求解答

Question

严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.chat_jsp._jspService(chat_jsp.java:87)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:384)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:445)
at java.lang.Thread.run(Unknown Source)这个错位在我要怎么找啊？？？

Answer 1

at org.apache.jsp.chat_jsp._jspService(chat_jsp.java:87)你把代码使用 <% %> 写在 JSP 中，只有你自己慢慢去找吧，如果看得懂 Tomcat 把 JSP 翻译成 Java 后的代码，你也可以往那儿去找。

Answer 2

那Tomcat把jsp翻译成java的代码在哪里呢？

Answer 3

（tomcat安装路径）\work\Catalina\localhost\你的项目名\org\apache\jsp或者你的项目配置的work目录下

Answer 4

chat_jsp.java:87  直接打断点 debug jsp

Answer 5

java.lang.NullPointerException 空指针异常 
没有判断 object !=null

Answer 6

chat_jsp.java:87 这个jsp 看看差不多87行的左右有错.

Answer 7

同意楼上的。你怎么也不贴代码，自己慢慢去那个jsp找吧