chengzui 2016-12-10 03:36 采纳率: 13.3%
浏览 2298

java.lang.NumberFormatException: null

at java.lang.Integer.parseInt(Integer.java:542)
at java.lang.Integer.valueOf(Integer.java:766)
at www.pengzheng.web.LoginServlet.service(LoginServlet.java:33)
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:617)
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$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1521)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1478)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

代码:   request.setCharacterEncoding("Utf-8");
    response.setContentType("text/html;charset=utf-8");
    PrintWriter out=response.getWriter();
    Integer empno=Integer.valueOf(request.getParameter("name"));
    out.println(empno);
    EmpDao dao=new EmpDaoImpl();
    Emp emp=dao.queryEmpByNo(empno.intValue());
    if(empno.toString()==""||empno==null){
        out.print("empno为空");
        request.setAttribute("error", "用户编号不存在");
        request.getRequestDispatcher("login.jsp").forward(request, response);
    }
    if(emp!=null){
         request.setAttribute("empno", empno);
         response.sendRedirect("ok.jsp");


            jsp代码:

                 <form method="get" action="login">
   <input  type="text" name="empname" /><span>${error!=null?error:""}</span><br/>
   <input type="submit" value="登录"/>
  </form>
  • 写回答

8条回答

  • baidu_36991216 2016-12-10 03:39
    关注

    Finder的GUI占资源太多

    评论

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