Java 加载 WebappClassLoader 时出错
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时间：2020-08-12 12:53:27 来源:igfitidea点击:
Error loading WebappClassLoader
提问by user2793926
I am trying a basic servlet application. I created a dynamic web project and add HelloWorld.java to src folder and edit web.xml as below. Then I run the project on server but i get error as follows. I checked for solution online but its not solving my problem..any help?
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 文件夹并编辑 web.xml 如下。然后我在服务器上运行该项目，但出现如下错误。我在网上检查了解决方案，但它没有解决我的问题..有什么帮助吗？
HelloWorld.java
你好世界
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
网页.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>
and the error is,
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)
The classes are not getting generated under WEB-INF I searched alot about this problem but no satisfactory answer to solve my problem. I m trying lot of application using servelets and jsp and html but bcoz of this problem none seems to work..Any help?
这些类没有在 WEB-INF 下生成 我搜索了很多关于这个问题的内容，但没有令人满意的答案来解决我的问题。我正在尝试使用小服务、jsp 和 html 的很多应用程序，但是这个问题的 bcoz 似乎都不起作用..有帮助吗？
采纳答案by Suhas Dalvi
Refresh your project after cleaning it and try to deploy it again..
清理后刷新您的项目并尝试再次部署它..
