionListener.
This setting is needed sinche the LineCallbackHandler set to property skippedLinesCallback of FlatFileItemReader will not be automatically registered as the Listener.
The detailed reason will be described later.

Nothing
About the listener

Since the following two cases are not automatically registered as Listener, it is necessary to add a definition to Listeners at the time of job definition.
(If listener definitions are not added, StepExecutionListener # beforeStep () will not be executed)

  • StepExecutionListener of LineCallbackHandler which is set to skippedLinesCallback of FlatFileItemReader

  • StepExecutionListener implemented to implementation class of Tasklet

    <batch:job id="jobReadCsvSkipAndReferHeader" job-repository="jobRepository">
        <batch:step id="jobReadCsvSkipAndReferHeader.step01">
            <batch:tasklet transaction-manager="jobTransactionManager">
                <batch:chunk reader="reader"
                             processor="loggingHeaderRecordItemProcessor"
                             writer="writer" commit-interval="10"/>
                <batch:listeners>
                    <batch:listener ref="loggingItemReaderListener"/>
                    <!-- mandatory -->
                    <batch:listener ref="lineCallbackHandler"/>
                </batch:listeners>
            </batch:tasklet>
        </batch:step>
    </batch:job>

LineCallbackHandler should be implemented as follows.

  • Implement StepExecutionListener#beforeStep()

    • Implement StepExecutionListener#beforeStep() by either ways shown below

      • Implement StepExecutionListener class and override beforeStep method

      • Implement beforeStep method and annotate with @BeforeStep

    • Get StepExecution in the beforeStep method and save it in the class field

  • Implement LineCallbackHandler#handleLine()

    • Implement LineCallbackHandler class and override handleLine

      • Note that handleLine method will be executed each time skip is proceeded

    • Get stepExecutionContext from StepExecution and set header information to stepExecutionContext

Sample implementation of LineCallbackHandler
@Component
public class HoldHeaderLineCallbackHandler implements LineCallbackHandler {  // (!)
    private StepExecution stepExecution;  // (2)

    @BeforeStep  // (3)
    public void beforeStep(StepExecution stepExecution) {
        this.stepExecution = stepExecution;  // (4)
    }

    @Override  // (5)
    public void handleLine(String line) {
        this.stepExecution.getExecutionContext().putString("header", line);  // (6)
    }
}
Item list of setting contents
No Description

(1)

Implement LineCallbackHandler class and override handleLine.

(2)

Define a field to save StepExecution.

(3)

Implement beforeStep method and annotate it with @BeforeStep.
The signature will be void beforeStep(StepExecution stepExecution).
It is also possible to implement the StepExecutionListener class and override beforeStep method.

(4)

Get the StepExecution and save it to the class field.

(5)

Implement LineCallbackHandler class and override handleLine method.

(6)

Get stepExecutionContext from StepExecution, set header information to stepExecutionContext by using key header.
Here, for simplicity, only the last one line of two lines to be skipped is stored.

Here is a sample of getting the header information from stepExecutionContext and using it for processing of data part.
A sample of using header information in ItemProcessor will be described as an example.
The same can be done when using header information in other components.

The implementation of using header information is done as follows.

  • As like the sample of implementing LineCallbackHandler, implement StepExecutionListener#beforeStep()

  • Get StepExecution in beforeStep method and save it to the class field

  • Get stepExecutionContext and the header information from StepExecution and use it

Sample of how to use header information
@Component
public class LoggingHeaderRecordItemProcessor implements
        ItemProcessor<SalesPlanDetail, SalesPlanDetail> {
    private StepExecution stepExecution;  // (1)

    @BeforeStep  // (2)
    public void beforeStep(StepExecution stepExecution) {
        this.stepExecution = stepExecution;  // (3)
    }

    @Override
    public SalesPlanDetail process(SalesPlanDetail item) throws Exception {
        String headerData = this.stepExecution.getExecutionContext()
                .getString("header");  // (4)
        // omitted business logic
        return item;
    }
}
Item list of setting contents
No Description

(1)

Define a field to save StepExecution.

(2)

Implement beforeStep method and annotate it with @BeforeStep.
The signature will be void beforeStep(StepExecution stepExecution).
It is also possible to implement the StepExecutionListener class and override beforeStep method.

(3)

Get the StepExecution and save it to the class field.

(4)

Get stepExecutionContext from StepExecution, set header information to stepExecutionContext by using key header.
About the use of ExecutionContext of Job/Step

In retrieving header (footer) information, the method is to store the read header information in ExecutionContext of StepExecution, and retrieves it from ExecutionContext when using it.

In the example below, header information is stored in ExecutionContext of StepExecution in order to obtain and use header information within one step. If step is divided by retreiving and using the header information, use ExecutionContext of JobExecution.

For details about ExecutionContext of Job/Step, refer to Architecture of Spring Batch
Skipping Footer

Since Spring Batch nor TERASOLUNA Batch 5.x does not support skipping footer record, it needs to be done by OS command.

Input File Sample
000001,2016,1,0000000001,1000000000
000002,2017,2,0000000002,2000000000
000003,2018,3,0000000003,3000000000
number of items,3
total of amounts,6000000000

The last 2 lines is the footer record.

The setting for reading the above file is as follows.

Skipping by OS command
# Remove number of lines in footer from the end of input file
head -n -2 input.txt > output.txt

Use head command, get the lines above the second line from the last from input.txt, and write it out to output.txt.

It is reported to JIRA Spring Batch/BATCH-2539 that Spring Batch does not have a functions to skip the footer record.
Hence, there is a possibility that not only by OS command, but Spring Batch will be able to skip the footer record in the future.
Retrieving footer information

In Spring Batch and TERASOLUNA Batch 5.x, functions for skipping footer record retreiving footer information is not provided.

Therefore, it needs to be divided into preprocessing OS command and 2 steps as described below.

  • Divide footer record by OS command

  • In 1st step, read the footer record and set footer information to ExecutionContext

  • In 2nd step, retrive footer information from ExecutionContext and use it

Retreiving footer information will be implemented as follows.

Divide footer record by OS command

  • Use OS command to divide the input file to footer part and others

1st step, read the footer record and get footer information

  • Read the footer record and set it to jobExecutionContext

    • Since the steps are different in storing and using footer information, store it in jobExecutionContext.

    • The use of jobExecutionContext is same as the stepExecutionContext explained in Retrieving header information, execpt for the scope of Job and Step.

2nd step, use the retrieved footer information

  • Get the footer information from jobExecutionContext and use it for processing of data part.

An example will be described in which footer information of the following file is taken out and used.

Input File Sample
000001,2016,1,0000000001,1000000000
000002,2017,2,0000000002,2000000000
000003,2018,3,0000000003,3000000000
number of items,3
total of amounts,6000000000

The last 2 lines is footer record.

Divide footer record by OS command

The setting to divide the above file into footer part and others by OS command is as follows.

Skipping by OS command
# Extract non-footer record from input file and save to output file.
head -n -2 input.txt > input_data.txt

# Extract footer record from input file and save to output file.
tail -n 2 input.txt > input_footer.txt

Use head command, write footer part of input.txt to input_footer.txt, and others to input_data.txt.

Output file sample is as follows.

Output file example(input_data.txt)
000001,2016,1,0000000001,1000000000
000002,2017,2,0000000002,2000000000
000003,2018,3,0000000003,3000000000
Output file example(input_footer.txt)
number of items,3
total of amounts,6000000000
Get/Use footer information

Explain how to get and use footer information from a footer record divided by OS command.

The step of reading the footer record is divided into the preprocessing and main processing.
Refer to Flow Controll for details of step dividing.

In the example below, a sample is shown in which footer information is retreived and stored in jobExecutionContext.
Footer information can be used by retreiving it from jobExecutionContext like the same way described in Retrieving header information.

Class to set information of data record
public class SalesPlanDetail {

    private String branchId;
    private int year;
    private int month;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}
Class to set information of footer record
public class SalesPlanDetailFooter implements Serializable {

    // omitted serialVersionUID

    private String name;
    private String value;

    // omitted getter/setter
}

Define the Bean like below.

  • Define ItemReader to read footer record

  • Define ItemReader to read data record

  • Define business logic to retreive footer record

    • In the sample below, it is done by implementing Tasklet

  • Define a job

    • Define a step with a preprocess to get footer information and a main process to read data records.

Bean definition
<!-- ItemReader for reading footer records -->
<!-- (1) -->
<bean id="footerReader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:resource="file:#{jobParameters['footerInputFile']}">
    <property name="lineMapper">
        <!-- omitted other settings -->
    </property>
</bean>

<!-- ItemReader for reading data records -->
<!-- (2) -->
<bean id="dataReader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:resource="file:#{jobParameters['dataInputFile']}">
    <property name="lineMapper">
        <!-- omitted other settings -->
    </property>
</bean>

<bean id="writer"
      class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step">
  <!-- omitted settings -->
</bean>

<!-- Tasklet for reading footer records -->
<bean id="readFooterTasklet"
      class="org.terasoluna.batch.functionaltest.ch05.fileaccess.module.ReadFooterTasklet"/>

<batch:job id="jobReadAndWriteCsvWithFooter" job-repository="jobRepository">
    <!-- (3) -->
    <batch:step id="jobReadAndWriteCsvWithFooter.step01"
            next="jobReadAndWriteCsvWithFooter.step02">
        <batch:tasklet ref="readFooterTasklet"
                       transaction-manager="jobTransactionManager"/>
    </batch:step>
    <!-- (4) -->
    <batch:step id="jobReadAndWriteCsvWithFooter.step02">
        <batch:tasklet transaction-manager="jobTransactionManager">
            <batch:chunk reader="dataReader"
                         writer="writer" commit-interval="10"/>
        </batch:tasklet>
    </batch:step>
    <batch:listeners>
        <batch:listener ref="readFooterTasklet"/> <!-- (5) -->
    </batch:listeners>
</batch:job>
Item list of setting contents
No Item Setting contents Required Default Value

(1)

footerReader

Define ItemReader to read a file with footer record.
Used by injecting it to readFooterTasklet which is executed when retreiving footer information.

(2)

dataReader

Define ItemReader to read a file with data record.

(3)

preprocess step

Define a step to get the footer information.
Implemented at readFooterTasklet. Implementation sample is written later on.

(4)

main process step

A step of retreiving data information and using footer information is defined.
Use dataReader for reader.
In the sample, method to get footer information from jobExecutionContext such as ItemProcessor is not implemented.
Footer information can be retreived and used the same way described in Retrieving header information.

(5)

listeners

Set readFooterTasklet.
Without this setting, JobExecutionListener#beforeJob() implemented in readFooterTasklet will not be executed.
For details, refer to Retrieving header information.

Nothing

An example for reading a file with footer record and storing it to jobExecutionContextis shown below.

The way to make it as the implementation class of Tasklet is as follows.

  • Inject the bean defined footerReader by name using @Inject@ and @Named

  • Set the footer information to jobExecutionContext

Getting footer information
public class ReadFooterTasklet implements Tasklet {
    // (1)
    @Inject
    @Named("footerReader")
    ItemStreamReader<SalesPlanDetailFooter> itemReader;

    private JobExecution jobExecution;

    @BeforeJob
    public void beforeJob(JobExecution jobExecution) {
        this.jobExecution = jobExecution;
    }

    @Override
    public RepeatStatus execute(StepContribution contribution,
            ChunkContext chunkContext) throws Exception {
        ArrayList<SalesPlanDetailFooter> footers = new ArrayList<>();

        // (2)
        itemReader.open(chunkContext.getStepContext().getStepExecution()
                .getExecutionContext());

        SalesPlanDetailFooter footer;
        while ((footer = itemReader.read()) != null) {
            footers.add(footer);
        }

        // (3)
        jobExecution.getExecutionContext().put("footers", footers);

        return RepeatStatus.FINISHED;
    }
}
Item list of setting contents
No Description

(1)

Inject the bean defined footerReader by name using @Inject@ and @Named.

(2)

Use footerReader to read the file with footer record and get the footer information.
To use ItemReader bean defined in implementation class of Tasklet, refer to Creating a tasklet-oriented job

(3)

Get jobExecutionContext from JobExecution, set the footer information to jobExecutionContext by key footers.

Output

Output header information

To output header information to a flat file, implement as follows.

  • Implement org.springframework.batch.item.file.FlatFileHeaderCallback

  • Set the implemented FlatFileHeaderCallback to property headerCallback of FlatFileItemWriter

    • By setting headerCallback, FlatFileHeaderCallback#writeHeader() will be executed at first when processing FlatFileItemWriter

Implement FlatFileHeaderCallback as follows.

  • Implement FlatFileHeaderCallback class and override writeHeader.

  • Write the header information using Writer from the argument.

Sample implementation of FlatFileHeaderCallback is shown below.

Sample implementation of FlatFileHeaderCallback
@Component
// (1)
public class WriteHeaderFlatFileFooterCallback implements FlatFileHeaderCallback {
    @Override
    public void writeHeader(Writer writer) throws IOException {
        // (2)
        writer.write("omitted");
    }
}
Item list of setting contents
No Description

(1)

Implement FlatFileHeaderCallback class and override writeHeader method.

(2)

Write the header information using Writer from the argument.
Write method of FlatFileItemWriter will be executed right after the execution of FlatFileHeaderCallback#writeHeader().
Therefore, printing line break at the end of header information is not needed. The line feed that is printed is the one set when FlatFileItemWriter bean was defined.
Bean definition
<!-- (1) (2) -->
<bean id="writer"
      class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
      p:headerCallback-ref="writeHeaderFlatFileFooterCallback"
      p:lineSeparator="&#x0A;"
      p:resource="file:#{jobParameters['outputFile']}">
    <property name="lineAggregator">
        <!-- omitted settings -->
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

headerCallback

Set implementation class of FlatFileHeaderCallback.

(2)

lineSeparator

Set the record break(line feed code)

line.separator of system’s property
When implementing FlatFileHeaderCallback, printing line feed at the end of header information is not necessary

Right after executing FlatFileHeaderCallback#writeHeader() in FlatFileItemWriter, line feed is printed according to the bean definition, so the line feed at the end of header information does not need to be printed.
Output footer information

To output footer information to a flat file, implement as follows.

  • Implement org.springframework.batch.item.file.FlatFileFooterCallback

  • Set the implemented FlatFileFooterCallback to property footerCallback of FlatFileItemWriter

    • By setting footerCallback, FlatFileHeaderCallback#writeFooter() will be executed at first when processing FlatFileItemWriter

A method of outputting footer information with a flat file will be described.

Implement FlatFileFooterCallback as follows.

  • Output footer information using Writer from the argument.

  • Implement FlatFileFooterCallback class and override writeFooter.

Below is an implementation sample of FlatFileFooterCallback class for a Job to get footer information from ExecutionContext and write it out to a file.

Class to set information of footer record
public class SalesPlanDetailFooter implements Serializable {

    // omitted serialVersionUID

    private String name;
    private String value;

    // omitted getter/setter
}
Implementation Sample of FlatFileFooterCallback
@Component
public class WriteFooterFlatFileFooterCallback implements FlatFileFooterCallback {  // (1)
    private JobExecution jobExecution;

    @BeforeJob
    public void beforeJob(JobExecution jobExecution) {
        this.jobExecution = jobExecution;
    }

    @Override
    public void writeFooter(Writer writer) throws IOException {
        @SuppressWarnings("unchecked")
        ArrayList<SalesPlanDetailFooter> footers = (ArrayList<SalesPlanDetailFooter>) this.jobExecution.getExecutionContext().get("footers");  // (2)

        BufferedWriter bufferedWriter = new BufferedWriter(writer);  // (3)
        // (4)
        for (SalesPlanDetailFooter footer : footers) {
            bufferedWriter.write(footer.getName() +" is " + footer.getValue());
            bufferedWriter.newLine();
            bufferedWriter.flush();
        }
    }
}
Item list of setting contents
No Description

(1)

Implement FlatFileFooterCallback class and override writeFooter method.

(2)

Get footer information form ExecutionContext of the Job using key footers.
In the sample, it uses ArrayList to get several footer informations.

(3)

In the sample, in order to use BufferedWriter.newLine() for printing line feed, it is using Writer from the argument as a parameter to generate BufferedWriter.

(4)

Use the Writer of argument to print footer information.
Bean definition
<bean id="writer"
      class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
      p:resource="file:#{jobParameters['outputFile']}"
      p:footerCallback-ref="writeFooterFlatFileFooterCallback">  <!-- (1) -->
    <property name="lineAggregator">
        <!-- omitted settings -->
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

footerCallback

Set implementation class of FlatFileFooterCallback.

Multiple Files

Describe how to handle multiple files.

Input

To read multiple files of the same record format, use org.springframework.batch.item.file.MultiResourceItemReader.
MultiResourceItemReader can use the specified ItemReader to read multiple files specified by regular expressions.

Implement MultiResourceItemReader as follows.

  • Define bean of MultiResourceItemReader

    • Set file to read to property resources

      • user regular expression to read multiple files

    • Set ItemReader to read files to property delegate

Below is a definition example of MultiResourceItemReader to read multiple files with the following file names.

File to be read (file name)
sales_plan_detail_01.csv
sales_plan_detail_02.csv
sales_plan_detail_03.csv
Bean definition
<!-- (1) (2) -->
<bean id="multiResourceReader"
      class="org.springframework.batch.item.file.MultiResourceItemReader"
      scope="step"
      p:resources="file:input/sales_plan_detail_*.csv"
      p:delegate-ref="reader"/>
</bean>

<!-- (3) -->
<bean id="reader"
      class="org.springframework.batch.item.file.FlatFileItemReader">
    <property name="lineMapper">
      <!-- omitted settings -->
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set multiple input files with regular expressions.

Nothing

(2)

delegate

Set ItemReader where it has the actual file read implementation.

Nothing

(3)

ItemReader with the actual file read implementation

Since property resource is set automatically from MultiResourceItemReader, it is not necessary to set it in Bean definition.

It is unnecessary to specify resource for ItemReader used by MultiResourceItemReader

Since resource of ItemReader delegated from MultiResourceItemReader is automatically set from MultiResourceItemReader, it is not necessary to set it in Bean definition.

Output

Explain how to define multiple files.

To output to a different file for a certain number of cases, use org.springframework.batch.item.file.MultiResourceItemWriter.

MultiResourceItemWriter can output to multiple files for each number specified using the specified ItemWriter.
It is necessary to make the output file name unique so as not to overlap, but ResourceSuffixCreator is provided as a mechanism for doing it.
ResourceSuffixCreator is a class that generates a suffix that makes the file name unique.

For example, if you want to make the output target file a file name outputDir / customer_list_01.csv (01 part is serial number), set it as follows.

  • Set outputDir/customer_list_ to MultiResourceItemWriter

  • Implement a code to generate suffix 01.csv(01 part is serial number) at ResourceSuffixCreator

    • Serial numbers can use the value automatically incremented and passed from MultiResourceItemWriter

  • outputDir/customer_list_01.csv is set to the ItemWriter that is actually used

MultiResourceItemWriter is defined as follows. How to implement ResourceSuffixCreator is described later.

  • Define implementation class of ResourceSuffixCreator

  • Define bean for MultiResourceItemWriter

    • Set output file to property resources

      • Set the file name up to the suffix given to implementation class of ResourceSuffixCreator

    • Set implementation class of ResourceSuffixCreator that generates suffix to property resourceSuffixCreator

    • Set ItemWrite which is to be used to read file to property delegate

    • Set the number of output per file to property itemCountLimitPerResource

Bean definition
<!-- (1) (2) (3) (4) -->
<bean id="multiResourceItemWriter"
      class="org.springframework.batch.item.file.MultiResourceItemWriter"
      scope="step"
      p:resource="file:#{jobParameters['outputDir']}"
      p:resourceSuffixCreator-ref="customerListResourceSuffixCreator"
      p:delegate-ref="writer"
      p:itemCountLimitPerResource="4"/>
</bean>

<!-- (5) -->
<bean id="writer"
      class="org.springframework.batch.item.file.FlatFileItemWriter">
    <property name="lineAggregator">
        <!-- omitted settings -->
    </property>
</bean>

<bean id="customerListResourceSuffixCreator"
      class="org.terasoluna.batch.functionaltest.ch05.fileaccess.module.CustomerListResourceSuffixCreator"/>  <!-- (6) -->
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Sets the state before adding the suffix of the output target file.
A file name with suffix given automatically by MultiResourceItemWriter is set to ItemWriter.

Nothing

(2)

resourceSuffixCreator

Set implementation class of ResourceSuffixCreator.
Default is org.springframework.batch.item.file.SimpleResourceSuffixCreator whice generates suffix "." + index.

SimpleResourceSuffixCreator

(3)

delegate

Set a ItemWriter which actually reads the file.

Nothing

(4)

itemCountLimitPerResource

Set the number of output per file.

Integer.MAX_VALUE

(5)

ItemWriter which actually reads the file.

Since property resource is automatically set from MultiResourceItemWriter, it is not necessary to set it in Bean definition.

Setting of resource of ItemWrite used by MultiResourceItemWriter is not necessary

Since Resource of ItemWriter delegated from MultiResourceItemWriter is automatically set from MultiResourceItemWriter, it is not necessary to set it in the bean definition.

Implement ResourceSuffixCreator as follows.

  • Implement ResourceSuffixCreator and override getSuffix method

  • Use argument’s index and generate suffix to return

    • index is an int type value with initial value 1, and will be incremented for each output file

Sample implementation of ResourceSuffixCreator
// (1)
public class CustomerListResourceSuffixCreator implements ResourceSuffixCreator {
    @Override
    public String getSuffix(int index) {
        return String.format("%02d", index) + ".csv";  // (2)
    }
}
Item list of setting contents
No Description

(1)

Implement ResourceSuffixCreator class and override getSuffix method.

(2)

Use argument’s index to generate suffix to return. index is an int type value with initial value 1, and will be incremented for each output file.

Control Break

How to actually do the Control Break will be described here.

What is Control Break

Control Break process(or Key Break process) is a process method to read sorted records one by one, and handle records with a certain item(key item) as one group.
It is an algorithm that is used mainly for aggregating data, continues counting while key items are the same value, and outputs aggregate values when key items become different values.

In order to perform the control break processing, it is necessary to pre-read the record in order to judge the change of the group. Pre-reading records can be done by using org.springframework.batch.item.support.SingleItemPeekableItemReader.
Also, control break can be processed only in tasklet model. This is because of the premise that the chunk model is based on, which are "processing N data rows defined by one line" and "transaction boundaries every fixed number of lines", does not fit with the control break’s basic algorithm, "proceed at the turn of group".

The execution timing of control break processing and comparison conditions are shown below.

  • Execute control break before processing the target record

    • Keep the previously read record, compare previous record with current record

  • Execute control break after processing the target record

    • Pre-read the next record by SingleItemPeekableItemReader and compare the current record with the next record

A sample for outputting process result from input data using control break is shown below.

Input Data
01,2016,10,1000
01,2016,11,1500
01,2016,12,1300
02,2016,12,900
02,2016,12,1200
Process Result
Header Branch Id : 01,,,
01,2016,10,1000
01,2016,11,1500
01,2016,12,1300
Summary Branch Id : 01,,,3800
Header Branch Id : 02,,,
02,2016,12,900
02,2016,12,1200
Summary Branch Id : 02,,,2100
Implementation Sample of Control Break
@Component
public class ControlBreakTasklet implements Tasklet {

    @Inject
    SingleItemPeekableItemReader<SalesPerformanceDetail> reader; // (1)

    @Inject
    ItemStreamWriter<SalesPerformanceDetail> writer;

    @Override
    public RepeatStatus execute(StepContribution contribution,
            ChunkContext chunkContext) throws Exception {

        // omitted.

        SalesPerformanceDetail previousData = null;   // (2)
        BigDecimal summary = new BigDecimal(0);  //(3)

        List<SalesPerformanceDetail> items = new ArrayList<>();   // (4)

        try {
            reader.open(executionContext);
            writer.open(executionContext);

            while (reader.peek() != null) {   // (5)
                SalesPerformanceDetail data = reader.read(); // (6)

                // (7)
                if (isBreakByBranchId(previousData, data)) {
                    SalesPerformanceDetail beforeBreakData =
                            new SalesPerformanceDetail();
                    beforeBreakData.setBranchId("Header Branch Id : "
                              + currentData.getBranchId());
                    items.add(beforeBreakData);
                }

                // omitted.
                items.add(data);  // (8)

                SalesPerformanceDetail nextData = reader.peek();  // (9)
                summary = summary.add(data.getAmount());

                // (10)
                SalesPerformanceDetail afterBreakData = null;
                if (isBreakByBranchId(nextData, data)) {
                    afterBreakData = new SalesPerformanceDetail();
                    afterBreakData.setBranchId("Summary Branch Id : "
                            + currentData.getBranchId());
                    afterBreakData.setAmount(summary);
                    items.add(afterBreakData);
                    summary = new BigDecimal(0);
                    writer.write(items);  // (11)
                    items.clear();
                }
                previousData = data;  // (12)
            }
        } finally {
            try {
                reader.close();
            } catch (ItemStreamException e) {
            }
            try {
                writer.close();
            } catch (ItemStreamException e) {
            }
        }
        return RepeatStatus.FINISHED;
    }
    // (13)
    private boolean isBreakByBranchId(SalesPerformanceDetail o1,
            SalesPerformanceDetail o2) {
        return (o1 == null || !o1.getBranchId().equals(o2.getBranchId()));
    }
}
Item list of setting contents
No Description

(1)

Inject SingleItemPeekableItemReader.

(2)

Define a variable to set the previously read record.

(3)

Define a variable to set aggregated values for each group.

(4)

Define a variable to set records for each group including the control break’s process result

(5)

Repeat the process until there is no input data.

(6)

Read the record to be processed.

(7)

Execute a control break before target record processing.
In the sample, if it is at the beginning of the group, heading is set stored it the variable defined in (4).

(8)

Set the process result to the variable defined in (4).

(9)

Pre-read the next record.

(10)

Execute a control break after target record processing. In this case, if it is at the end of the group, the aggregated data is set in the trailer and stored in the variable defined in (4).

(11)

Output processing results for each group.

(12)

Store the processing record in the variable defined in (2).

(13)

Judge whether the key item has switched or not.
Bean definition
<!-- (1) -->
<bean id="reader"
      class="org.springframework.batch.item.support.SingleItemPeekableItemReader"
      p:delegate-ref="delegateReader" />  <!-- (2) -->

<!-- (3) -->
<bean id="delegateReader"
      class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
      p:resource="file:#{jobParameters['inputFile']}">
    <property name="lineMapper">
        <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
            <property name="lineTokenizer">
                <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
                      p:names="branchId,year,month,customerId,amount"/>
            </property>
            <property name="fieldSetMapper">
                <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
                      p:targetType="org.terasoluna.batch.functionaltest.app.model.performance.SalesPerformanceDetail"/>
            </property>
        </bean>
    </property>
</bean>
Item list of setting contents
No Description

(1)

Define bean for SingleItemPeekableItemReader. It will be injected to the Tasklet.

(2)

Set the bean of ItemReader that actually reads the file to delegate property.

(3)

Define a bean for ItemReader that actually read the file.

How To Extend

Here, an explanation will be written based on the below case.

Implmementation of FieldSetMapper

Explain how to implement FieldSetMapper yourself.

Implement FieldSetMapper class as follows.

  • Implement FieldSetMapper class and override mapFieldSet method.

  • Get the value from argument’s FieldSet, do any process needed, and then set it to the conversion target bean as a return value

    • The FieldSet class is a class that holds data in association with an index or name, as in the JDBC ResultSet class

    • The FieldSet class holds the value of each field of a record divided by LineTokenizer

    • You can store and retrieve values by specifying an index or name

Here is sample implementation for reading a file that includes data that needs to be converted, such as BigDecimal type with comma and Date type of Japanese calendar format.

Input File Sample
"000001","平成28年1月1日","000000001","1,000,000,000"
"000002","平成29年2月2日","000000002","2,000,000,000"
"000003","平成30年3月3日","000000003","3,000,000,000"
Input file specification
No Field Name Data Type Note

(1)

branchId

String

(2)

Date

Date

Japanese calendar format

(3)

customerId

String

(4)

amount

BigDecimal

include comma
Class to be converted
public class UseDateSalesPlanDetail {

    private String branchId;
    private Date date;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}
Implementation Sample of FieldSetMapper
@Component
public class UseDateSalesPlanDetailFieldSetMapper implements FieldSetMapper<UseDateSalesPlanDetail> {  // (1)
    /**
     * {@inheritDoc}
     *
     * @param fieldSet {@inheritDoc}
     * @return Sales performance detail.
     * @throws BindException {@inheritDoc}
     */
    @Override
    public UseDateSalesPlanDetail mapFieldSet(FieldSet fieldSet) throws BindException {
        UseDateSalesPlanDetail item = new UseDateSalesPlanDetail();  // (2)

        item.setBranchId(fieldSet.readString("branchId"));  // (3)

        // (4)
        DateFormat japaneseFormat = new SimpleDateFormat("GGGGy年M月d日", new Locale("ja", "JP", "JP"));
        try {
            item.setDate(japaneseFormat.parse(fieldSet.readString("date")));
        } catch (ParseException e) {
            // omitted exception handling
        }

        // (5)
        item.setCustomerId(fieldSet.readString("customerId"));

        // (6)
        DecimalFormat decimalFormat = new DecimalFormat();
        decimalFormat.setParseBigDecimal(true);
        try {
            item.setAmount((BigDecimal) decimalFormat.parse(fieldSet.readString("amount")));
        } catch (ParseException e) {
            // omitted exception handling
        }

        return item;  // (7)
    }
}
Item list of setting contents
No Description

(1)

Implement FieldSetMapper class and override mapFieldSet method. Set conversion target class for type argument of FieldSetMapper.

(2)

Define a variable of conversion target class to store converted data.

(3)

Get branchId from argument’s FieldSet, and store it to conversion target class variable.
Conversion for branchId is not done in the sample since it is not necessary.

(4)

Get date from argument’s FieldSet, and store it to conversion target class variable.
Use SimpleDateFormat to convert Japanese calendar format date to Date type value.

(5)

Get customerId from argument’s FieldSet, and store it to conversion target class variable.
Conversion for customerId is not done in the sample since it is not necessary.

(4)

Get amount from argument’s FieldSet, and store it to conversion target class variable.
Use DecimalFormat to convert value with comma to BigDecimal type value.

(7)

Return the conversion target class holding the processing result.
Getting value from FieldSet class

The FieldSet class has methods corresponding to various data types for obtaining stored values such as listed below.
When generating FieldSet if data is stored in association with the field name, it is possible to get data by specifying that name or by specifying the index.

  • readString()

  • readInt()

  • readBigDecimal()

etc

XML File

Describe the definition method when dealing with XML files.

For the conversion process between Bean and XML (O / X (Object / XML) mapping), use the library provided by Spring Framework.
Implementation classes are provided as Marshaller and Unmarshaller using XStream, JAXB, etc. as libraries for converting between XML files and objects.
Use one suitable for your situation.

Below are features and points for adopting JAXB and XStream.

JAXB

  • Specify the bean to be converted in the bean definition file

  • Validation using a schema file can be performed

  • It is useful when the schema is defined externally and the specification of the input file is strictly determined

XStream

  • You can map XML elements and bean fields flexibly in the bean definition file

  • It is useful when you need to flexibly map beans

Here is a sample using JAXB.

Input

For inputting XML file, use org.springframework.batch.item.xml.StaxEventItemReader provided by Spring Batch.
StaxEventItemReader can read the XML file by mapping the XML file to the bean using the specified Unmarshaller.

Implement StaxEventItemReader as follows.

  • Add @XmlRootElement to the conversion target class of XML root element

  • Set below property to StaxEventItemReader

    • Set the file to read to property resource

    • Set the name of the root element to property fragmentRootElementName

    • Set org.springframework.oxm.jaxb.Jaxb2Marshaller to property unmarshaller

  • Set below property to Jaxb2Marshaller

    • Set conversion target classs in list format to property classesToBeBound

    • To validate using schema file, set the 2 properties as below

      • Set the schema file for validation to property schema

      • Set implementation class of ValidationEventHandler to property validationEventHandler to handle events occured during the validation

Here is the sample setting to read the input file below.

Input File Sample
<?xml version="1.0" encoding="UTF-8"?>
<records>
    <SalesPlanDetail>
        <branchId>000001</branchId>
        <year>2016</year>
        <month>1</month>
        <customerId>0000000001</customerId>
        <amount>1000000000</amount>
    </SalesPlanDetail>
    <SalesPlanDetail>
        <branchId>000002</branchId>
        <year>2017</year>
        <month>2</month>
        <customerId>0000000002</customerId>
        <amount>2000000000</amount>
    </SalesPlanDetail>
    <SalesPlanDetail>
        <branchId>000003</branchId>
        <year>2018</year>
        <month>3</month>
        <customerId>0000000003</customerId>
        <amount>3000000000</amount>
    </SalesPlanDetail>
</records>
Class to be converted
@XmlRootElement(name = "SalesPlanDetail")  // (1)
public class SalesPlanDetailToJaxb {

    private String branchId;
    private int year;
    private int month;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}
Item list of setting contents
No Description

(1)

Add @XmlRootElement annotation to make this as the root tag of XML.
Set SalesPlanDetail for the tag name.

The setting for reading the above file is as follows.

Bean definition
<!-- (1) (2) (3) -->
<bean id="reader"
      class="org.springframework.batch.item.xml.StaxEventItemReader" scope="step"
      p:resource="file:#{jobParameters['inputFile']}"
      p:fragmentRootElementName="SalesPlanDetail"
      p:strict="true">
    <property name="unmarshaller">  <!-- (4) -->
        <!-- (5) (6) -->
        <bean class="org.springframework.oxm.jaxb.Jaxb2Marshaller"
              p:schema="file:files/test/input/ch05/fileaccess/SalesPlanDetail.xsd"
              p:validationEventHandler-ref="salesPlanDetailValidationEventHandler">
            <property name="classesToBeBound">  <!-- (7) -->
                <list>
                    <value>org.terasoluna.batch.functionaltest.ch05.fileaccess.model.plan.SalesPlanDetailToJaxb</value>
                </list>
            </property>
        </bean>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set the input file.

Nothing

(2)

fragmentRootElementName

Set the name of the root element.
If there are several target objects, use fragmentRootElementNames.

Nothing

(3)

strict

If true is set, an exception occurs if the input file does not exist(can not be opened).

true

(4)

unmarshaller

Set the unmarshaller.
Set Bean of org.springframework.oxm.jaxb.Jaxb2Marshaller when using JAXB.

Nothing

(5)

schema

Set shema file for validation.

(6)

validationEventHandler

Set implementation class of ValidationEventHandler to handle events occured during the validation.
Sample implementation of ValidationEventHandler is described later on.

(7)

classesToBeBound

Set conversion target classes in list format.

Nothing
Sample implementation of ValidationEventHandler
@Component
// (1)
public class SalesPlanDetailValidationEventHandler implements ValidationEventHandler {
    /**
     * Logger.
     */
    private static final Logger logger =
            LoggerFactory.getLogger(SalesPlanDetailValidationEventHandler.class);

    @Override
    public boolean handleEvent(ValidationEvent event) {
        // (2)
        logger.error("[EVENT [SEVERITY:{}] [MESSAGE:{}] [LINKED EXCEPTION:{}]" +
                " [LOCATOR: [LINE NUMBER:{}] [COLUMN NUMBER:{}] [OFFSET:{}]" +
                " [OBJECT:{}] [NODE:{}] [URL:{}] ] ]",
                event.getSeverity(),
                event.getMessage(),
                event.getLinkedException(),
                event.getLocator().getLineNumber(),
                event.getLocator().getColumnNumber(),
                event.getLocator().getOffset(),
                event.getLocator().getObject(),
                event.getLocator().getNode(),
                event.getLocator().getURL());
        return false;  // (3)
    }
}
Item list of setting contents
No Description

(1)

Implement ValidationEventHandler class and override handleEvent method.

(2)

Get event information from argument’s event(ValidationEvent), and do any process needed.
In the sample, logging is proceeded.

(3)

Return false to end the search process. Return true to continue the search process.
Return false to end this operation by generating appropriate UnmarshalException, ValidationException or MarshalException.
Adding dependency library

Library dependency needs to be added as below when using Spring Object/Xml Marshalling provided by Spring Framework such as org.springframework.oxm.jaxb.Jaxb2Marshaller.

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-oxm</artifactId>
</dependency>

Output

Use org.springframework.batch.item.xml.StaxEventItemWriter provided by Spring Batch for outputting XML file.
StaxEventItemWriter can output an XML file by mapping the bean to XML using the specified Marshaller.

Implement StaxEventItemWriter as follows.

  • Do the below setting to conversion target class

    • Add @XmlRootElement to the class as it is to be the root element of the XML

    • Use @XmlType annotation to set orders for outputting fields

    • If there is a field to be excluded from conversion to XML, add @XmlTransient to the getter method of it’s field

  • Set below properties to StaxEventItemWriter

    • Set output target file to property resource

    • Set org.springframework.oxm.jaxb.Jaxb2Marshaller to property marshaller

  • Set below property to Jaxb2Marshaller

    • Set conversion target classes in list format to property classesToBeBound

Here is a sample for outputting below file.

Output file example
<?xml version="1.0" encoding="UTF-8"?>
<records>
  <Customer>
    <customerId>001</customerId>
    <customerName>CustomerName001</customerName>
    <customerAddress>CustomerAddress001</customerAddress>
    <customerTel>11111111111</customerTel>
    <chargeBranchId>001</chargeBranchId></Customer>
  <Customer>
    <customerId>002</customerId>
    <customerName>CustomerName002</customerName>
    <customerAddress>CustomerAddress002</customerAddress>
    <customerTel>11111111111</customerTel>
    <chargeBranchId>002</chargeBranchId></Customer>
  <Customer>
    <customerId>003</customerId>
    <customerName>CustomerName003</customerName>
    <customerAddress>CustomerAddress003</customerAddress>
    <customerTel>11111111111</customerTel>
    <chargeBranchId>003</chargeBranchId>
  </Customer>
</records>
About XML file fomatX(line break and indents)

In the sample above, the output XML file has been formatted(has line break and indents), but the actual XML will not be formatted.

Jaxb2Marshaller has a function to format it when outputting the XML file, but it does not work as is it expected.
This issue is being discussed in the Spring Forum, and might be fixed in the future.

To avoid this and output the formatted XML, set marshallerProperties as below.

<property name="marshaller">
    <bean class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
        <property name="classesToBeBound">
            <!-- omitted settings -->
        </property>
        <property name="marshallerProperties">
            <map>
                <entry>
                    <key>
                        <util:constant
                            static-field="javax.xml.bind.Marshaller.JAXB_FORMATTED_OUTPUT"/>
                    </key>
                    <value type="java.lang.Boolean">true</value>
                </entry>
            </map>
        </property>
    </bean>
</property>
Class to be converted
@XmlRootElement(name = "Customer")  // (2)
@XmlType(propOrder={"customerId", "customerName", "customerAddress",
        "customerTel", "chargeBranchId"})  // (2)
public class CustomerToJaxb {

    private String customerId;
    private String customerName;
    private String customerAddress;
    private String customerTel;
    private String chargeBranchId;
    private Timestamp createDate;
    private Timestamp updateDate;

    // omitted getter/setter

    @XmlTransient  // (3)
    public Timestamp getCreateDate() { return createDate; }

    @XmlTransient  // (3)
    public Timestamp getUpdateDate() { return updateDate; }
}
Item list of setting contents
No Description

(1)

Add @XmlRootElement annotation to make this as the root tag of XML.
Set Customer for the tag name.

(2)

Use @XmlType annotation to set field output order.

(3)

Add @XmlTransient to getter method of fileds which is to be excluded from XML conversion.

The settings for writing the above file are as follows.

Bean definition
<!-- (1) (2) (3) (4) (5) (6) -->
<bean id="writer"
      class="org.springframework.batch.item.xml.StaxEventItemWriter" scope="step"
      p:resource="file:#{jobParameters['outputFile']}"
      p:encoding="MS932"
      p:rootTagName="records"
      p:overwriteOutput="true"
      p:shouldDeleteIfEmpty="false"
      p:transactional="true">
    <property name="marshaller">  <!-- (7) -->
        <bean class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
            <property name="classesToBeBound">  <!-- (8) -->
                <list>
                    <value>org.terasoluna.batch.functionaltest.ch05.fileaccess.model.mst.CustomerToJaxb</value>
                </list>
            </property>
        </bean>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

resource

Set output file

Nothing

(2)

encoding

Set character encoding for output file
Default value of character code for the component offered by Spring Batch varies for ItemReader and ItemWriter (Default value of ItemReader is "Default character set of JavaVM").
Hence, it is recommended to explicitly set character code even while using default value.

UTF-8

(3)

rootTagName

Set XML root tag name.

(4)

overwriteOutput

If true, delete the file if it already exists.
If false, throw an exception if the file already exists.

true

(5)

shouldDeleteIfEmpty

If true, delete the file for output if output count is 0.
Since unintended behaviour is likely to happen by combining with other properties, it is recommended not to set it to true. For details, refer Notes for how to output variable length record.

false

(6)

transactional

Set whether to perform transaction control. For details, see Transaction Control.

true

(7)

marshaller

Set the marshaller. Set org.springframework.oxm.jaxb.Jaxb2Marshaller when using JAXB.

Nothing

(8)

classesToBeBound

Set conversion target classes in list format.

Nothing
Adding dependency library

Library dependency needs to be added as below when using Spring Object/Xml Marshalling provided by Spring Framework such as org.springframework.oxm.jaxb.Jaxb2Marshaller.

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-oxm</artifactId>
</dependency>
Output Header / Footer

For output of header and footer, use the implementation class of org.springframework.batch.item.xml.StaxWriterCallback.

Set implementation of headerCallback for header output, and footerCallback for footer output.

Below is a sample of output file.
Header is printed right after the root tag’s openning element, and footer is printed right before the root element’s closing tag.

Output file example
<?xml version="1.0" encoding="UTF-8"?>
<records>
<!-- Customer list header -->
  <Customer>
    <customerId>001</customerId>
    <customerName>CustomerName001</customerName>
    <customerAddress>CustomerAddress001</customerAddress>
    <customerTel>11111111111</customerTel>
    <chargeBranchId>001</chargeBranchId></Customer>
  <Customer>
    <customerId>002</customerId>
    <customerName>CustomerName002</customerName>
    <customerAddress>CustomerAddress002</customerAddress>
    <customerTel>11111111111</customerTel>
    <chargeBranchId>002</chargeBranchId></Customer>
  <Customer>
    <customerId>003</customerId>
    <customerName>CustomerName003</customerName>
    <customerAddress>CustomerAddress003</customerAddress>
    <customerTel>11111111111</customerTel>
    <chargeBranchId>003</chargeBranchId>
  </Customer>
<!-- Customer list footer -->
</records>
About XML file fomatX(line break and indents)

In the sample above, the output XML file has been formatted(has line break and indents), but the actual XML will not be formatted.

Refer to About XML file fomatX(line break and indents) for details.

To output the above file, do the setting as below.

Bean definition
<!-- (1) (2) -->
<bean id="writer"
      class="org.springframework.batch.item.xml.StaxEventItemWriter" scope="step"
      p:resource="file:#{jobParameters['outputFile']}"
      p:headerCallback-ref="writeHeaderStaxWriterCallback"
      p:footerCallback-ref="writeFooterStaxWriterCallback">
    <property name="marshaller">
        <!-- omitted settings -->
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

headerCallback

Set implementation class of StaxWriterCallback.

(2)

footerCallback

Set implementation class of StaxWriterCallback.

Implement StaxWriterCallback as follows.

  • Implement StaxWriterCallback class and override write method

  • Print header/footer by using the argument’s XMLEventWriter

Implementation Sample of StaxWriterCallback
@Component
public class WriteHeaderStaxWriterCallback implements StaxWriterCallback { // (1)
    @Override
    public void write(XMLEventWriter writer) throws IOException {
        XMLEventFactory factory = XMLEventFactory.newInstance();
        try {
            writer.add(factory.createComment(" Customer list header ")); // (2)
        } catch (XMLStreamException e) {
            // omitted exception handling
        }
    }
}
Item list of setting contents
No Description

(1)

Implement StaxWriterCallback class and override write method.

(2)

Print header/footer by using the argument’s XMLEventWriter
XML output using XMLEventFactory

In the output of the XML file using the XMLEventWriter class, you can efficiently generate XMLEvent by using the XMLEventFactory class.

The XMLEventWriter class has an add method defined, which takes an XMLEvent object as an argument and outputs an XML file.
Since it is very time consuming to generate an XMLEvent object each time, use the XMLEventFactory class which can easily generate XMLEvent.
In the XMLEventFactory class, methods corresponding to the event to be created are defined, such as createStartDocument method and createStartElement method.

Multi format

Describe the definition method when dealing with multi format file.

As described in Overview, multi format is basically (Header N Rows + Data N Rows + Trailer N Rows) * N + Footer N Rows format, but there are other format patterns like below.

  • When there is a footer record or not

  • When there are records with different formats in the same record classification

    • eg) there is a data record that has 5 items and a data record with 6 items in data part

Although there are several patterns to multi format file, implementation method will be the same.

Input

Use org.springframework.batch.item.file.mapping.PatternMatchingCompositeLineMapper provided by Spring Batch for readeing multi format file.
In multi format file, each record needs to be mapped to defferent bean for each format.
PatternMatchingCompositeLineMapper will select the LineTokenizer and FieldSetMapper to use for the record by regular expression.

For example, LineTokenizers to use can be selected like below.

  • Use userTokenizer if the beginning of the record matches to regular expression USER*

  • Use lineATokenizer if the beginning of the record matches to regular expression LINEA*

Restrictions on the format of records when reading multi-format files

In order to read a multi-format file, it must be in a format that can distinguish record classification by regular expression.

Implement PatternMatchingCompositeLineMapper as follows.

  • Define a class with record division for conversino target class, and inherit this class to each classes of each record division

  • Define LineTokenizer and FieldSetMapper to map each record to bean

  • Define PatternMatchingCompositeLineMapper

    • Set LineTokenizer that correspond to each record division to property tokenizers

    • Set FieldSetMapper that correspond to each record division to property fieldSetMappers

Define a class with record division for conversino target class, and inherit this class to each classes of each record division

ItemProcessor has a specification that takes one type as an argument.

However, if you simply map PatternMatchingCompositeLineMapper to a multi-format file to a different bean for each record division, ItemProcessor can not handle multiple types as it takes one type as an argument.

Therefore, it is possible to solve this by giving an inheritance relation to the class to be converted and specifying a superclass as the type of the argument of ItemProcessor.

The class diagram of the conversion target class and the definition sample of ItemProcessor are shown below.

Conversion target class definition when loading multiple formats
Class diagram of conversion target class
Implementation Sample of ItemProcessor
public class MultiLayoutItemProcessor implements
        ItemProcessor<SalesPlanDetailMultiLayoutRecord, String> {
    @Override
    // (1)
    public String process(SalesPlanDetailMultiLayoutRecord item) throws Exception {
        String record = item.getRecord();  // (2)

        switch (record) {  // (3)
        case "H":
            // omitted business logic
        case "D":
            // omitted business logic
        case "T":
            // omitted business logic
        case "E":
            // omitted business logic
        default:
            // omitted exception handling
        }
    }
}
Item list of setting contents
No Description

(1)

Set the superclass of the class to be converted whose inheritance relation is given as the argument of ItemProcessor.

(2)

Get the record division from item.
Actual classes are different depending on each record division, but record divison can be retrieved by polymorphism.

(3)

Judge the record division and process things needed for each record division.
Perform class conversions as needed.

Here is a setting sample and implementation sample for reading below input file.

Input File Sample
H,Sales_plan_detail header No.1
D,000001,2016,1,0000000001,100000000
D,000001,2016,1,0000000002,200000000
D,000001,2016,1,0000000003,300000000
T,000001,3,600000000
H,Sales_plan_detail header No.2
D,00002,2016,1,0000000004,400000000
D,00002,2016,1,0000000005,500000000
D,00002,2016,1,0000000006,600000000
T,00002,3,1500000000
H,Sales_plan_detail header No.3
D,00003,2016,1,0000000007,700000000
D,00003,2016,1,0000000008,800000000
D,00003,2016,1,0000000009,900000000
T,00003,3,2400000000
E,3,9,4500000000

Below is the bean definition sample of conversion target class.

Class to be converted
/**
 * Model of record indicator of sales plan detail.
 */
public class SalesPlanDetailMultiLayoutRecord {

    protected String record;

    // omitted getter/setter
}

/**
 * Model of sales plan detail header.
 */
public class SalesPlanDetailHeader extends SalesPlanDetailMultiLayoutRecord {

    private String description;

    // omitted getter/setter
}

/**
 * Model of Sales plan Detail.
 */
public class SalesPlanDetailData extends SalesPlanDetailMultiLayoutRecord {

    private String branchId;
    private int year;
    private int month;
    private String customerId;
    private BigDecimal amount;

    // omitted getter/setter
}

/**
 * Model of Sales plan Detail.
 */
public class SalesPlanDetailTrailer extends SalesPlanDetailMultiLayoutRecord {

    private String branchId;
    private int number;
    private BigDecimal total;

    // omitted getter/setter
}

/**
 * Model of Sales plan Detail.
 */
public class SalesPlanDetailEnd extends SalesPlanDetailMultiLayoutRecord {
    // omitted getter/setter

    private int headNum;
    private int trailerNum;
    private BigDecimal total;

    // omitted getter/setter
}

The setting for reading the above file is as follows.

Bean definition example
<!-- (1) -->
<bean id="headerDelimitedLineTokenizer"
      class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
      p:names="record,description"/>

<bean id="dataDelimitedLineTokenizer"
      class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
      p:names="record,branchId,year,month,customerId,amount"/>

<bean id="trailerDelimitedLineTokenizer"
      class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
      p:names="record,branchId,number,total"/>

<bean id="endDelimitedLineTokenizer"
      class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
      p:names="record,headNum,trailerNum,total"/>

<!-- (2) -->
<bean id="headerBeanWrapperFieldSetMapper"
      class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
      p:targetType="org.terasoluna.batch.functionaltest.ch05.fileaccess.model.plan.SalesPlanDetailHeader"/>

<bean id="dataBeanWrapperFieldSetMapper"
      class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
      p:targetType="org.terasoluna.batch.functionaltest.ch05.fileaccess.model.plan.SalesPlanDetailData"/>

<bean id="trailerBeanWrapperFieldSetMapper"
      class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
      p:targetType="org.terasoluna.batch.functionaltest.ch05.fileaccess.model.plan.SalesPlanDetailTrailer"/>

<bean id="endBeanWrapperFieldSetMapper"
      class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
      p:targetType="org.terasoluna.batch.functionaltest.ch05.fileaccess.model.plan.SalesPlanDetailEnd"/>

<bean id="reader"
    class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
    p:resource="file:#{jobParameters['inputFile']}">
    <property name="lineMapper">  <!-- (3) -->
        <bean class="org.springframework.batch.item.file.mapping.PatternMatchingCompositeLineMapper">
            <property name="tokenizers">  <!-- (4) -->
                <map>
                    <entry key="H*" value-ref="headerDelimitedLineTokenizer"/>
                    <entry key="D*" value-ref="dataDelimitedLineTokenizer"/>
                    <entry key="T*" value-ref="trailerDelimitedLineTokenizer"/>
                    <entry key="E*" value-ref="endDelimitedLineTokenizer"/>
                </map>
            </property>
            <property name="fieldSetMappers">  <!-- (5) -->
                <map>
                    <entry key="H*" value-ref="headerBeanWrapperFieldSetMapper"/>
                    <entry key="D*" value-ref="dataBeanWrapperFieldSetMapper"/>
                    <entry key="T*" value-ref="trailerBeanWrapperFieldSetMapper"/>
                    <entry key="E*" value-ref="endBeanWrapperFieldSetMapper"/>
                </map>
            </property>
        </bean>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

The LineTokenizer corresponding to each record

Define LineTokenizer that corresponds to each record.

(2)

The FieldSetMapper corresponding to each record

Define FieldSetMapper that corresponds to each record.

(3)

lineMapper

Set org.springframework.batch.item.file.mapping.PatternMatchingCompositeLineMapper.

Nothing

(3)

tokenizers

Set LineTokenizer corresponding to each record in map format.
Set regular expression to determine record for key, and set the LineTokenizer to use for value-ref.

Nothing

(4)

tokenizers

Set FieldSetMapper corresponding to each record in map format.
Set regular expression to determine record for key, and set the FieldSetMapper to use for value-ref.

Nothing

Output

Describe the definition method when dealing with multi format file.

For reading multi format file PatternMatchingCompositeLineMapper was provided to determine which LineTokenizer and FieldSetMapper to use for each record division.
However for writing, no similar components are provided.

Therefore, processing up to conversion target class to record (character string) within ItemProcessor is carried out, and ItemWriter writes the received character string as it is to achieve writing of multi format file .

Implement multi format output as follows.

  • ItemProcessor converts the conversion target class to a record (character string) and passes it to ItemWriter

    • In the sample, define LineAggregator and FieldExtractor for each record division and use it by injecting it with ItemProcessor

  • ItemWriter writes the received character string as it is to the file

    • Set PassThroughLineAggregator to property lineAggregator of ItemWriter

    • PassThroughLineAggregator is LineAggregator which returns item.toString () result of received item

Here is a setting sample and implementation sample for writing below output file.

Output file example
H,Sales_plan_detail header No.1
D,000001,2016,1,0000000001,100000000
D,000001,2016,1,0000000002,200000000
D,000001,2016,1,0000000003,300000000
T,000001,3,600000000
H,Sales_plan_detail header No.2
D,00002,2016,1,0000000004,400000000
D,00002,2016,1,0000000005,500000000
D,00002,2016,1,0000000006,600000000
T,00002,3,1500000000
H,Sales_plan_detail header No.3
D,00003,2016,1,0000000007,700000000
D,00003,2016,1,0000000008,800000000
D,00003,2016,1,0000000009,900000000
T,00003,3,2400000000
E,3,9,4500000000

Definition of conversion target class and ItemProcessor sample, notes are the same as Multi format Input.

Settings to output above file is as below. Bean definition sample for ItemProcessor is written later.

Bean definition example
<!-- (1) -->
<bean id="headerDelimitedLineAggregator"
      class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
    <property name="fieldExtractor">
        <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
              p:names="record,description"/>
    </property>
</bean>

<bean id="dataDelimitedLineAggregator"
      class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
    <property name="fieldExtractor">
        <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
              p:names="record,branchId,year,month,customerId,amount"/>
    </property>
</bean>

<bean id="trailerDelimitedLineAggregator"
      class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
    <property name="fieldExtractor">
        <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
              p:names="record,branchId,number,total"/>
    </property>
</bean>

<bean id="endDelimitedLineAggregator"
      class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
    <property name="fieldExtractor">
        <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
              p:names="record,headNum,trailerNum,total"/>
    </property>
</bean>


<bean id="writer" class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
      p:resource="file:#{jobParameters['outputFile']}"/>
    <property name="lineAggregator">  <!-- (2) -->
        <bean class="org.springframework.batch.item.file.transform.PassThroughLineAggregator"/>
    </property>
</bean>
Item list of setting contents
No Property Name Setting contents Required Default Value

(1)

The LineAggregator and FieldExtractor corresponding to each record division

Define LineAggregator and FieldExtractor.
Use LineAggregator by injecting it to ItemProcessor.

(2)

lineAggregator

Set org.springframework.batch.item.file.transform.PassThroughLineAggregator.

Nothing

Implementation sample of ItemProcessor is shown below.
In this sample, only the process of converting the received item to a string and passing it to ItemWriter is performed.

Sample Implementation of ItemProcessor
public class MultiLayoutItemProcessor implements
        ItemProcessor<SalesPlanDetailMultiLayoutRecord, String> {

    // (1)
    @Inject
    @Named("headerDelimitedLineAggregator")
    DelimitedLineAggregator<SalesPlanDetailMultiLayoutRecord> headerDelimitedLineAggregator;

    @Inject
    @Named("dataDelimitedLineAggregator")
    DelimitedLineAggregator<SalesPlanDetailMultiLayoutRecord> dataDelimitedLineAggregator;

    @Inject
    @Named("trailerDelimitedLineAggregator")
    DelimitedLineAggregator<SalesPlanDetailMultiLayoutRecord> trailerDelimitedLineAggregator;

    @Inject
    @Named("endDelimitedLineAggregator")
    DelimitedLineAggregator<SalesPlanDetailMultiLayoutRecord> endDelimitedLineAggregator;

    @Override
    // (2)
    public String process(SalesPlanDetailMultiLayoutRecord item) throws Exception {
        String record = item.getRecord();  // (3)

        switch (record) {  // (4)
        case "H":
            return headerDelimitedLineAggregator.aggregate(item);  // (5)
        case "D":
            return dataDelimitedLineAggregator.aggregate(item);  // (5)
        case "T":
            return trailerDelimitedLineAggregator.aggregate(item);  // (5)
        case "E":
            return endDelimitedLineAggregator.aggregate(item);  // (5)
        default:
            throw new IncorrectRecordClassificationException(
                    "Record classification is incorrect.[value:" + record + "]");
        }
    }
}
Item list of setting contents
No Description

(1)

Inject LineAggregator corresponding to each record division.

(2)

Set the superclass of the class to be converted whose inheritance relation is given as the argument of ItemProcessor.

(3)

Get the record division from item.

(4)

Judge record division and do any process for each record division.

(5)

Use LineAggregator corresponding to each record division to convert the conversion target class to a record (character string) and pass it to ItemWriter.
TERASOLUNA Batch Framework for Java (5.x) Development Guideline - version 5.0.1.RELEASE, 2017-9-27
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