如何解决Servelts中的非法状态异常

异常跟踪：

""java.lang.IllegalStateException: 在 org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:328) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java)提交响应后无法转发:318) 在 com.zoho.campaign.client.filters.CampaignDomainFilter.doFilter(CampaignDomainFilter.java:140) 在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) 在 org.apache.catalina。 core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at com.zoho.campaign.client.filters.CampaignDefaultFilter.doFilter(CampaignDefaultFilter.java:165) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java: 240) 在 org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 在 com.adventnet.iam.security.SecurityFilter.doFilter(SecurityFilter.java:217) 在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) 在 org.apache.catalina.core.ApplicationFilterChain .doFilter(ApplicationFilterChain.java:207) at com.adventnet.zoho.crmplus.agent.filter.CRMPlusFilter.doFilter(CRMPlusFilter.java:55) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) ) 在 org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) 在 com.zoho.logs.logclient.filter.AccessLogFilter.doFilter(AccessLogFilter.java:61) 在 org.apache.catalina.core。 ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at com.zoho。instrument.InstrumentFilter.doFilter(InstrumentFilter.java:37) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)在 org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) 在 org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) 在 org.apache.catalina.authenticatorBase.inventicator.invent (AuthenticatorBase.java:502) at org.apache.catalina.valves.rewrite.RewriteValve.invoke(RewriteValve.java:480) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) at org. apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.authenticator.SingleSignOn.invoke(SingleSignOn.java:240) at org.apache。catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java) 1099) 在 org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 在 org.apache.tomcat .util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476) 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java) :617) 在 org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 在 java.lang.Thread.run(Thread.java:745)invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099) at org.apache .coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 在 org.apache.tomcat.util.net.NioEndpoint $SocketProcessor.run(NioEndpoint.java:1476) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org. apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 在 java.lang.Thread.run(Thread.java:745)invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099) at org.apache .coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 在 org.apache.tomcat.util.net.NioEndpoint $SocketProcessor.run(NioEndpoint.java:1476) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org. apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 在 java.lang.Thread.run(Thread.java:745)java:528) 在 org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099) 在 org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) 在 org.apache.tomcat.util .net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476) 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor) .java:1142) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 在 org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 在 java。 lang.Thread.run(Thread.java:745)java:528) 在 org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099) 在 org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672) 在 org.apache.tomcat.util .net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476) 在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor) .java:1142) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 在 org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) 在 java。 lang.Thread.run(Thread.java:745)java:672) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 在 org.apache.tomcat.util.threads.TaskThread$WrappingRunnable .run(TaskThread.java:61) 在 java.lang.Thread.run(Thread.java:745)java:672) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) 在 org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)在 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 在 org.apache.tomcat.util.threads.TaskThread$WrappingRunnable .run(TaskThread.java:61) 在 java.lang.Thread.run(Thread.java:745)TaskThread$WrappingRunnable.run(TaskThread.java:61) 在 java.lang.Thread.run(Thread.java:745)TaskThread$WrappingRunnable.run(TaskThread.java:61) 在 java.lang.Thread.run(Thread.java:745)

当尝试转发 RequestDispatcher 我得到这个异常

出现此问题的原因是什么？

代码：

public void doFilter(ServletRequest req,ServleResponse res,FilterChain filterchain)thorws IOException,Exception
{
String downloaurl="expired";
boolean is_allow_download=false;
HttpServletRequest request=(HttpServletRequest)req;
HttpServletResponse response=(HttpServletResponse)res;
RequestDispatcher rd=null;
if(downloadurl.equals("expired"))
    {
    request.setAttribute("isexpire", "expire");
  }
  else if(downloadurl.equals("no_data"))
     {
       request.setAttribute("isdataAval", false);
  }
     if(url1.contains("export.do") && !downloadurl.equals("no_data") && is_allow_download )
       {
         rdc = request.getRequestDispatcher("users/export.do");
         rdc.forward(request, response);
       }
      rdc = request.getRequestDispatcher("users/closed.do"); 
        rdc.forward(request, response);

}