Running a job

The entrance to executing a JSR-352 based job is through the javax.batch.operations.JobOperator. Spring Batch provides our own implementation to this interface (org.springframework.batch.core.jsr.launch.JsrJobOperator). This implementation is loaded via the javax.batch.runtime.BatchRuntime. Launching a JSR-352 based batch job is implemented as follows:

JobOperator jobOperator = BatchRuntime.getJobOperator();
long jobExecutionId = jobOperator.start("fooJob", new Properties());

The above code does the following:

  • Bootstraps a base ApplicationContext - In order to provide batch functionality, the framework needs some infrastructure bootstrapped. This occurs once per JVM. The components that are bootstrapped are similar to those provided by @EnableBatchProcessing. Specific details can be found in the javadoc for the JsrJobOperator.

  • Loads an ApplicationContext for the job requested - In the example above, the framework will look in /META-INF/batch-jobs for a file named fooJob.xml and load a context that is a child of the shared context mentioned previously.

  • Launch the job - The job defined within the context will be executed asynchronously. The JobExecution's id will be returned.

[Note]Note

All JSR-352 based batch jobs are executed asynchronously.

When JobOperator#start is called using SimpleJobOperator, Spring Batch determines if the call is an initial run or a retry of a previously executed run. Using the JSR-352 based JobOpeator#start(String jobXMLName, Properties jobParameters), the framework will always create a new JobInstance (JSR-352 job parameters are non-identifying). In order to restart a job, a call to JobOperator#restart(long executionId, Properties restartParameters) is required.