加载WebappClassLoader时出错

user2793926 发表于 Dev

用户名

我正在尝试一个基本的servlet应用程序。我创建了一个动态Web项目，并将HelloWorld.java添加到src文件夹，并按如下所示编辑web.xml。然后我在服务器上运行该项目，但出现以下错误。我在线检查了解决方案，但是没有解决我的问题。有什么帮助吗？

HelloWorld.java

    import java.io.*;
    import javax.servlet.*;
    import javax.servlet.http.*;

     public class HelloWorld extends HttpServlet{ 
      public void doGet(HttpServletRequest request, 
      HttpServletResponse response)
      throws ServletException,IOException{
      response.setContentType("text/html");
      PrintWriter pw = response.getWriter();
      pw.println("<html>");
      pw.println("<head><title>Hello World</title></title>");
      pw.println("<body>");
      pw.println("<h1>Hello World</h1>");
      pw.println("</body></html>");
      }
    }

Web.xml

    <?xml version="1.0" encoding="ISO-8859-1"?>
    <!--<!DOCTYPE web-app
     PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
     "http://java.sun.com/dtd/web-app_2_3.dtd"> -->

    <web-app>
     <servlet>
      <servlet-name>Hello</servlet-name>
      <servlet-class>HelloWorld</servlet-class>
     </servlet>
     <servlet-mapping>
     <servlet-name>Hello</servlet-name>
     <url-pattern>/HelloWorld</url-pattern>
     </servlet-mapping>
    </web-app>

错误是

Sep 23, 2013 2:38:37 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:testasu' did not find a matching property.
Sep 23, 2013 2:38:37 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:HelloWorld' did not find a matching property.
Sep 23, 2013 2:38:37 PM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /opt/jdk1.6.0_21/jre/lib/i386/server:/opt/jdk1.6.0_21/jre/lib/i386:/opt/jdk1.6.0_21/jre/../lib/i386:/usr/lib/jvm/java-6-openjdk/jre/lib/i386/client:/usr/lib/jvm/java-6-openjdk/jre/lib/i386:/usr/lib/xulrunner-addons:/usr/lib/xulrunner-addons:/usr/java/packages/lib/i386:/lib:/usr/lib
Sep 23, 2013 2:38:37 PM org.apache.coyote.http11.Http11Protocol init
INFO: Initializing Coyote HTTP/1.1 on http-8080
Sep 23, 2013 2:38:37 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 694 ms
Sep 23, 2013 2:38:38 PM org.apache.catalina.core.StandardService start
INFO: Starting service Catalina
Sep 23, 2013 2:38:38 PM org.apache.catalina.core.StandardEngine start
INFO: Starting Servlet Engine: Apache Tomcat/6.0.18
Sep 23, 2013 2:38:38 PM org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8080
Sep 23, 2013 2:38:38 PM org.apache.jk.common.ChannelSocket init
INFO: JK: ajp13 listening on /0.0.0.0:8009
Sep 23, 2013 2:38:38 PM org.apache.jk.server.JkMain start
INFO: Jk running ID=0 time=0/24  config=null
Sep 23, 2013 2:38:38 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 586 ms
Sep 23, 2013 2:40:01 PM org.apache.catalina.core.ApplicationContext log
INFO: Marking servlet Hello as unavailable
Sep 23, 2013 2:40:01 PM org.apache.catalina.core.ApplicationContext log
SEVERE: Error loading WebappClassLoader
  delegate: false
  repositories:
    /WEB-INF/classes/
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@176c74b
 HelloWorld
java.lang.ClassNotFoundException: HelloWorld
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1094)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:808)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:619)
Sep 23, 2013 2:40:01 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Allocate exception for servlet Hello
java.lang.ClassNotFoundException: HelloWorld
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1094)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:808)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:619)