Question

The below is my requirement.

1. There is a screen in which an user enters a file name and clicks on submit.

2. On click of submit , a spring batch job must be triggered. The batch job reads the file and populates a database.

How do we call a spring batch job from a java code(specifically from a struts action class code ) ?

Also,I need to pass the file name(that the user entered on the screen) to the batch program. How do we achieve this ?

Answer 1

JobLauncher

Spring Batch jobs are launched (e.g. run) via a JobLauncher. One of the implementations of the launcher is provided by the framework that you can use outside of the box: SimpleJobLauncher. Take a look at the Configuring a JobLauncher section of the docs

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Running Jobs from within a Web Container

While most of the time batch jobs are launched from a command line ( scheduled or not ), there are several ways to do it from the web. Take a look at Running Jobs from within a Web Container section of Spring Batch docs.

The idea is simple. You just call jobLauncher.run from within a controller:

@Controller
public class JobLauncherController {

    @Autowired
    JobLauncher jobLauncher;

    @Autowired
    Job job;

    @RequestMapping("/jobLauncher.html")
    public void handle() throws Exception{
        jobLauncher.run(job, new JobParameters());
    }
}

This is Spring MVC (not Struts), but you can see it is very simple, and would work for any controller / action class:

• jobLauncher and job are injected => setJobLauncher(…) / setJob(…)
• jobLauncher runs the job from a jobLauncher.html page (note: the call to run does not block)

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Spring Batch Admin

Another way to launch Spring Batch jobs without worrying about Spring MVC and Struts at all is to use a Spring Batch Admin which is there to solve this exact problem and more (monitoring / stopping / etc..)