在spring mvc中使用hibernate没有将流发送到控制器

Question

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns:p="http://www.springframework.org/schema/p"  
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context="http://www.springframework.org/schema/context"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
        http://www.springframework.org/schema/context  
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">  
   <context:component-scan base-package="com.cgi.controller"/>  
   <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
      <property name="prefix" value="/WEB-INF/JSPS/" />
      <property name="suffix" value=".jsp" />
   </bean>                  
   <bean id="ds" class="org.springframework.jdbc.datasource.DriverManagerDataSource">  
     <property name="driverClassName" value="com.mysql.jdbc.Driver" />  
     <property name="url" value="jdbc:mysql://localhost:3306/tutorial" />  
     <property name="username" value="root" />  
     <property name="password" value="tiger" />  
   </bean>  
   <bean id="mysessionFactory"  class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">  
     <property name="dataSource" ref="ds"></property>  
     <property name="mappingResources">  
       <list><value>Employee.hbm.xml</value></list>  
     </property>  
     <property name="hibernateProperties">  
       <props>  
         <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>  
         <prop key="hibernate.hbm2ddl.auto">update</prop>  
         <prop key="hibernate.show_sql">true</prop>     
       </props>  
     </property>  
    </bean> 
    <bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate"> 
      <property name="sessionFactory" ref="mysessionFactory"/>
    </bean>
    <bean id="LoginDao" class="com.cgi.dao.LoginDaoImpl">  
       <property name="ht" ref="hibernateTemplate"></property>  
    </bean>  
</beans>  

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>Login Example</display-name>
  <welcome-file-list>
    <welcome-file>Login-Form.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>emp</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/Controller-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>emp</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/emp-servlet.xml</param-value>
  </context-param>
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
</web-app>

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.cgi.beans.Employee;
import com.cgi.dao.LoginDaoImpl;

import java.util.*;

@Controller
public class EmployeeController
{
    LoginDaoImpl d;

    @RequestMapping(value="/Check", method=RequestMethod.POST)
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception 
    {
        String name=request.getParameter("username");
        String password=request.getParameter("pass");
        List<Employee> b=(List<Employee>) d.checkuser(name, password);
        System.out.println("Hello");
        Map m=new HashMap();
        m.put("msg", "Hello"+name);

        if(b.size()>0)
        {
            return new ModelAndView("Success",m);
        }
        else
        {
            return new ModelAndView("Fail");
        }
    }

    @RequestMapping(value="/GetAll", method = RequestMethod.POST)
    public ModelAndView getAll(HttpServletRequest request, HttpServletResponse response) throws Exception 
    {
        List<Employee> l=d.getall();

        Map m=new HashMap();
        m.put("msg", l);
        return new ModelAndView("AllUsers",m);
    }

    @RequestMapping("/Register.htm")
    public ModelAndView register(HttpServletRequest req, HttpServletResponse resp) throws Exception
    {
        ApplicationContext ax=new ClassPathXmlApplicationContext("emp-servlet.xml");

        Employee e=(Employee)ax.getBean("d");  
        d.save(e);

        return new ModelAndView("AllUsers");
    }
}

这是jsp文件

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Login Form</title>

</head>
<body>

<form method="post" action="/emp/Check"> 
<center>
<pre>

User-Name: <input id="name" type="text" name="username" required ><br>
Password:  <input id="pswd" type="password" name="pass" required><br>

<input type="submit" value="Submit"><br>

</pre>
</center>
</form> 
</body>
</html>

问题是，虽然在web.xml中有正确的映射方案，但从jsp来看，它不能用于我的控制器。我已经检查了我的网站，但他们都显示相同。如果有人能在他们的系统上运行它并检查它，请…请尽快恢复。

错误报告。

在路径为[/employee_management_tool]的上下文中，servlet[emp]的servlet.service（）引发异常[请求处理失败；嵌套异常是java.lang.NullPointerException]，根原因是java.lang.NullPointerException位于com.cgi.controller.employeeController.handlerequest（EmployeeController.java:28)位于sun.reflect.nativeMethodAccessorImpl.Invoke0（本机方法）位于d.annotation.support.handlerMethodInvoker.doinvokeMethod（handlerMethodInvoker.java:710)在org.springframework.web.bind.annotation.support.handlerMethodInvoker.invoke.invokeMethod(handlerMethodInvoker.java:167)在org.springframework.web.servlet.mvc.annotation.annotation.annotation.annotationMethod(annotlerMethodInvoker.java:167)在tationMethodHandlerAdapter.handle（AnnotationMethodHandlerAdapter.java:402)在org.springframework.web.servlet.dispatcherServlet.doDispatch（DispatcherServlet.java:771)在org.springframework.web.servlet.dispatcherServlet.doService（DispatcherServlet.java:716)在org.springframework.web.servlet.frameworkServlet.processRequest（服务(httpservlet.java:729)，org.apache.catalina.core.applicationFilterChain.InternaldoFilter(applicationFilterChain.java:291)，org.apache.catalina.core.applicationFilterChain.doFilter(applicationFilterChain.java:206)，org.apache.catalina.core.wsfilter.doFilter(applicationFilterChain.java:206)，org.apache.tomcat.websocket.wsfilter.doFiltercationFilterChain.java:206)在org.apache.catalina.core.standardWrapperValve.invoke(StandardWrapperValve.java:212)在org.apache.catalina.core.standardContextValve.invoke(StandardContextValve.invoke(StandardContextValve.java:106)在valves.abstractAccessLogValve.invoke(abstractAccessLogValve.java:616)在org.apache.catalina.core.standardEnginEvalve.invoke(StandardEnginEvalve.java:88)在org.apache.catalina.connector.coyoteAdapter.Service(coyoteAdapter.java:521)在org.apache.coyote.http11.abstractThttp11Processor.Process(abstractThttp11Processore.java:1096)在nioEndpoint.java:1500)在org.apache.tomcat.util.net.nioEndpoint$socketprocessor.run（nioEndpoint.java:1456)在java.util.concurrent.threadpoolexecutor.runworker（未知源）在java.util.concurrent.threadpoolexecutor$worker.run（未知源）在org.apache.tomcat.util.threads.taskthread$wrappingrunnable.run（taskthread.java.lang.thread.run（未知源）

Answer 1

>

检查您的jsp文件是否在'/WEB-INF/jsps/'文件夹中。

检查web.xml，“context configlocation”被提到了两次。见下文

<servlet>
<servlet-name>emp</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>/WEB-INF/Controller-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>

再用另一个值

  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/emp-servlet.xml</param-value>
  </context-param>

我认为您应该删除第二个，并用值'/WEB-INF/emp-servlet.xml'更正第一个。