Java EE 7 SDK

The Payroll Batch Sample Application

This sample demonstrates how to use the javax.batch.operations.JobOperator interface to submit batch jobs.

Description

This sample application demonstrates how to use the Batch Processing API (JSR 352) to submit batch jobs. A batch job is typically a long-running process that involves a sequence of steps. This sample processes a simple payroll by submitting a payroll job to the batch runtime using the JobOperator.start() method. This sample also demonstrates how to use the ItemReader, ItemProcessor, and ItemWriter interfaces.

The sample contains a singleton EJB that holds payroll records for a set of employees for three months. The singleton bean also holds the processed payroll records.

The job XML file for this sample specifies the process step with three batch artifacts:

SimpleItemReader is an ItemReader implementation that reads input records. The batch runtime calls the ItemReader.readItem() method to read input records. ItemReader implementations can read input records from a variety of sources like databases, text files, other Java EE components, etc. The batch runtime hands each record read in an ItemReader to an ItemProcessor.
In this sample, SimpleItemReader reads PayrollInputRecord objects from a singleton bean.
SimpleItemProcessor is an ItemProcessor implementation that processes an input record and returns an output record. The batch runtime calls the ItemProcessor.processItem() method to process the records from the ItemReader.
In this sample, SimpleItemProcessor receives PayrollInputRecord objects from the batch runtime, computes the net pay, and returns a PayrollRecord to the batch runtime. The batch runtime then uses an ItemWriter to store the results.
SimpleItemWriter is an ItemWriter implementation that writes the output record to some data storage resource such as a database, a text file, or another Java EE component. The batch runtime calls the ItemWriter.writeItems() method to write the records processed by the ItemWriter.
In this sample, SimpleItemWriter stores the processed PayrollRecord objects in a singleton bean.

This sample application uses the embedded JavaDB database service included with the Glassfish server.

The following is a list of servlets included in this sample:

URI pattern	Description
`/payroll/JobSubmitterServlet`	Displays payroll input records and allows starting a payroll processing job.

The application is built and deployed as a WAR file.

Key Features

This sample application demonstrates the following key features:

Defining a batch job using a job XML file. The batch job processes payroll records.
Using the ItemReader, ItemProcessor, and ItemWriter interfaces describe the logic of a steps in the payroll job.
Injecting EJBs and JobContext into implementations of the ItemReader and ItemWriter interfaces.
Using the JobOperator.start() method to start a batch job.

Building, Deploying, and Running the Application

Perform the following steps to build, deploy, and run the application:

Set up your build environment and configure the application server with which the build system has to work by following the common build instructions.
samples_install_dir is the sample application base directory. Go to: samples_install_dir/javaee7/batch/payroll.
Build the sample application by running the mvn package command from a command line terminal.
Deploy the sample application by running the asadmin deploy --force target/payroll.war command from a command line terminal.
The front page of this sample is at http://localhost:8080/payroll/JobSubmitterServlet.
(The port number might vary.)
Use the mvn clean command from a command line terminal to clean up the target directory.
Undeploy the sample application by running the asadmin undeploy payroll command from a command line terminal.

Troubleshooting

If you have problems when running the application, refer to the troubleshooting document.