> 下载了文件
> 安装了程序
> 可是还出错
> 
> 例如 主页上有
> Exception Occurred
> 
>   
> Exception stack 
> java.lang.NullPointerException
> 	at com.pku.judgeonline.common.FormattedOut.printHead(Unknown Source)
> 	at com.pku.judgeonline.servlet.Index.doGet(Unknown Source)
> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
> 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
> 	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
> 	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
> 	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
> 	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
> 	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
> 	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
> 	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
> 	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
> 	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856)
> 	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744)
> 	at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
> 	at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
> 	at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
> 	at java.lang.Thread.run(Unknown Source
> 怎么办啊？
> 论坛回复可能看不到
> QQ:378468086联系我 谢谢