TERASOLUNA Batch Framework for Java (5.x) Development Guideline - version 5.1.1.RELEASE, 2018-3-16
> INDEX

Overview

Create a job which inputs or outputs data by accessing a file.

Note that, since this section is explained based on TERASOLUNA Batch 5.x Development guideline, refer File access for details.

Background, process overview and business specifications of Explanation of application to be created are listed below.

Background

Some mass retail stores issue point cards for members.
Membership types include "Gold member", "Normal member" and the services are provided based on membership type.
As a part of the service, 100 points are added for "gold members" and 10 points are added for "normal members" at the end of the month, for the members who have purchased a product during that month.

Process overview

TERASOLUNA Batch 5.x will be using an application as a monthly batch process which adds points based on the membership type.

Business specifications

Business specifications are as given below.

  • When the product purchasing flag is "1"(process target), points are added based on membership type

    • Add 100 points when membership type is "G"(gold member) and add 10 points when membership type is "N"(Normal member)

  • Product purchasing flag is updated to "0" (initial status) after adding points

  • Upper limit of points is 1,000,000 points

  • If the points exceed 1,000,000 points after adding points, they are adjusted to 1,000,000 points

File specifications

Specifications of member information file which acts as an input and output resource are shown below.

Member information file (Variable length CSV format)
No Field name Data type Number of digits Explanation

1

Member Id

Character string

8

Indicates a fixed 8 digit number which uniquely identifies a member.

2

Membership type

Character string

1

Membership type is as shown below.
"G"(Gold member), "N"(Normal member)

3

Product purchasing flag

Character string

1

It shows whether you have purchased a product in the month.
It is updated to "1" (process target) when the product is purchased and to "0" (initial status) during monthly batch process.

4

Points

Numeric value

7

It shows the points retained by the members.
Initial value is 0.

Since header records and footer records are not being handled in this tutorial, refer File access for handling of header and footer record and file formats.

Job overview

Process flow and process sequence are shown below to understand the overview of the job which inputs or outputs data by accessing file created here.

The process sequence mentions the scope of transaction control, however, the operation is achieved by performing pseudo transaction control in case of a file. For details, refer to Supplement for non-transactional data sources.

Process flow overview

Process flow overview is shown below.

ProcessFlow of FileAccess Job
Process flow for file access job
Process sequence in case of a chunk model

Process sequence in case of a chunk model is explained.

Orange object represents a class to be implemented this time.

ProcessSequence of FileAccess Job by ChunkModel
Sequence diagram of chunk model
Explanation of sequence diagram
  1. A step is executed from the job.

  2. Step opens the input resource.

  3. FlatFileItemReader opens member_info(input) file.

  4. Step opens an output resource.

  5. FlatFileItemWriter opens member_info(output) file.

    • Repeat process from steps 6 to 16 until input data gets exhausted.

    • Start a framework transaction (pseudo) in chunk units.

    • Repeat process from steps 6 to 12 until a chunk size is achieved.

  6. Step fetches 1 record of input data from FlatFileItemReader.

  7. FlatFileItemReader fetches 1 record of input data from member_info(input) file.

  8. member_info(input) file returns input data to FlatFileItemReader.

  9. FlatFileItemReader returns input data to step.

  10. Step performs a process for input data by PointAddItemProcessor.

  11. PointAddItemProcessor reads input data and adds points.

  12. PointAddItemProcessor returns process results to the step.

  13. Step outputs chunk size data by FlatFileItemWriter.

  14. FlatFileItemWriter buffers process results.

  15. Step commits framework transaction (pseudo).

  16. FlatFileItemWriter performs data flush and writes data in the buffer to member_info(output) file.

  17. Step closes the input resource.

  18. FlatFileItemReader closes member_info(input) file.

  19. Step closes output resource.

  20. FlatFileItemWriter closes member_info(output) file.

  21. Step returns the exit code (here, successful completion: 0) to job.

Process sequence in case of a tasklet model

Process sequence in case of a tasklet model is explained.

Orange object represents a class to be implemented this time.

ProcessSequence of FileAccess Job by TaskletModel
Sequence diagram of tasklet model
Explanation of sequence diagram
  1. Step is executed from the job.

    • Step starts a framework transaction (pseudo).

  2. Step executes PointAddTasklet.

  3. PointAddTasklet opens an input resource.

  4. FlatFileItemReader opens a member_info(input) file.

  5. PointAddTasklet opens an output resource.

  6. FlatFileItemWriter opens a member_info(output) file.

    • Repeat the process from steps 7 to 13 until the input data gets exhausted.

    • Repeat the process from steps 7 to 11 until a certain number of records is reached.

  7. PointAddTasklet fetches 1 record of input data from FlatFileItemReader.

  8. FlatFileItemReader fetches 1 record of input data from member_info(input) file.

  9. member_info(input) file returns input data to FlatFileItemReader.

  10. FlatFileItemReader returns input data to tasklet.

  11. PointAddTasklet reads input data and adds points.

  12. PointAddTasklet outputs a certain number of records by FlatFileItemWriter.

  13. FlatFileItemWriter buffers the process results.

  14. PointAddTasklet closes the input resource.

  15. FlatFileItemReader closes member_info(input) file.

  16. PointAddTasklet closes output resource.

  17. PointAddTasklet returns termination of process to step.

  18. Step commits framework transaction (pseudo).

  19. FlatFileItemWriter performs data flush and write the data in the buffer to member_info(output) file.

  20. FlatFileItemWriter closes member_info(output) file.

  21. Step returns exit code (here, successful completion:0).

How to implement a chunk model and a tasklet model respectively is explained subsequently.

Implementation in chunk model

Creation of a job which inputs or outputs data by accessing a file in chunk model, till execution of job are implemented by following procedure.

Creating a job Bean definition file

In Bean definition file, configure a way to combine elements which constitute a job that inputs/outputs data by accessing a file in chunk model.
In this example, only the frame and common settings of Bean definition file are described and each component is configured in the subsequent sections.

src/main/resources/META-INF/jobs/fileaccess/jobPointAddChunk.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:batch="http://www.springframework.org/schema/batch"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
             http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
             http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <!-- (1) -->
    <import resource="classpath:META-INF/spring/job-base-context.xml"/>

    <!-- (2) -->
    <context:component-scan base-package="org.terasoluna.batch.tutorial.fileaccess.chunk"/>

</beans>
Explanation
Sr. No. Explanation

(1)

Import a configuration that always reads required Bean definition while using TERASOLUNA Batch 5.x.

(2)

Configure the base package to be subjected for the component scanning.
Specify a package wherein a component to be used (implementation class of ItemProcessor etc) is stored, in base-package attribute.

DTO implementation

Implement DTO class as a class to retain business data.
Create DTO class for each file.

Since it is used in common for chunk model / tasklet model, it can be skipped if it is created already.

Implement DTO class as a class for conversion, as shown below.

org.terasoluna.batch.tutorial.common.dto.MemberInfoDTO
package org.terasoluna.batch.tutorial.common.dto;

public class MemberInfoDto {
    private String id; // (1)

    private String type; // (2)

    private String status; // (3)

    private int point; // (4)

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public int getPoint() {
        return point;
    }

    public void setPoint(int point) {
        this.point = point;
    }
}
Explanation
Sr. No. Explanation

(1)

Define id as a field that corresponds to member ID.

(2)

Define type as a field that corresponds to membership type.

(3)

Define status as a field that corresponds to product purchasing flag.

Defining file access

Configure a job Bean definition file in order to input/output data by accessing a file.

Add following (1) and subsequent details to job Bean definition file as a setting of ItemReader and ItemWriter.
For the configuration details not covered here, refer Variable length record input and Variable length record output.

src/main/resources/META-INF/jobs/fileaccess/jobPointAddChunk.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:batch="http://www.springframework.org/schema/batch"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
             http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
             http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <import resource="classpath:META-INF/spring/job-base-context.xml"/>

    <context:component-scan base-package="org.terasoluna.batch.tutorial.fileaccess.chunk"/>

    <!-- (1) (2) -->
    <bean id="reader"
          class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
          p:resource="file:#{jobParameters['inputFile']}"
          p:encoding="UTF-8"
          p:strict="true">
        <property name="lineMapper">
            <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
                <property name="lineTokenizer"> <!-- (3) -->
                    <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
                          p:names="id,type,status,point"
                          p:delimiter=","
                          p:quoteCharacter='"'/> <!-- (4) (5) -->
                </property>
                <property name="fieldSetMapper"> <!-- (6) -->
                    <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
                          p:targetType="org.terasoluna.batch.tutorial.common.dto.MemberInfoDto"/>
                </property>
            </bean>
        </property>
    </bean>

    <!-- (7) (8) -->
    <bean id="writer"
          class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
          p:resource="file:#{jobParameters['outputFile']}"
          p:encoding="UTF-8"
          p:lineSeparator="&#x0A;"
          p:appendAllowed="false"
          p:shouldDeleteIfExists="true"
          p:transactional="true">
        <property name="lineAggregator"> <!-- (9) -->
            <bean class="org.springframework.batch.item.file.transform.DelimitedLineAggregator"
                  p:delimiter=","> <!-- (10) -->
                <property name="fieldExtractor"> <!-- (11) -->
                    <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
                          p:names="id,type,status,point"/> <!-- (12) -->
                </property>
            </bean>
        </property>
    </bean>

</beans>
Explanation
Sr. No. Explanation

(1)

Configure ItemReader.
Specify org.springframework.batch.item.file.FlatFileItemReader which is an implementation class of ItemReader in class attribute, in order to read flat file offered by Spring Batch.
Specify step scope in scope attribute.

(2)

Specify path of input file in resource attribute.
Although the path can be specified directly, the parameter name of input file path is specified here in order to pass it by parameter at the time of starting the job.

(3)

Configure lineTokenizer.
Specify org.springframework.batch.item.file.transform.DelimitedLineTokenizer - an implementation class of LineTokenizer in class attribute, which divides the records by specifying a delimiter offered by Spring Batch.
It supports reading of escaped line feed character, delimiter and enclosed character, defined in the specifications of RFC-4180 which is considered as a general CSV format.

(4)

Set the name to be assigned to each field of 1 record, in names attribute.
Each field can be retrieved by using the name set in FieldSet used in FieldSetMapper.
Specify each name with a comma delimiter from the beginning of the record.

(5)

Specify the comma as a delimiter in delimiter attribute.

(6)

Set fieldSetMapper.
Since special conversions like character strings and numbers are not required at the moment, specify org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper, in class attribute.
Specify DTO class created by DTO implementation as a class for conversion, in targetType attribute. Accordingly, an instance is generated wherein a value is automatically set in the field that matches with name of each field set in (4).

(7)

Set ItemWriter.
Specify org.springframework.batch.item.file.FlatFileItemWriter - an implementation class of ItemWriter, in class attribute in order to write to the flat file offered by Spring Batch.
Specify step scope in the scope attribute.
In this tutorial, set appendAllowed attribute to false(do not write) and shouldDeleteIfExists attribute to true(delete existing file) and ensure to create a new file no matter how many times a job is to be executed.
Enable pseudo transaction control by specifying transactional attribute to true.

(8)

Set path of output file in resource attribute.
Parameter name of output file path is specified so that it can be passed by parameter at the start of the job.

(9)

Set lineAggregator.
Specify org.springframework.batch.item.file.transform.LineAggregator to map the target Bean in 1 record, in class attribute.
Map the property of the Bean and each field in the record by FieldExtractor.

(10)

Specify the comma as a delimiter, in delimiter attribute.

(11)

Set fieldExtractor.
Map the value that matches with the field of DTO class specified in (6) to the name of each field to be specified in (12).
Specify org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor in class attribute.

(12)

Specify the name assigned to each field of 1 record, in names attribute.

Implementation of logic

Implement business logic class which adds the points.

Implement following operations.

Implementation of PointAddItemProcessor class

Implement PointAddItemProcessor class which implements ItemProcessor interface.

org.terasoluna.batch.tutorial.fileaccess.chunk.PointAddItemProcessor
package org.terasoluna.batch.tutorial.fileaccess.chunk;

import org.springframework.batch.item.ItemProcessor;
import org.springframework.stereotype.Component;
import org.terasoluna.batch.tutorial.common.dto.MemberInfoDto;

@Component // (1)
public class PointAddItemProcessor implements ItemProcessor<MemberInfoDto, MemberInfoDto> { // (2)

    private static final String TARGET_STATUS = "1"; // (3)

    private static final String INITIAL_STATUS = "0"; // (4)

    private static final String GOLD_MEMBER = "G"; // (5)

    private static final String NORMAL_MEMBER = "N"; // (6)

    private static final int MAX_POINT = 1000000; // (7)

    @Override
    public MemberInfoDto process(MemberInfoDto item) throws Exception { // (8) (9) (10)
        if (TARGET_STATUS.equals(item.getStatus())) {
            if (GOLD_MEMBER.equals(item.getType())) {
                item.setPoint(item.getPoint() + 100);
            } else if (NORMAL_MEMBER.equals(item.getType())) {
                item.setPoint(item.getPoint() + 10);
            }

            if (item.getPoint() > MAX_POINT) {
                item.setPoint(MAX_POINT);
            }

            item.setStatus(INITIAL_STATUS);
        }

        return item;
    }
}
Explanation
Sr. No. Explanation

(1)

Define a Bean by assigning @Component annotation so as to subject it to component scanning.

(2)

Implement ItemProcessor interface which specifies the type of object used for input/output, in respective type argument.
Specify MemberInfoDTO created by both DTO implementation for the objects used in input/output here.

(3)

Define a product purchasing flag:1 for the addition of points, as a constant
Essentially, these field constants are defined in constant classes and are not defined in the logic. It should be noted that it is defined as a constant for the sake of convenience, in this tutorial. (Same applies to following constants)

(4)

Define initial value of product purchasing flag:0 as a constant.

(5)

Define membership type:G (gold member), as a constant.

(6)

Define membership type:N (normal member),as a constant.

(7)

Define the upper limit value of points:1000000, as a constant.

(8)

Implement product purchasing flag and, business logic to add points according to membership type.

(9)

Type of return value is MemberInfoDTO - a type of output object specified by the type argument of ItemProcessor interface implemented by this class.

(10)

Type of item received as an argument is MemberInfoDTO - a type of input object specified by type argument of ItemProcessor interface implemented by this class.

Configuring Job Bean definition file

Add following (1) and subsequent objects to job Bean definition file in order to set the created business logic as a job.

src/main/resources/META-INF/jobs/fileaccess/jobPointAddChunk.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:batch="http://www.springframework.org/schema/batch"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
             http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
             http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <import resource="classpath:META-INF/spring/job-base-context.xml"/>

    <context:component-scan base-package="org.terasoluna.batch.tutorial.fileaccess.chunk"/>

    <bean id="reader"
          class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
          p:resource="file:#{jobParameters['inputFile']}"
          p:encoding="UTF-8"
          p:strict="true">
        <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="id,type,status,point"
                          p:delimiter=","
                          p:quoteCharacter='"'/>
                </property>
                <property name="fieldSetMapper">
                    <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
                          p:targetType="org.terasoluna.batch.tutorial.common.dto.MemberInfoDto"/>
                </property>
            </bean>
        </property>
    </bean>

    <bean id="writer"
          class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
          p:resource="file:#{jobParameters['outputFile']}"
          p:encoding="UTF-8"
          p:lineSeparator="&#x0A;"
          p:appendAllowed="false"
          p:shouldDeleteIfExists="true"
          p:transactional="true">
        <property name="lineAggregator">
            <bean class="org.springframework.batch.item.file.transform.DelimitedLineAggregator"
                  p:delimiter=",">
                <property name="fieldExtractor">
                    <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
                          p:names="id,type,status,point"/>
                </property>
            </bean>
        </property>
    </bean>

    <!-- (1) -->
    <batch:job id="jobPointAddChunk" job-repository="jobRepository">
        <batch:step id="jobPointAddChunk.step01"> <!-- (2) -->
            <batch:tasklet transaction-manager="jobTransactionManager">
                <batch:chunk reader="reader"
                             processor="pointAddItemProcessor"
                             writer="writer" commit-interval="10"/> <!-- (3) -->
            </batch:tasklet>
        </batch:step>
    </batch:job>
</beans>
Explanation
Sr. No. Explanation

(1)

Set the job.
id attribute must be unique within the range of all jobs included in 1 batch application.
Here, specify jobPointAddChunk as a job name of chunk model.

(2)

Configure step.
Although it is not necessary to have a id attribute unique within the range of all jobs included in 1 batch application, it should be taken as unique to enable easy tracking at the time of failure.
The format consists of [step + serial number] for the id attribute specified in (1) unless there is a specific reason.
Here, specify jobPointAddChunk.step01 as a step name for chunk model job.

(3)

Configure chunk model job.
Specify Bean ID of ItemReader and ItemWriter defined in the previous section, in respective reader and writer attributes.
Specify pointAddItemProcessor - a Bean ID of implementation class of ItemProcessor, in processor attribute.
Set 10 as input data count per chunk, in commit-interval attribute.

Tuning of commit-interval

commit-interval is a tuning point for performance in the chunk model job.

In this tutorial, it is set to 10, however the appropriate number varies depending on available machine resources and job characteristics. In case of the jobs which access multiple resources and process the data, process throughput can reach to 100 records from 10 records. On the other hand, when input and output resources are in 1:1 ratio and there are enough jobs to transfer data, process throughout can reach to 5,000 cases or 10,000 cases.

It is preferable to temporarily place commit-interval at the time of 100 records while starting a job and then tune for each job according to performance measurement results implemented subsequently.

Job execution

Execute the created job on IDE and verify the results.

Executing job from execution configuration

Create execution configuration as below and execute job.
For how to create execution configuration, refer Operation check.

Here, the job is executed by using normal system data.
Parameters of input and output file are added to Arguments tab as arguments.

Execution configuration setting value
  • Name: Any name (Example: Run FileAccessJob for ChunkModel)

  • Main tab

    • Project: terasoluna-batch-tutorial

    • Main class: org.springframework.batch.core.launch.support.CommandLineJobRunner

  • Arguments tab

    • Program arguments: META-INF/jobs/fileaccess/jobPointAddChunk.xml jobPointAddChunk inputFile=files/input/input-member-info-data.csv outputFile=files/output/output-member-info-data.csv

Verifying console log

Verify that the log with following details is output to Console.

Example of console log output
[2017/08/18 11:09:19] [main] [o.s.b.c.l.s.SimpleJobLauncher] [INFO ] Job: [FlowJob: [name=jobPointAddChunk]] completed with the following parameters: [{inputFile=files/input/input-member-info-data.csv, outputFile=files/output/output-member-info-data.csv, jsr_batch_run_id=386}] and the following status: [COMPLETED]
[2017/08/18 11:09:19] [main] [o.s.c.s.ClassPathXmlApplicationContext] [INFO ] Closing org.springframework.context.support.ClassPathXmlApplicationContext@735f7ae5: startup date [Fri Aug 18 11:09:12 JST 2017]; root of context hierarchy

Verifying exit code

Verify that the process is executed successfully by using exit codes.
For verification procedure, refer Job execution and results verification. Verify that the exit code (exit value) is 0 (successful termination).

Confirm the Exit Code of FileAccess for ChunkModel
Verifying exit codes

Verifying member information file

Compare input and output contents of member information file and verify that they are in accordance with the verification details.

Verification details
  • Member information file should be output in the output directory

    • Output file: files/output/output-member-info-data.csv

  • status field

    • Records with value "0"(initial status) should not exist

  • point field

    • Points should be added according to membership type, for point addition

      • 100 points when the type field is "G"(gold member)

      • 10 points when the type field is "N"(normal member)

    • Records with points exceeding 1,000,000 points (upper limit) should not exist

The input/output details of member information file are as follows.
The file fields are displayed in the sequence of id(Member id), type(Membership type), status(Product purchasing flag) and point(Points).

File of member_info
Input/output details of member information file

Implementation in tasklet model

Implement the procedure from creation to execution of job which inputs and outputs data by accessing a file in tasklet model.

Creating job Bean definition file

How to combine elements which constitute a job performing data input and output by accessing a file in Tasklet model, is configured in Bean definition file.
Here, only frame and common settings of Bean definition file are described, and set each configuration element in the following sections

src/main/resources/META-INF/jobs/fileaccess/jobPointAddTasklet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:batch="http://www.springframework.org/schema/batch"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
             http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
             http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <!-- (1) -->
    <import resource="classpath:META-INF/spring/job-base-context.xml"/>

    <!-- (2) -->
    <context:component-scan base-package="org.terasoluna.batch.tutorial.fileaccess.tasklet"/>

</beans>
Explanation
Sr. No. Explanation

(1)

Always import settings for reading required Bean definition while using TERASOLUNA Batch 5.x.

(2)

Specify a package which stores the components to be used (implementation class of Tasklet etc), in base-package attribute.

Implementation of DTO

Implement a DTO class as a class to retain business data.
Create a DTO class for each file.

Since it is used as a common in chunk model / tasklet model, it can be skipped if created already.

Implement DTO class as a class for conversion as shown below.

org.terasoluna.batch.tutorial.common.dto.MemberInfoDTO
package org.terasoluna.batch.tutorial.common.dto;

public class MemberInfoDto {
    private String id; // (1)

    private String type; // (2)

    private String status; // (3)

    private int point; // (4)

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public int getPoint() {
        return point;
    }

    public void setPoint(int point) {
        this.point = point;
    }
}
Explanation
Sr. No. Explanation

(1)

Define id as a field corresponding to member id.

(2)

Define type as a field corresponding to membership type.

(3)

Define status as a field corresponding product purchasing flag.

(4)

Define point as a field corresponding to points.

Defining file access

Configure a job Bean definition file to input and output data by accessing a file.

Add following (1) and subsequent objects to job Bean definition file as a setting of ItemReader and ItemWriter.
For the setting details not covered here, refer Variable length record input and Variable length record output.

src/main/resources/META-INF/jobs/fileaccess/jobPointAddTasklet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:batch="http://www.springframework.org/schema/batch"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
             http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
             http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <import resource="classpath:META-INF/spring/job-base-context.xml"/>

    <context:component-scan base-package="org.terasoluna.batch.tutorial.fileaccess.chunk"/>

    <!-- (1) (2) -->
    <bean id="reader"
          class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
          p:resource="file:#{jobParameters['inputFile']}"
          p:encoding="UTF-8"
          p:strict="true">
        <property name="lineMapper">
            <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
                <property name="lineTokenizer"> <!-- (3) -->
                    <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"
                          p:names="id,type,status,point"
                          p:delimiter=","
                          p:quoteCharacter='"'/> <!-- (4) (5) -->
                </property>
                <property name="fieldSetMapper"> <!-- (6) -->
                    <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
                          p:targetType="org.terasoluna.batch.tutorial.common.dto.MemberInfoDto"/>
                </property>
            </bean>
        </property>
    </bean>

    <!-- (7) (8) -->
    <bean id="writer"
          class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
          p:resource="file:#{jobParameters['outputFile']}"
          p:encoding="UTF-8"
          p:lineSeparator="&#x0A;"
          p:appendAllowed="false"
          p:shouldDeleteIfExists="true"
          p:transactional="true">
        <property name="lineAggregator"> <!-- (9) -->
            <bean class="org.springframework.batch.item.file.transform.DelimitedLineAggregator"
                  p:delimiter=","> <!-- (10) -->
                <property name="fieldExtractor"> <!-- (11) -->
                    <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
                          p:names="id,type,status,point"/> <!-- (12) -->
                </property>
            </bean>
        </property>
    </bean>

</beans>
Explanation
Sr. No. Explanation

(1)

Configure ItemReader.
Specify org.springframework.batch.item.file.FlatFileItemReader - an implementation class of ItemReader to read flat file provided by Spring Batch, in class attribute.
Specify step scope in scope attribute.

(2)

Specify path of input file in resource attribute.
Although the path can also be specified directly, a parameter name of input file path is specified here in order to pass it as a parameter at the time of starting the job.

(3)

Configure lineTokenizer.
Specify org.springframework.batch.item.file.transform.DelimitedLineTokenizer - an implementation class of LineTokenizer, in class attribute which splits the records by specifying a delimiter provided by Spring Batch.
It handles reading of escaped newline character, delimiter and enclosed character, defined in specifications of RFC-4180 which is considered as a general CSV format.

(4)

Set the name assigned to each field of 1 record, in names attribute.
Each item can be retrieved by using the name set in FieldSet which is used in FieldSetMapper.
Specify each name with a comma separator from the beginning of record.

(5)

Specify a comma as a delimiter, in delimiter attribute.

(6)

Set fieldSetMapper.
Specify org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper, in class attribute since special conversion process like character string or numerals is not required here.
Specify a DTO class created in Implementation of DTO as a class for conversion, in targetType attribute. Accordingly, an instance is generated by automatically setting a value in a field that matches the name of each item set in (4).

(7)

Set ItemWriter.
Specify org.springframework.batch.item.file.FlatFileItemWriter - an implementation class of ItemWriter, in class attribute in order to write to a flat file offered by Spring Batch.
Specify step scope, in scope attribute.
In this tutorial, appendAllowed attribute is set to false(do not add) and shouldDeleteIfExists attribute is set to true(delete existing file) and it is ensured that a new file is created no matter how many times a job is executed.
Specify true in transactional attribute, and enable pseudo transaction control.

(8)

Set path of output file in resource attribute.
A parameter name of output file path is specified in order to pass it as a parameter at the time of starting a job.

(9)

Set lineAggregator.
Specify org.springframework.batch.item.file.transform.LineAggregator, in class attribute in order to map target Bean to 1 record.
Map properties of the Bean and each item in the record by FieldExtractor.

(10)

Specify a comma as a delimiter, in delimiter attribute.

(11)

Set fieldExtractor.
Map the value that matches with the field of DTO class specified in (6) with the name of each field to be specified in (12).
Specify org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor, in class attribute.

(12)

Set the name assigned to each item of 1 record, in names attribute same as (4).

Implementation of Tasklet which use chunk model components

In this tutorial, ItemReader.ItemWriter which are components of chunk model are used in order to easily create a job which accesses a file in the chunk model.

Refer Tasklet implementation using components of chunk model and determine appropriately for whether to use various components of chunk model during Tasklet implementation.

Implementation of logic

Implement a business logic class which adds the points.

Implement following operations.

Implementation of PointAddTasklet class

Create PointAddTasklet class which implements Tasklet interface.

org.terasoluna.batch.tutorial.fileaccess.tasklet.PointAddTasklet
package org.terasoluna.batch.tutorial.fileaccess.tasklet;

import org.springframework.batch.core.StepContribution;
import org.springframework.batch.core.scope.context.ChunkContext;
import org.springframework.batch.core.step.tasklet.Tasklet;
import org.springframework.batch.item.ItemStreamException;
import org.springframework.batch.item.ItemStreamReader;
import org.springframework.batch.item.ItemStreamWriter;
import org.springframework.batch.repeat.RepeatStatus;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
import org.terasoluna.batch.tutorial.common.dto.MemberInfoDto;

import javax.inject.Inject;
import java.util.ArrayList;
import java.util.List;

@Component // (1)
@Scope("step") // (2)
public class PointAddTasklet implements Tasklet {

    private static final String TARGET_STATUS = "1"; // (3)

    private static final String INITIAL_STATUS = "0"; // (4)

    private static final String GOLD_MEMBER = "G"; // (5)

    private static final String NORMAL_MEMBER = "N"; // (6)

    private static final int MAX_POINT = 1000000; // (7)

    private static final int CHUNK_SIZE = 10; // (8)

    @Inject // (9)
    ItemStreamReader<MemberInfoDto> reader; // (10)

    @Inject // (9)
    ItemStreamWriter<MemberInfoDto> writer; // (11)

    @Override
    public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception { // (12)
        MemberInfoDto item = null;

        List<MemberInfoDto> items = new ArrayList<>(CHUNK_SIZE); // (13)
        try {

            reader.open(chunkContext.getStepContext().getStepExecution().getExecutionContext()); // (14)
            writer.open(chunkContext.getStepContext().getStepExecution().getExecutionContext()); // (14)

            while ((item = reader.read()) != null) { // (15)

                if (TARGET_STATUS.equals(item.getStatus())) {
                    if (GOLD_MEMBER.equals(item.getType())) {
                        item.setPoint(item.getPoint() + 100);
                    } else if (NORMAL_MEMBER.equals(item.getType())) {
                        item.setPoint(item.getPoint() + 10);
                    }

                    if (item.getPoint() > MAX_POINT) {
                        item.setPoint(MAX_POINT);
                    }

                    item.setStatus(INITIAL_STATUS);
                }

                items.add(item);

                if (items.size() == CHUNK_SIZE) { // (16)
                    writer.write(items); // (17)
                    items.clear();
                }
            }

            writer.write(items); // (18)
        } finally {
            try {
                reader.close(); // (19)
            } catch (ItemStreamException e) {
                // do nothing.
            }
            try {
                writer.close(); // (19)
            } catch (ItemStreamException e) {
                // do nothing.
            }
        }

        return RepeatStatus.FINISHED; // (20)
    }
}
Explanation
Sr. No. Explanation

(1)

Assign @Component annotation and define a Bean for subjecting it to component scanning.

(2)

Assign @Scope annotation to the class and specify step scope.

(3)

Define product purchasing flag:1 for point addition, as a constant.
Originally, such a field constant is defined in a constant class, and it is very rarely defined in the logic. In this tutorial, it is considered to be defined as a constant, for the sake of convenience (same is applicable to subsequent constants)

(4)

Define initial value:0 for product purchasing flag, as a constant.

(5)

Define membership type: G (gold member), as a constant.

(6)

Define membership type: N (Normal member),as a constant.

(7)

Define upper limit value: 1000000, as a constant.

(8)

Define unit to be processed together (fixed number): 10, as a constant.

(9)

Assign @Inject annotation and inject implementation of ItemStreamReader/ItemStreamWriter.

(10)

Define type as ItemStreamReader - sub-interface of ItemReader to access the file.
ItemStreamReader is required to open/close a resource.

(11)

Define type as ItemStreamWriter - sub-interface of ItemWriter to access the file.
ItemStreamWriter is required to open/close the resource.

(12)

Implement a product purchasing flag, and business logic to add points according to membership type.

(13)

Define a list to store a fixed number of item.

(14)

Open input and output resource.

(15)

Perform a loop through all input resources
ItemReader#read returns null when all the input data reaches end of reading.

(16)

Determine whether number of item added to the list has reached a fixed number.
When it reaches a certain number, output to the file in (17) and clear the list.

(17)

Output processed data to the file.

(18)

Output overall process records/remaining balance records.

(19)

Close input and output resource.

(20)

Return whether Tasklet process has been completed.
Always specify return RepeatStatus.FINISHED;.

Configuring job Bean definition file

Add following (1) and subsequent details to job Bean definition file in order to configure the created business logic as a job.

src/main/resources/META-INF/jobs/fileaccess/jobPointAddTasklet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:batch="http://www.springframework.org/schema/batch"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
             http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
             http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <import resource="classpath:META-INF/spring/job-base-context.xml"/>

    <context:component-scan base-package="org.terasoluna.batch.tutorial.fileaccess.tasklet"/>

    <bean id="reader"
          class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"
          p:resource="file:#{jobParameters['inputFile']}"
          p:encoding="UTF-8"
          p:strict="true">
        <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="id,type,status,point"
                          p:delimiter=","
                          p:quoteCharacter='"'/>
                </property>
                <property name="fieldSetMapper">
                    <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"
                          p:targetType="org.terasoluna.batch.tutorial.common.dto.MemberInfoDto"/>
                </property>
            </bean>
        </property>
    </bean>

    <bean id="writer"
          class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"
          p:resource="file:#{jobParameters['outputFile']}"
          p:encoding="UTF-8"
          p:lineSeparator="&#x0A;"
          p:appendAllowed="false"
          p:shouldDeleteIfExists="true"
          p:transactional="true">
        <property name="lineAggregator">
            <bean class="org.springframework.batch.item.file.transform.DelimitedLineAggregator"
                  p:delimiter=",">
                <property name="fieldExtractor">
                    <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"
                          p:names="id,type,status,point"/>
                </property>
            </bean>
        </property>
    </bean>

    <!-- (1) -->
    <batch:job id="jobPointAddTasklet" job-repository="jobRepository">
        <batch:step id="jobPointAddTasklet.step01"> <!-- (2) -->
            <batch:tasklet transaction-manager="jobTransactionManager"
                           ref="pointAddTasklet"/> <!-- (3) -->
        </batch:step>
    </batch:job>
</beans>
Explanation
Sr. No. Explanation

(1)

Configure job.
id attribute must be unique within the scope of all jobs included in 1 batch application.
Here, specify jobPointAddTasklet as a job name of tasklet model.

(2)

Configure step.
id attribute is not required to be unique within the scope of all the jobs included in 1 batch application, however a unique attribute is used since it helps in easy tracking at the time of failure.
[step+Sr.No.] is added to id attribute specified in (1) unless there is a specific reason otherwise.
Here, specify jobPointAddTasklet.step01 as a step name of tasklet model job.

(3)

Configure tasklet.
Specify pointAddTasklet - a Bean ID of implementation class of Tasklet in ref attribute.

Job executio

Execute created job on IDE and verify results.

Execute job from execution configuration

Create execution configuration as shown below and execute job.
For how to create execution configuration, refer Operation check.

Here, execute job by using normal data system.
Add parameters of input and output file to Arguments tab, as arguments.

Setup value of execution configuration
  • Name: Any name (Example: Run FileAccessJob for TaskletModel)

  • Main tab

    • Project: terasoluna-batch-tutorial

    • Main class: org.springframework.batch.core.launch.support.CommandLineJobRunner

  • Arguments tab

    • Program arguments: META-INF/jobs/fileaccess/jobPointAddTasklet.xml jobPointAddTasklet inputFile=files/input/input-member-info-data.csv outputFile=files/output/output-member-info-data.csv

Verifying console log

Verify that following log details are output in Console.

Output example of console log
[2017/09/12 10:13:18] [main] [o.s.b.c.l.s.SimpleJobLauncher] [INFO ] Job: [FlowJob: [name=jobPointAddTasklet]] completed with the following parameters: [{inputFile=files/input/input-member-info-data.csv, outputFile=files/output/output-member-info-data.csv, jsr_batch_run_id=474}] and the following status: [COMPLETED]
[2017/09/12 10:13:18] [main] [o.s.c.s.ClassPathXmlApplicationContext] [INFO ] Closing org.springframework.context.support.ClassPathXmlApplicationContext@735f7ae5: startup date [Tue Sep 12 10:13:16 JST 2017]; root of context hierarchy

Verifying exit codes

Verify that the process has terminated successfully using exit code.
For verification procedure, refer Job execution and results verification. Verify that the exit code (exit value) is 0 (successful termination).

Confirm the Exit Code of FileAccessJob for TaskletModel
Verifying exit codes

Verifying member information file

Compare input and output contents of member information and verify that the details are in accordance with the verification details.

Verification details
  • Member information file should output in the output directory

    • Output file: files/output/output-member-info-data.csv

  • status field

    • Records with value "0"(initial status) should not exist

  • point field

    • Points should be added according to membership type, for point addition

      • 100 points when type field is "G"(gold member)

      • 10 points when type field is "N"(normal member)

    • Points should not exceed 1,000,000 points(upper limit value)

The input/output details of member information file are as follows.
The file fields are displayed in the sequence of id(Member id), type(Membership type), status(Product purchasing flag) and point(Points).

File of member_info
Input/output details of member information file
TERASOLUNA Batch Framework for Java (5.x) Development Guideline - version 5.1.1.RELEASE, 2018-3-16