SpringMVC结合REST实现入门级的CRUD

 转自：http://www.open-open.com/lib/view/open1379302151537.html

 

这是一个WebProject，用到的是spring-framework-3.1.1.RELEASE

 

 

首先是web.xml（最终应用访问地址为http://IP:port/contextPath/user/add）

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <servlet>
        <servlet-name>user</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>user</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
 
    <filter>
        <filter-name>SpringCharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>SpringCharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

 然后是SpringMVC的配置文件user-servlet.xml

 

<?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: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/mvc
                        http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
                        http://www.springframework.org/schema/context
                        http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    <context:component-scan base-package="com.jadyer"/>
     
    <mvc:annotation-driven/>
     
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

 用来添加用户信息的//WEB-INF//jsp/user/add.jsp

 

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
 
<%-- 这里并没有指定action=""，说明表单是提交给自己的，说白了就是"哪来的回哪儿去 --%>
 
<form:form method="POST" modelAttribute="user">
    username: <form:input path="username"/><br/>
    nickname: <form:input path="nickname"/><br/>
    password: <form:password path="password"/><br/>
    yourmail: <form:input path="email"/><br/>
    <input type="submit" value="添加新用户"/>
</form:form>

 用来列出所有用户信息的//WEB-INF//jsp/user/list.jsp

 

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<c:forEach items="${users}" var="user">
    ${user.value.username}----${user.value.nickname}----${user.value.password}----${user.value.email}
        <a href="<%=request.getContextPath()%>/user/${user.value.username}">查看</a>
        <a href="<%=request.getContextPath()%>/user/${user.value.username}/update">编辑</a>
        <a href="<%=request.getContextPath()%>/user/${user.value.username}/delete">删除</a>
    <br/>
</c:forEach>
<br/>
<a href="<%=request.getContextPath()%>/user/add">继续添加用户</a>

 用来显示单个用户信息的//WEB-INF//jsp/user/show.jsp

 

<%@ page language="java" pageEncoding="UTF-8"%>
${user.username}----${user.nickname}----${user.password}----${user.email}
<br/>
<br/>
<a href="<%=request.getContextPath()%>/user/add">继续添加用户</a>

 用来更新单个用户信息的//WEB-INF//jsp/user/update.jsp

 

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<form:form method="POST" modelAttribute="user">
    username: <form:input path="username"/><br/>
    nickname: <form:input path="nickname"/><br/>
    password: <form:password path="password"/><br/>
    yourmail: <form:input path="email"/><br/>
    <input type="submit" value="更新用户信息"/>
</form:form>

 下面是用户的实体类User.java

 

package com.jadyer.model;
 
/**
 * User
 * @author http://blog.csdn.net/jadyer
 * @create May 12, 2012 1:24:43 AM
 */
public class User {
    private String username;
    private String nickname;
    private String password;
    private String email;
     
    public User() {}
    public User(String username, String nickname, String password, String email) {
        this.username = username;
        this.nickname = nickname;
        this.password = password;
        this.email = email;
    }
     
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getNickname() {
        return nickname;
    }
    public void setNickname(String nickname) {
        this.nickname = nickname;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
}

 最后是核心的UserController.java

 

package com.jadyer.controller;
 
import java.util.HashMap;
import java.util.Map;
 
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
 
import com.jadyer.model.User;
 
/**
 * UserController
 * @author http://blog.csdn.net/jadyer
 * @create May 12, 2012 1:26:21 AM
 */
@Controller
@RequestMapping("/user")
public class UserController {
    private final static Map<String,User> users = new HashMap<String,User>();
     
    //模拟数据源,构造初始数据
    public UserController(){
        users.put("张起灵", new User("张起灵", "闷油瓶", "02200059", "[email protected]"));
        users.put("李寻欢", new User("李寻欢", "李探花", "08866659", "[email protected]"));
        users.put("拓拔野", new User("拓拔野", "搜神记", "05577759", "[email protected]"));
        users.put("孙悟空", new User("孙悟空", "美猴王", "03311159", "[email protected]"));
    }
     
    /**
     * 添加新用户
     * @see 访问/user/add时，GET请求就执行addUser(Model model)方法，POST请求就执行addUser(User user)方法
     */
    @RequestMapping(value="/add", method=RequestMethod.GET)
    public String addUser(Model model){
        //这里要传给前台一个空对象，否则会报告java.lang.IllegalStateException异常
        //异常信息为Neither BindingResult nor plain target object for bean name 'user' available as request attribute
        //并且传过去的key值要与前台modelAttribute属性值相同，即model.addAttribute("user", new User());
        //我们也可以写成下面这种方式，此时SpringMVC会自动把对象名转换为小写值作为key，即User-->user
        model.addAttribute(new User());
        return "user/add";
    }
    @RequestMapping(value="/add", method=RequestMethod.POST)
    public String addUser(User user){ //这里参数中的user就应该与add.jsp中的modelAttribute="user"一致了
        users.put(user.getUsername(), user);
        return "redirect:/user/list";
    }
     
    /**
     * 列出所有用户信息
     */
    @RequestMapping("/list")
    public String list(Model model){
        model.addAttribute("users", users);
        return "user/list";
    }
     
    /**
     * 查询用户信息
     * @see 访问该方法的路径就应该是"/user/具体的用户名"
     * @see 这里value="/{username}"的写法，需要格外注意一下，它是一个路径变量，此时用来接收前台的一个资源
     * @see 这时value="/{username}"就会到方法参数中找@PathVariable String username，并将路径变量值传给username参数
     */
    @RequestMapping(value="/{myname}", method=RequestMethod.GET)
    public String show(@PathVariable String myname, Model model){
        model.addAttribute(users.get(myname));
        return "user/show";
    }
     
    /**
     * 编辑用户信息
     * @see 访问该方法的路径就应该是"/user/具体的用户名/update"
     */
    @RequestMapping(value="/{myname}/update", method=RequestMethod.GET)
    public String update(@PathVariable String myname, Model model){
        model.addAttribute(users.get(myname));
        return "user/update";
    }
    @RequestMapping(value="/{myname}/update", method=RequestMethod.POST)
    public String update(User user){
        users.put(user.getUsername(), user);
        return "redirect:/user/list"; //也可以retun "forward:/user/list",此时浏览器地址栏会有不同
    }
     
    /**
     * 删除用户信息
     */
    @RequestMapping(value="/{myname}/delete", method=RequestMethod.GET)
    public String delete(@PathVariable String myname){
        users.remove(myname);
        return "redirect:/user/list"; //删除完成后显示当前存在的所有用户信息
    }
}