SpringMVC REST实现入门级的CRUD

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

首先是web.xml  

<?xml version="1.0" encoding="UTF-8"?>

02	<web-app version="2.5"

03	xmlns="http://java.sun.com/xml/ns/javaee"

04	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

05	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

06	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

07

<servlet>

08	<servlet-name>user</servlet-name>

09	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

10	<load-on-startup>1</load-on-startup>

11	</servlet>

12	<servlet-mapping>

13	<servlet-name>user</servlet-name>

14	<url-pattern>/</url-pattern>

15	</servlet-mapping>

16

17

<filter>

18	<filter-name>SpringCharacterEncodingFilter</filter-name>

19	<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>

20	<init-param>

21	<param-name>encoding</param-name>

22	<param-value>UTF-8</param-value>

23	</init-param>

24

</filter>

25	<filter-mapping>

26	<filter-name>SpringCharacterEncodingFilter</filter-name>

27	<url-pattern>/*</url-pattern>

28	</filter-mapping>

29	</web-app>

然后是SpringMVC的配置文件user-servlet.xml

01	<?xml version="1.0" encoding="UTF-8"?>

02	<beansxmlns="http://www.springframework.org/schema/beans"

03	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

04	xmlns:mvc="http://www.springframework.org/schema/mvc"

05	xmlns:context="http://www.springframework.org/schema/context"

06	xsi:schemaLocation="http://www.springframework.org/schema/beans

07	http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

08	http://www.springframework.org/schema/mvc

09	http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd

10	http://www.springframework.org/schema/context

11	http://www.springframework.org/schema/context/spring-context-3.0.xsd">

12	<context:component-scan base-package="com.jadyer"/>

13

14	<mvc:annotation-driven/>

15

16	<beanclass="org.springframework.web.servlet.view.InternalResourceViewResolver">

17	<property name="prefix" value="/WEB-INF/jsp/"/>

18	<property name="suffix" value=".jsp"/>

19

</bean>

20

</beans>

用来添加用户信息的//WEB-INF//jsp/user/add.jsp

01	<%@ page language="java" pageEncoding="UTF-8"%>

02	<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>

03

04	<%-- 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 --%>

05

06	<form:form method="POST" modelAttribute="user">

07	username: <form:input path="username"/><br/>

08	nickname: <form:input path="nickname"/><br/>

09	password: <form:password path="password"/><br/>

10	yourmail: <form:input path="email"/><br/>

11	<input type="submit" value="添加新用户"/>

12	</form:form>

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

01	<%@ page language="java" pageEncoding="UTF-8"%>

02	<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

03	<c:forEach items="${users}" var="user">

04	${user.value.username}----${user.value.nickname}----${user.value.password}----${user.value.email}

05	<a href="<%=request.getContextPath()%>/user/${user.value.username}">查看</a>

06	<a href="<%=request.getContextPath()%>/user/${user.value.username}/update">编辑</a>

07	<a href="<%=request.getContextPath()%>/user/${user.value.username}/delete">删除</a>

08

<br/>

09	</c:forEach>

10

<br/>

11	<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

1	<%@ page language="java" pageEncoding="UTF-8"%>

2	${user.username}----${user.nickname}----${user.password}----${user.email}

3

<br/>

4

<br/>

5	<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

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

下面是用户的实体类User.java

01 package com.jadyer.model;
02
03 /**
04  * User
05  * @author http://blog.csdn.net/jadyer
06  * @create May 12, 2012 1:24:43 AM
07  */
08 public class User {
09     private String username;
10     private String nickname;
11     private String password;
12     private String email;
13
14     public User() {}
15     public User(String username, String nickname, String password, String email) {
16         this.username = username;
17         this.nickname = nickname;
18         this.password = password;
19         this.email = email;
20     }
21
22     public String getUsername() {
23         return username;
24     }
25     public void setUsername(String username) {
26         this.username = username;
27     }
28     public String getNickname() {
29         return nickname;
30     }
31     public void setNickname(String nickname) {
32         this.nickname = nickname;
33     }
34     public String getPassword() {
35         return password;
36     }
37     public void setPassword(String password) {
38         this.password = password;
39     }
40     public String getEmail() {
41         return email;
42     }
43     public void setEmail(String email) {
44         this.email = email;
45     }
46 }

最后是核心的UserController.java

01 package com.jadyer.controller;
02
03 import java.util.HashMap;
04 import java.util.Map;
05
06 import org.springframework.stereotype.Controller;
07 import org.springframework.ui.Model;
08 importorg.springframework.web.bind.annotation.PathVariable;
09 importorg.springframework.web.bind.annotation.RequestMapping;
10 importorg.springframework.web.bind.annotation.RequestMethod;
11
12 import com.jadyer.model.User;
13
14 /**
15  * UserController
16  * @author http://blog.csdn.net/jadyer
17  * @create May 12, 2012 1:26:21 AM
18  */
19 @Controller
20 @RequestMapping("/user")
21 public class UserController {
22     private final static Map<String,User> users =new HashMap<String,User>();
23
24     //模拟数据源,构造初始数据
25     public UserController(){
26      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]"));
30     }
31
32     /**
33      * 添加新用户
34      * @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
35      */
36     @RequestMapping(value="/add", method=RequestMethod.GET)
37     public String addUser(Model model){
38         //这里要传给前台一个空对象，否则会报告java.lang.IllegalStateException异常
39         //异常信息为Neither BindingResult nor plain target object for bean name 'user' available as request attribute
40         //并且传过去的key值要与前台modelAttribute属性值相同，即model.addAttribute("user", new User());
41         //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
42         model.addAttribute(new User());
43         return "user/add";
44     }
45     @RequestMapping(value="/add", method=RequestMethod.POST)
46     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
47         users.put(user.getUsername(), user);
48         return "redirect:/user/list";
49     }
50
51     /**
52      * 列出所有用户信息
53      */
54     @RequestMapping("/list")
55     public String list(Model model){
56         model.addAttribute("users", users);
57         return "user/list";
58     }
59
60     /**
61      * 查询用户信息
62      * @see 访问该方法的路径就应该是"/user/具体的用户名"
63      * @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
64      * @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
65      */
66     @RequestMapping(value=