浏览器运行后出现：with root cause java.lang.NullPointerException错误

五月 17, 2015 1:32:45 下午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [jsp] in context with path [/prj_web] threw exception [An exception occurred processing JSP page /registerset.jsp at line 58

55:             try{      //娣诲姞鐢ㄦ埛淇伅 
56:           
57:     String addUser="INSERT INTO user(userid,username,password,name,company,address,sex,interest) VALUES(null,?,?,?,?,?,?,?)";
58:                  pstmt=conn.prepareStatement(addUser);  //棰勫鐞?
59:                        //璁剧疆鍙傛暟
60:                  pstmt.setString(1,reqUsername);
61:                  pstmt.setString(2,reqPassword);


Stacktrace:] with root cause
java.lang.NullPointerException
at org.apache.jsp.registerset_jsp._jspService(registerset_jsp.java:154)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:431)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
不知道哪出问题了，跪求大神指点

4 个解决方案

#1

你的conn

可能是null ，

在查询之前，看看你的conn是否为null值，如果是 则改

#2

已经是null了，但是一运行就指向语句
pstmt=conn.prepareStatement(addUser);
不知道是为何

#3

引用 2 楼 qq_28263531 的回复:

已经是null了，但是一运行就指向语句
pstmt=conn.prepareStatement(addUser);
不知道是为何

都已经是Null了还不改？conn的url  password user  你都配了？

#4

已经解决了，是数据库密码安装时没设，不过还是要谢谢！