Error 500 -- Internal Server Error

java.lang.NoClassDefFoundError: java/lang/StringBuilder
    at vijay.servlets.Login.doGet(Login.java:35)
    at javax.servlet.http.HttpServlet.service(HttpServlet .java:740)
    at javax.servlet.http.HttpServlet.service(HttpServlet .java:853)
    at weblogic.servlet.internal.ServletStubImpl$ServletI nvocationAction.run(ServletStubImpl.java:1006)
    at weblogic.servlet.internal.ServletStubImpl.invokeSe rvlet(ServletStubImpl.java:419)
    at weblogic.servlet.internal.ServletStubImpl.invokeSe rvlet(ServletStubImpl.java:315)
    at weblogic.servlet.internal.WebAppServletContext$Ser vletInvocationAction.run(WebAppServletContext.java :6718)
    at weblogic.security.acl.internal.AuthenticatedSubjec t.doAs(AuthenticatedSubject.java:321)
    at weblogic.security.service.SecurityManager.runAs(Se curityManager.java:121)
    at weblogic.servlet.internal.WebAppServletContext.inv okeServlet(WebAppServletContext.java:3764)
    at weblogic.servlet.internal.ServletRequestImpl.execu te(ServletRequestImpl.java:2644)
    at weblogic.kernel.ExecuteThread.execute(ExecuteThrea d.java:219)
    at weblogic.kernel.ExecuteThread.run(ExecuteThread.ja va:178)

This is the error which I got while working with servlets. I am getting the above error when I submit the page. I am using weblogic as the application server. Help me out in finding the error.

Vijay

Can u post a part of ur java code. did u place ur .class file inside web-inf/classes directory with fully qualified class name...

Hi,
you are trying to use StringBuilder class in your servlet, and you've mentioned that you're using Weblogic as your server, weblogic comes with its own JDK check the version of the jdk used by weblogic as StringBuilder is part of JDK 1.5 not part of JDK 1.4, I think your weblogic is using JDK1.4 thats why you are getting the NoClassDefFoundError for StringBuilder class

You can check the API doc for StringBuilder its in java.lang package

Regards,
Rakesh