Passing arguments from BatchJob to Tasklet in Spring Batch - spring

Question

To all Spring enthusiasts, here's a good challenge. Hope someone can crack it!!!
I use Spring to batch the extraction process. I have two classes 'ExtractBatchJob' and 'TaskletImpl'
public class ExtractBatchJob {
/** Logger for current class */
private static Log log = LogFactory.getLog(Extractor.class);
public static void main(String[] args)
throws IOrganizationServiceRetrieveMultipleOrganizationServiceFaultFaultFaultMessage,
IOException {
ApplicationContext context = new ClassPathXmlApplicationContext(
"/META-INF/cxf/batch-context.xml");
SpringBusFactory factory = new SpringBusFactory(context);
Bus bus = factory.createBus();
SpringBusFactory.setDefaultBus(bus);
IOrganizationService service = (IOrganizationService) factory
.getApplicationContext().getBean("service");
JobLauncher jobLauncher = (JobLauncher)context.getBean("jobLauncher");
Job job = (Job) context.getBean("firstBatchJob");
try {
JobExecution execution = jobLauncher.run(job, new JobParameters());
}catch (Exception e){
e.printStackTrace();
}
}
The second class TaskletImpl implements the Spring Tasklet interface.
public class TaskletImpl implements Tasklet {
/** Logger for current class */
private static Log log = LogFactory.getLog(CRMExtractor.class);
/* (non-Javadoc)
* #see org.springframework.batch.core.step.tasklet.Tasklet#execute(org.springframework.batch.core.StepContribution, org.springframework.batch.core.scope.context.ChunkContext)
*/
#Overridepublic RepeatStatus execute(StepContribution arg0, ChunkContext arg1)
throws Exception {
// TODO Auto-generated method stub
log.info("************ CRM Extraction Batch Job is executing!!! *******");
//QUESTION: To Extract Entity from third party
// web service need object reference for
//factory and service from ExtractBatchjob class
List<Entity> orderEntities = getEntities("orderQueryImpl", factory, service);
OrderDao orderDao = (OrderDao) factory.getApplicationContext()
.getBean("orderDao");
orderDao.batchInsert(orderEntities);*/
return RepeatStatus.FINISHED;
}
public static List<Entity> getEntities(String queryImpl, SpringBusFactory factory,
IOrganizationService service)
throws IOrganizationServiceRetrieveMultipleOrganizationServiceFaultFaultFaultMessage,
IOException {
QueryBuilder queryBuilder = (QueryBuilderTemplate) factory
.getApplicationContext().getBean(queryImpl);
QueryExpression queryExpr = queryBuilder.getQuery();
EntityCollection result = service
.retrieveMultiple(queryExpr);
return result.getEntities().getEntities();
}
}
Below is the snippet of the context file
`<import resource="cxf.xml" />
<bean id="firstBatch" class="com.abc.model.TaskletImpl" />
<batch:step id="firstBatchStepOne">
<batch:tasklet ref="firstBatch" />
</batch:step>
<batch:job id="firstBatchJob">
<batch:step id="stepOne" parent="firstBatchStepOne" />
</batch:job>`
My question is quite straightforward, how do I pass the two variables/objects 'service' and 'factory' to the TaskletImpl class from the ExtractBatchJob class.

Answer 1

The cleanest solution is to wire service and factory using Spring injection mechanism.
You have two solution:
Create SpringBusFactory as Spring bean and wire it into tasklet
Define a ContextBean (as singleton) for you job, create SpringBusFactory and set it as property of ContextBean; wire this bean to your tasklet
If you want to use object created outside Spring context (with new I meant) must be injected into Spring context.