一个jsp的问题
我在netbeans中编译项目，数据库用的sqlserver  
 
结果运行时出现了
2007-2-6   10:53:04   org.apache.catalina.core.StandardWrapperValve   invoke

严重:   Servlet.service()   for   servlet   jsp   threw   exception

java.lang.NullPointerException

                at   org.apache.jsp.user.it.index_jsp._jspService(index_jsp.java:71)

                at   org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)

                at   javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

                at   org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)

                at   org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)

                at   org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)

                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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:362)

                at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)

                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)