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

严重: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
at org.apache.jsp.login_002dcheck_jsp._jspService(login_002dcheck_jsp.java:113)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
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:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)

获取值失败出现空指针一场或者配置文件不正确

要么是你后台的方法是对的 但是接收不到页面的值，要么你方法写错了

是不是没输入用户名就提交啊???

没找到user类下的getuser_id()这个方法，有可能是你的jsp页面中没有引入这个类

没获取到值，查看下你的login_002dcheck_jsp页面或者看下你程序里面的SQL语句，最好测试下那个方法~~~

你的jsp页面中的java代码有空指针异常 java.lang.NullPointerException at org.apache.jsp.login_002dcheck_jsp._jspService(login_002dcheck_jsp.java:113)