下面是一个对用户认证的过滤器，在运行的时候就是不对，并且整个项目下的文件访问时都出现相同的错误，不知道哪里错，望哪位帮我改一下。
package com.filter;
import javax.servlet.FilterChain;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import javax.servlet.FilterConfig;
import javax.servlet.http.HttpSession;
public class SignonFilter implements Filter
{
String LOGIN_PAGE="login_signon.jsp";
protected FilterConfig filterConfig;
//过滤处理的方法
public void doFilter(final ServletRequest req,final ServletResponse res,FilterChain chain)throws IOException,ServletException
{
HttpServletRequest hreq = (HttpServletRequest)req;
HttpServletResponse hres = (HttpServletResponse)res;
HttpSession session = hreq.getSession();
String isLogin="";
try
{
isLogin=(String)session.getAttribute("isLogin");
if(isLogin.equals("true"))
{
System.out.println("在SignonFilter中验证通过");
//验证成功，继续处理
chain.doFilter(req,res);
}
else
{
//验证不成功，让用户登录。
hres.sendRedirect(LOGIN_PAGE);
System.out.println("被SignonFilter拦截一个未认证的请求");
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
public void setFilterConfig(final FilterConfig filterConfig)
{
this.filterConfig=filterConfig;
}
//销毁过滤器
public void destroy()
{
this.filterConfig=null;
}
public void init(FilterConfig config) throws ServletException {
this.filterConfig = config;
}
}
web.xml配制如下
<filter-name>auth</filter-name>
<filter-class>com.filter.SignonFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>auth</filter-name>
<url-pattern>/admin/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>com.jspdev.ch8.MyServletContextListener</listener-class>
</listener> //监听器
我用localhost:8080/user/admin/index.jsp访问就出现错误：
java.lang.LinkageError: Class javax/servlet/ServletRequestEvent violates loader constraints
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClass(Unknown Source)
java.security.SecureClassLoader.defineClass(Unknown Source)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1815)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:869)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1322)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1201)
java.lang.ClassLoader.loadClassInternal(Unknown Source)
com.jspdev.ch8.MyRequestListener.requestInitialized(MyRequestListener.java:17)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
java.lang.Thread.run(Unknown Source)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.20 logs.
其它文件也是出现同样的错误，帮帮我吧～～
