jsp 页面会出新这种异常，请朋友们帮忙看一下，谢谢！

Question

[2011-01-01 17:47:21] Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp._3g.index_jsp._jspService(index_jsp.java:77)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:416)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:200)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:775)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:704)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:897)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:619)
[2011-01-01 17:48:36] Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp._3g.index_jsp._jspService(index_jsp.java:77)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:331)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:416)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:200)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:775)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:704)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:897)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:619)
[2011-01-01 17:48:44] Servlet.service() for servlet jsp threw exception

Answer 1

空指针，你看看jsp是不是某个地方的变量为空了

Answer 2

NullPointerException应该是最好解决的了，就是有东西没初始化呗

Answer 3

index_jsp.java:77
这个页面的77行报空指针

Answer 4

有一个对象拿到的值是Null 或者没有初始化就用了可能你刷新的时候会把某个变量的值编程null所以就出现这个问题了

Answer 5

努力,有一个对象拿到的值是Null 吧?

Answer 6

找你tomcat work路径下生成的那个jsp然后在对照报错自己找找