Calling Spring Batch from java code

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 (eg 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..)

Answer 2

Struts action classes are normal classes and you can write any code which you want to write inside this. S2 will by dafault call the execute method insdie your action class untill you have specified any other method name in your configuration file. all you need to do the following steps

1. Create an action class with execute method.
2. Create a service class with a method which have your batch processing logic.
3. Call the service class from your action class

For sending the value of file name from your jsp all you need to create an input field like

<s:textfield name="fileName" id="fileName"/>

create a property in your action class with name fileName and its getter and setter.All you need to pass the file name to your batch processing service class method.In short you should have a flow similar to this

public class BatchProcessingAction extends ActionSupport{

    private string fileName;
    private ServiceClass serviceClass;

    getter ans setter for above defined properties

    public string execute() throw Exeption{
            serviceclass=new ServiceClass();  // can use Di or factory for this
            serviceClass.executeBatchProcessing(fileName);
            return SUCCESS;
    }

}