How to load a java class when application is at first time browsed.

Question

Hi
How can i load a simple java class on application startup.
For servlet it could be done using "load on startup" tag in web.xml
but how could the same be achieved for a simple java class.
Thanks

Answer 1

Hi
Code is given below....
package com;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test {
Test()
     HttpServletRequest request=null;
     HttpServletResponse response=null;
     RequestDispatcher requestDispatcher = request.getRequestDispatcher("a.jsp");
     try {
          requestDispatcher.forward(request,response);
     } catch (ServletException e) {
          System.out.println("success");
          e.printStackTrace();
     } catch (IOException e) {
          System.out.println("success 1");
          e.printStackTrace();
     finally
          System.out.println("success 2");
     System.out.println("success 3");
}Web.xml :
<servlet>
        <servlet-name>simple</servlet-name>
        <servlet-class>com.Test</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
  <servlet-mapping>
      <servlet-name>simple</servlet-name>
      <url-pattern>/init.do</url-pattern>
    </servlet-mapping>Error Trace :
org.apache.catalina.core.StandardContext loadOnStartup
SEVERE: Servlet /DispatcherTest threw load() exception
java.lang.IllegalAccessException: Class org.apache.catalina.core.StandardWrapper can not access a member of class com.Test with modifiers ""
     at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:65)
     at java.lang.Class.newInstance0(Class.java:344)
     at java.lang.Class.newInstance(Class.java:303)
     at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1048)
     at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:925)
     at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:3857)
     at org.apache.catalina.core.StandardContext.start(StandardContext.java:4118)
     at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1069)
     at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1162)
     at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:293)
     at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
     at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1304)
     at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1568)
     at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1577)
     at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1557)
     at java.lang.Thread.run(Thread.java:595)