calling destroy() from init()

[Lalit Bansal]

I've made a servlet extending GenericServlet. My servlet contains init(), service() and destroy() methods.
From the init() method I make a call to destroy() method.

However on executing my servlet, the control still goes to service() method.

Pls clarify.

Pls see below my servlet class.

***************************************************************************

 
package com.myCompany.controller;
 
import java.io.IOException;
import javax.servlet.GenericServlet;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
 
/**
 * @version 1.0
 * @author
 */
public class MyServlet extends GenericServlet {
 
/**
* @see javax.servlet.GenericServlet#void ()
*/
public void init() throws ServletException {
 
System.out.println("In it");
destroy();

 
}
 
/**
* @see javax.servlet.GenericServlet#void (javax.servlet.ServletRequest, javax.servlet.ServletResponse)
*/
public void service(ServletRequest arg0, ServletResponse arg1)
throws ServletException, IOException {
System.out.println("Hello World");
 
}
 
/**
* @see javax.servlet.GenericServlet#void ()
*/
public void destroy() {
 
super.destroy();
 
}
 
}

***************************************************************************



[BPSouther: Added code tags]
[ August 07, 2007: Message edited by: Ben Souther ]

[Mani Ram]

Note that a call to destroy() method will not destroy a servlet. If you are calling the destroy() method from init (or any other place for that matter), the destroy() method will execute like any other method and the control will return to the calling method once the destroy method is done with it's execution.
In other words, there is nothing special with the destroy method, apart from the fact that it will be called by the container automatically, when it is required.

[Amol Nayak]

See, the destroy is called when the container wishes to take the servlet out of service.

but the converse is not true, that is if destroy is called by us the servlet is not taken out of service.

Is just a callback method that is called by the container to give us the last chance of cleaning up something before the servlet is taken out and garbage collected.

Hopes that answers your question.

[Lalit Bansal]

Thanks Mani & Amol.

I've got the concept.

[Lalit Bansal]

Just for my knowledge, can you clarify which method actually takes the servlet out of memory. In other words where is the actual implementation of removing servlet from memory.
If it is in container, then will it be vendor specific? Can we customize it?
Also on what basis will the container decide to remove the servlet.

[Amol Nayak]

As a servlet developer you have no control over this.

It is decided by the container when to remove the servlet instance from memory.

[Ben Souther]

Originally posted by Lalit Bansal:
Just for my knowledge, can you clarify which method actually takes the servlet out of memory. In other words where is the actual implementation of removing servlet from memory.
If it is in container, then will it be vendor specific? Can we customize it?
Also on what basis will the container decide to remove the servlet.

These things are left to the container developers.
We (application developers) shouldn't concern ourselves the the lower level inner workings of the container.

[Lalit Bansal]

Thanks to all of you for the clarification.

Request to moderator to please close the topic thread.

[Ben Souther]

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