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

01package com.jadyer.model; 

02   

03/**

04 * User

05 * @author http://blog.csdn.net/jadyer

06 * @create May 12, 2012 1:24:43 AM

07 */ 

08public 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

01package com.jadyer.controller; 

02   

03import java.util.HashMap; 

04import java.util.Map; 

05   

06import org.springframework.stereotype.Controller; 

07import org.springframework.ui.Model; 

08importorg.springframework.web.bind.annotation.PathVariable; 

09importorg.springframework.web.bind.annotation.RequestMapping; 

10importorg.springframework.web.bind.annotation.RequestMethod; 

11   

12import 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") 

21public 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", "[e-mail]"));

      users.put("李寻欢", new User("李寻欢", "李探花", "08866659", "[e-mail]"));

      users.put("拓拔野", new User("拓拔野", "搜神记", "05577759", "[e-mail]"));

      users.put("孙悟空", new User("孙悟空", "美猴王", "03311159", "[e-mail]"));

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="/{myname}", method=RequestMethod.GET) 

67    public String show(@PathVariable String myname, Model model){ 

68        model.addAttribute(users.get(myname)); 

69        return "user/show"; 

70    } 

71       

72    /**

73     * 编辑用户信息

74     * @see 访问该方法的路径就应该是"/user/具体的用户名/update"

75     */ 

76    @RequestMapping(value="/{myname}/update", method=RequestMethod.GET) 

77    public String update(@PathVariable String myname, Model model){ 

78        model.addAttribute(users.get(myname)); 

79        return "user/update"; 

80    } 

81    @RequestMapping(value="/{myname}/update", method=RequestMethod.POST) 

82    public String update(User user){ 

83        users.put(user.getUsername(), user); 

84        return "redirect:/user/list"; //也可以retun "forward:/user/list",此时浏览器地址栏会有不同 

85    } 

86       

87    /**

88     * 删除用户信息

89     */ 

90    @RequestMapping(value="/{myname}/delete", method=RequestMethod.GET) 

91    public String delete(@PathVariable String myname){ 

92        users.remove(myname); 

93        return "redirect:/user/list"; //删除完成后显示当前存在的所有用户信息 

94    } 

95}