Batchlet Simple

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How to run the sample
The source code for this sample can be found in the javaee7-samples GitHub repository. The first thing we need to do is to get the source by downloading the repository and then go into the samples folder:
git clone git://github.com/javaee-samples/javaee7-samples.git
cd javaee7-samples/batch/batchlet-simple/
Now we are ready to start testing. You can run all the tests in this sample by executing:
mvn test
Or you can run individual tests by executing one of the following:
mvn test -Dtest=MyBatchletTest

Batchlet Simple - Execute a task oriented step

MyBatchletTest

Batchlet is the simplest processing style available in the Batch specification. It’s a task oriented step where the task is invoked once, executes, and returns an exit status.

A Batchlet need to implement Batchlet interface or in alternative extend AbstractBatchlet that already provides empty implementations for all methods.

@Named()
public class MyBatchlet extends AbstractBatchlet {

    public MyBatchlet();

    @Override()
    public String process();
}

We are mostly interested in overriding AbstractBatchlet#process to provide the behaviour that we want to achieve with the Batchlet itself. Common cases include: copy files to process with a chunk oriented step, startup and cleanup, or validations to your processing workflow.

To run your Batchlet, just add it to the job xml file (myJob.xml).

<?xml version="1.0" encoding="UTF-8"?>
<job id="myJob" xmlns="http://xmlns.jcp.org/xml/ns/javaee" version="1.0">
    <step id="myStep" >
        <batchlet ref="myBatchlet"/>
    </step>
</job>

We’re just going to deploy the application as a web archive. Note the inclusion of the following files:

/META-INF/batch-jobs/myJob.xml

The myJob.xml file is needed for running the batch definition.

@Deployment
public static WebArchive createDeployment() {
    WebArchive war = ShrinkWrap.create(WebArchive.class)
            .addClass(BatchTestHelper.class)
            .addClass(MyBatchlet.class)
            .addAsWebInfResource(EmptyAsset.INSTANCE, ArchivePaths.create("beans.xml"))
            .addAsResource("META-INF/batch-jobs/myJob.xml");
    System.out.println(war.toString(true));
    return war;
}

In the test, we’re just going to invoke the batch execution and wait for completion. To validate the test expected behaviour we just need to check the Batch Status in the JobExecution object. We should get a COMPLETED.

@Test
public void testBatchletProcess() throws Exception {
    JobOperator jobOperator = BatchRuntime.getJobOperator();
    Long executionId = jobOperator.start("myJob", new Properties());
    JobExecution jobExecution = jobOperator.getJobExecution(executionId);

    jobExecution = BatchTestHelper.keepTestAlive(jobExecution);

    (1)
    assertEquals(jobExecution.getBatchStatus(), BatchStatus.COMPLETED);
}
  1. Job should be completed.

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Recent Changelog

  • Dec 14, 2014: Switch from polling on jobexecution (for job completion) to polling with joboperator and executionid by Scott Kurz
  • Jul 05, 2014: Removed header license for batch xml files by Roberto Cortez
  • Jun 22, 2014: Removed header license. the licensing is now referenced in the license file in the root of the project by Roberto Cortez
  • Jun 20, 2014: Added fqn to java ee api references to generate direct links to javadocs by radcortez
  • Jun 19, 2014: Documentation clarifications and typos by radcortez
  • Jun 05, 2014: Add include of myjbos.xml file in doc by Aslak Knutsen
  • May 29, 2014: Added documentation to batchlet-simple project by Roberto Cortez
  • Dec 31, 2013: Code style issues by Roberto Cortez
  • Dec 31, 2013: Removed servlets and jsp's by Roberto Cortez
  • Nov 21, 2013: Removing some redundant elements by Arun Gupta
How to help improve this sample
The source code for this sample can be found in the javaee7-samples GitHub repository. The first thing you need to do is to get the source by downloading the repository and then go into the samples folder:
git clone git://github.com/javaee-samples/javaee7-samples.git
cd javaee7-samples/batch/batchlet-simple/

Do the changes as you see fit and send a pull request!

Good Luck!