Execution of restartSample through Servlet

[gaurav]

Hello,
I have tried to trigger the execution of the BatchCommandLineLauncher for restartSample through a servlet. For this purpose, I have made following changes in BatchCommandLineLauncher :

• Created Default constructor

/**In BatchCommandLineLauncher code*******/
//appended below lines.

//class level variable or Class Member.
private String beanRefContextPath=null;	
private String parentKey=null;

/**
* When you create the object of BatchCommandLineLauncher,the
* values for beanRefContextPath and parentKey are initialised.
*/
public BatchCommandLineLauncher()
{
beanRefContextPath = System.getProperty(BEAN_REF_CONTEXT_KEY,
				DEFAULT_BEAN_REF_CONTEXT_PATH);
parentKey= System.getProperty(BATCH_EXECUTION_ENVIRONMENT_KEY,
				DEFAULT_PARENT_KEY);
beanFactoryLocator = ContextSingletonBeanFactoryLocator
		.getInstance(beanRefContextPath);
}

• Changed the signature of the start function to :

/**
* No need to provided parentKey parameter as it is * initialised to the required value while creating the * object : command
*/

/**In BatchCommandLineLauncher code*******/
int start(String path, String jobName)




On Client side, I have designed a HTML page with a button. On Click of that button, I have call the servlet. The servlet has following service function :

protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException 
{
	try
	{
	PrintWriter pw=res.getWriter();
	pw.println("Calling BatchCommandLineLauncher default constructor i.e. with " +
				"no parameter");
		/**
		 * When you create the object of BatchCommandLineLauncher, the values for 
		 * beanRefContextPath and parentKey are initialised.
		 */

	BatchCommandLineLauncher command = new BatchCommandLineLauncher();
pw.println("Calling start method of the BatchCommandLineLauncher with parameter :path and jobName");

		/**
		 * No need to provided parentKey parameter as it is initialised to the required
		 * value while creating the object : command 
		 */

int result = command.start("restartSample.xml", "restartSampleJob");		
	pw.println("After start is called.");
		}
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}

But on the click on the button , I encountered an exception on Tomcat console stated :

09:53:09,068 FATAL BatchCommandLineLauncher:276 - org.springframework.beans.fact
ory.BeanCreationException: Error creating bean with name 'restartSampleJob' defi
ned in class path resource [restartSample.xml]: Cannot create inner bean 'step1'
 of type [org.springframework.batch.execution.step.SimpleStepConfiguration] whil
e setting bean property 'steps'; nested exception is org.springframework.beans.f
actory.BeanCreationException: Error creating bean with name 'step1' defined in c
lass path resource [restartSample.xml]: Cannot create inner bean 'ExceptionResta
rtableTasklet#fdb413' of type [ExceptionRestartableTasklet] while setting bean p
roperty 'tasklet'; nested exception is org.springframework.beans.factory.BeanCre
ationException: Error creating bean with name 'ExceptionRestartableTasklet#fdb41
3' defined in class path resource [restartSample.xml]: Cannot create inner bean
'org.springframework.batch.item.provider.ValidatingItemProvider#4b3f8b' of type
[org.springframework.batch.item.provider.ValidatingItemProvider] while setting b
ean property 'itemProvider'; nested exception is org.springframework.beans.facto
ry.BeanCreationException: Error creating bean with name 'org.springframework.bat
ch.item.provider.ValidatingItemProvider#4b3f8b' defined in class path resource [
restartSample.xml]: Cannot resolve reference to bean 'fileInputSource' while set
ting bean property 'inputSource'; nested exception is org.springframework.beans.
factory.BeanCreationException: Error creating bean with name 'fileInputSource':
Initialization of bean failed; nested exception is java.lang.ExceptionInInitiali
zerError

According to my observation, the ConfigurableApplicationContext in start() function is working properly.The exeception is raise at this line :

context = new ClassPathXmlApplicationContext(new String[] {path},parent);

Just for clarification : The values for path and parent which are supplied to above function are proper. I have checked the values by printing method on console.


If someone can help me.
Thanks in advance.

[robert.kasanicky]

The log says there was an error executing a static initializer of the 'fileInputSource' bean - the only static variable I can see in the source code is a logger, so that might be a clue. If logging itself is not the problem try to set log level to debug for the spring framework classes and you should get more information.

[lucasward]

Why are you using the BatchCommandLineLauncher from within a servlet? It's really only intended to allow launching from the command line. Instead, I would use an implementation of the JobLauncher interface, and pass it a JobIdentifier.

[awjohn]

Care to be more specific, w/ sample or document?

[lucasward]

A basic example follows, it assumes that your application contexts have already been loaded at startup:

//assume the context has already been obtained
JobLauncher jobLauncher = (JobLauncher)applicationContext.getBean("jobLauncher");

JobIdentifier myJobId = new Jobidentifier("myJob");

jobLauncher.run(myJobId);

Please excuse any errors, as I just typed it out directly into the post.

This is essentially all the batch command line launcher is doing, except it's doing a lot of work to locate and load application contexts (which isn't necessary in a servlet container) and pull parameters from the command line (also not necessary).

[awjohn]

Thanks!

//assume the context has already been obtained
SimpleJobLauncher jobLauncher = (SimpleJobLauncher)context.getBean( "jobLauncher" );
JobIdentifier myJobId = new SimpleJobIdentifier( "myJob" );
jobLauncher.run( myJobId );

[gaurav]

Lucasward,

Thanks for the suggestion, it worked for me.

[sansun2111]

@ Guarav/All,
Can you be more Specific , even my usecase is some what similar to your code .
I happened to change a little bit of commandline class as per my requirement.
But i want to trigger the batch process with a submit button .

Can you be more specific.

How did you trigger the batch using a screen.

Dumb brain of mine cant understand anything that easily.

Thanks & Regards
Sandeep.S