Hey!
I see that no one replied to you basic-Java question, so I will
give you a clue.
Study some more on packages in your Java book, and understand
why you got the class loader error message. It is saying it can
not find one of the classes that it needs.
There are several ways for organizing you application, too
many to give you a concrete answer. I believe
you will find your own solution with a little basic-Java studying.
If you still have problems, E-mail me privately for your
question.
Sasn adieu,
Danny Rubis
Ying Su wrote:
> Dear all,
> After corrected the typo pointed out by Geeta, My Handler servlet can work now. But
>I have new prolems now: I made a myTest.jar file which included the "Test.class" and
>put it in the same path as Handler.class. Then I configured the JBuilder's "required
>libaries" and added the myTest.jar.
>
> Now My Handler.java is:
>
> import java.io.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
> import javax.xml.bind.*;
> import com.gxmlhub.msgsvc.server.*;
>
> public class Handler extends Test {
>
> public void service(HttpServletRequest request, HttpServletResponse response)
>throws IOException,ServletException
> {
> super.service(request,response);
> }
> public void onMessage(HttpServletRequest request, HttpServletResponse response)
>throws IOException,ServletException
> {
> response.setContentType("text/html");
>
> PrintWriter out = response.getWriter();
>
> out.println("<h1>onMessage by Handler!!!!</h1>");
>
> }
> }
>
> My Test.java is(Please note that I added the "package"sentence in it):
>
> package com.gxmlhub.msgsvc.server;
> import java.io.*;
> import java.net.*;
> import java.text.*;
> import java.util.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> public class Test extends HttpServlet {
>
> public void service(HttpServletRequest request, HttpServletResponse response)
> throws IOException,ServletException
> {
> response.setContentType("text/html");
> PrintWriter out = response.getWriter();
> out.println("<html>");
> out.println("<body>");
> out.println("<head>");
> out.println("<title>Hello World!</title>");
> out.println("</head>");
> out.println("<body>");
> out.println("<h1>Hello World!</h1>");
>
> onMessage(request,response);
> out.println("</body>");
> out.println("</html>");
> }
> public void onMessage(HttpServletRequest request, HttpServletResponse response)
> throws IOException,ServletException
> {
> PrintWriter out = response.getWriter();
> out.println("<h1>onMessage by Test</h1>");
> }
> }
>
> When I want to run the Handler servlet, JBUilder gives me the following errors:
> Error: 500 Location: /servlet/Handler
> Internal Servlet Error:java.lang.NullPointerException
> at java.lang.ClassLoader.resolveClass0(Native Method)
> at java.lang.ClassLoader.resolveClass(ClassLoader.java:588)
> at
>org.apache.tomcat.loader.AdaptiveClassLoader.loadClass(AdaptiveClassLoader.java:430)
> at
>org.apache.tomcat.loader.AdaptiveServletLoader.loadClass(AdaptiveServletLoader.java:174)
> at org.apache.tomcat.core.ServletWrapper.loadServlet(ServletWrapper.java:265)
> at org.apache.tomcat.core.ServletWrapper.init(ServletWrapper.java:289)
> at org.apache.tomcat.core.Handler.service(Handler.java:254)
> at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
> at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812)
> at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
> at
>org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
> at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
> at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
> at java.lang.Thread.run(Thread.java:484)
>
> Can anyone tell me how to deal with it? Thanks!
>
> Ying
>
> ----- Original Message -----
> From: Ying Su
> To: [EMAIL PROTECTED]
> Sent: Thursday, March 14, 2002 10:46 AM
> Subject: Can a servlet extends another servlet?
>
> Dear all,
> I wrote a servlet "Test.java" which contains a service(request,response) method, and
>it works properly. Then I want to write another servlet "Handler.java" which extends
>the "Test" class, and in Handler.java, I overrides the service(request,response)
>method. It was compiled succesfully,but can not run. I use JBuilder to run my
>servlets, and it gives the following error:
>
> Error: 500 Location: /servlet/Handler
> Internal Servlet Error:java.lang.NullPointerException
> at java.lang.ClassLoader.resolveClass0(Native Method)
> at java.lang.ClassLoader.resolveClass(ClassLoader.java:588)
> at
>org.apache.tomcat.loader.AdaptiveClassLoader.loadClass(AdaptiveClassLoader.java:430)
> at
>org.apache.tomcat.loader.AdaptiveServletLoader.loadClass(AdaptiveServletLoader.java:174)
> at org.apache.tomcat.core.ServletWrapper.loadServlet(ServletWrapper.java:265)
> at org.apache.tomcat.core.ServletWrapper.init(ServletWrapper.java:289)
> at org.apache.tomcat.core.Handler.service(Handler.java:254)
> at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
> at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812)
> at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
> at
>org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
> at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
> at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
> at java.lang.Thread.run(Thread.java:484)
>
> Can anyone answer my question? Thanks a lot!
>
> My Test.java:
>
> import java.io.*;
> import java.net.*;
> import java.text.*;
> import java.util.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> public class Test extends HttpServlet {
>
> public void service(HttpServletRequest request, HttpServletResponse response)
> throws IOException,ServletException
> {
> response.setContentType("text/html");
> PrintWriter out = response.getWriter();
> out.println("<html>");
> out.println("<body>");
> out.println("<head>");
> out.println("<title>Hello World!</title>");
> out.println("</head>");
> out.println("<body>");
> out.println("<h1>Hello World!</h1>");
>
> onMessage(request,response);
> out.println("</body>");
> out.println("</html>");
> }
> public void onMessage(HttpServletRequest request, HttpServletResponse response)
> throws IOException,ServletException
> {
> PrintWriter out = response.getWriter();
> out.println("<h1>onMessage?</h1>");
> }
> }
>
> My Handler.java
>
> import java.io.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> public class Handler extends Test {
>
> public void service(HttpServletRequest request, HttpServletResponse
>response)throws IOException,ServletException
> {
> super.service(request,response);
> }
>
> public void onMessage(HttpServletRequest request, HttpServletResponse
>response)throws IOException,ServletException
> {
> response.setContentType("text/html");
>
> PrintWriter out = null;
>
> out = response.getWriter();
>
> out.println("<h1>EbXMLHandler!!!!</h1>");
>
> }
> }
>
> best regards!
> Sincerely
> Ying
> Nrzǧu [h+-ڲܢfv)ܖ^ {ay ʇ鞲 z HDU,D51 $b!
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>mjw(kۜzzkz.Ǭ٥,HDU ii0[(~(楳ztml=
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