先来前jsp页面的代码

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>




     
    
















    

    

        

             餐桌列表
        
    

    






    

        
        
        
    





    

                
                    
                            
                    

        
        

            

                
编号
                
桌名
                
状态
                
预定时间
                
操作
            
        
    
        
        

            

                                
${table.id } 
                                
${table.tableName } 
                                
${table.tableStatus == 1 ? "预定":"空闲" }
                                

                                    
                                
                                

                                    ${table.tableStatus == 1 ? "退订":"预定" }
                                    删除
                                
                            
                        
                
                

                        
没有餐桌信息！请添加后查询。。。。
                    
                
            
        
    
    
   
    

        
添加
    
 

再来后台处理

    public Object updateDinnerTable(HttpServletRequest request, HttpServletResponse response) {
        Object url = null;
        String id = request.getParameter("id");
        String tableStatus = request.getParameter("tableStatus");
        System.out.println(tableStatus);
        //构建对象
        DinnerTable dinnerTable = new DinnerTable();
        dinnerTable.setId(Integer.parseInt(id));
        dinnerTable.setTableStatus(Integer.parseInt(tableStatus));
        Date orderDate = (Integer.parseInt(tableStatus) == 2) ? null:new Date();
        dinnerTable.setOrderDate(orderDate);
        dinnerTableService.update(dinnerTable);
        
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String date = df.format(orderDate);
        try {
            PrintWriter writer = response.getWriter();
            writer.write(date);
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        System.out.println("id:" +id + "; tableStatus:" + tableStatus);
        return url;
    }

来运行结果

然后添加一条数据 再对新添加的数据进行操作就报错了

null
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.uiyllong.servlet.BaseServlet.service(BaseServlet.java:36)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    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:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
    at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2508)
    at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2497)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$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)
Caused by: java.lang.NumberFormatException: null
    at java.lang.Integer.parseInt(Integer.java:542)
    at java.lang.Integer.parseInt(Integer.java:615)
    at com.uiyllong.servlet.DinnerTableServlet.updateDinnerTable(DinnerTableServlet.java:77)
    ... 27 more

请大神看看哪里有问题