java - Servlet web.xml 过滤器——未找到类异常

Question

我在设置过滤器时遇到问题 -我在 web.xml 中定义的过滤器看起来像这样

  <filter>
   <filter-name>Log</filter-name>
   <filter-class>test.log</filter-class> 
 </filter>
 <filter-mapping>
   <filter-name>Log</filter-name>
   <url-pattern>/*</url-pattern>
 </filter-mapping>

但是我收到以下错误 -

SEVERE: Exception starting filter Log
java.lang.ClassNotFoundException: test.log
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1711)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:532)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:514)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:133)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:256)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:382)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:103)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4650)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5306)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

我已经定义了类，但由于某种原因我收到了 Classnotfound 异常。有人可以帮我吗？

编辑 ---

我有一个名为 test 的包和一个名为 log 的类。

             package test;
    import java.io.*;
    import javax.servlet.*;
    import javax.servlet.http.*;
    import java.util.*;

    // Implements Filter class
     public class log implements Filter  {
         public void  init(FilterConfig config) {

          }
         public void  doFilter(ServletRequest request, 
             ServletResponse response,
             FilterChain chain) 
             throws java.io.IOException, ServletException {

  // Get the IP address of client machine.   
  String ipAddress = request.getRemoteAddr();

  // Log the IP address and current timestamp.
  System.out.println("IP "+ ipAddress + ", Time "
                                   + new Date().toString());

  // Pass request back down the filter chain
  chain.doFilter(request,response);
  }
   public void destroy( ){
      /* Called before the Filter instance is removed 
      from service by the web container*/
  }
 }

谢谢，

Answer 1

有趣的是，今天我在昨天工作时也遇到了同样的问题。经过调查显示没有任何问题，我得出结论这是一个 Eclipse 环境问题:

• 停止 tomcat 服务器
• 清理了项目(项目->清理...)
• 刷新整个项目(右键单击项目名称 -> 刷新)
• 重新启动服务器。

问题消失了!