SpringMVC4.0实现rest风格接口，json格式请求和返回

1.项目结构和引入的包：

2.web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>springmvc</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

3.springmvc-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:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">                    

    <!-- scan the package and the sub package -->
    <context:component-scan base-package="test"/>

    <!-- don't handle the static resource -->
    <mvc:default-servlet-handler />

    <!-- if you use annotation you must configure following setting -->
    <mvc:annotation-driven />

    <!-- configure the InternalResourceViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" 
            id="internalResourceViewResolver">
        <!-- 前缀 -->
        <property name="prefix" value="/WEB-INF/jsp/" />
        <!-- 后缀 -->
        <property name="suffix" value=".jsp" />
    </bean>
    <!-- json return -->
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
       <property name="messageConverters">  
           <list>  
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"></bean>      
           </list>  
       </property>  
   </bean>  
</beans>

4.实体类Student.java:

package test;

public class Student {

    private int id;
    private String name;
    private int age;
    private String sex;
    private String major;


    public Student() {

    }

    //此方法会将默认的无参构造方法给覆盖掉，必须加上上面的无参构造方法
    public Student(int id, String name, int age, String sex, String major) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
        this.sex = sex;
        this.major = major;
    }

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String getMajor() {
        return major;
    }
    public void setMajor(String major) {
        this.major = major;
    }

}

5.RestController.java:

package test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;

import javax.servlet.http.HttpSession;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@RequestMapping("/rest")
public class RestController {

    //存储学生信息
    private List<Student> sList = new ArrayList<Student>();

    //初始化
    public RestController(){
        Student s1 = new Student(2017001, "张三", 23, "男", "计算机");
        Student s2 = new Student(2017002, "李四", 23, "男", "计算机");
        Student s3 = new Student(2017003, "王五", 23, "男", "计算机");
        sList.add(s1);
        sList.add(s2);
        sList.add(s3);
    }

    //查询所有
    @ResponseBody
    @RequestMapping(value="/student",method=RequestMethod.GET)
    public Object getAll(){
        System.out.println("GET:ALL"); 
        return sList;
    }

    //查询单个
    @ResponseBody
    @RequestMapping(value="/student/{id}",method=RequestMethod.GET)
    public Object getOne(@PathVariable("id") Integer id){
        System.out.println("GET:"+id);
        List<Student> selectList = new ArrayList<Student>();
        for(Student s : sList){
            if(s.getId()==id){
                selectList.add(s);
            } 
        }
        return selectList;
    }

    //添加
    @ResponseBody
    @RequestMapping(value="/student",method=RequestMethod.POST)
    public Object post(@RequestBody Student student){
        System.out.println("POST:"+student.getId());
        sList.add(student);
        return sList;
    }

    //修改
    @ResponseBody
    @RequestMapping(value="/student/{id}",method=RequestMethod.PUT)
    public Object put(@PathVariable("id") Integer id,@RequestBody Student student){
        System.out.println("PUT:"+id);
        List<Student> removeList = new ArrayList<Student>();
        for (Student s : sList) {
            if(s.getId()==id){
                student.setId(s.getId());
                removeList.add(s);  
            }
        }
        sList.removeAll(removeList);
        sList.add(student);
        return sList;
    }

    //删除所有
    @ResponseBody
    @RequestMapping(value="/student",method=RequestMethod.DELETE)
    public Object delete(){
        System.out.println("DELETE:ALL");
        sList.clear();
        return sList;
    }

    //删除单个
    @ResponseBody
    @RequestMapping(value="/student/{id}",method=RequestMethod.DELETE)
    public Object delete(@PathVariable("id") Integer id){
        System.out.println("DELETE:"+id);
        List<Student> removeList = new ArrayList<Student>();
        for (Student s : sList) {
            if(s.getId()==id){
                removeList.add(s);  
            }
        }
        sList.removeAll(removeList);
        return sList;
    }
}

6.利用postman测试接口(本例子是仿造学生表的增删改查)：
(1)GET查询所有：localhost:8080/springmvc/rest/student

(2)GET查询单个：localhost:8080/springmvc/rest/student/2017001

(3)POST提交单个（先设置好类型和json数据）：localhost:8080/springmvc/rest/student



(4)PUT修改单个（先设置好类型和json数据）：localhost:8080/springmvc/rest/student/2017004



(5)DELETE删除单个：localhost:8080/springmvc/rest/student/2017001

(5)DELETE删除所有：localhost:8080/springmvc/rest/student

源码：
http://download.csdn.net/download/m0_37459945/10165177
https://github.com/15629168655/springmvc-rest-json
参考：
http://blog.csdn.net/xinyuan_java/article/details/46696703
http://blog.csdn.net/w605283073/article/details/51338765
https://www.cnblogs.com/cnblog-long/p/6547380.html
http://blog.csdn.net/lutinghuan/article/details/46820023
http://blog.csdn.net/lzj3462144/article/details/76980779?foxhandler=RssReadRenderProcessHandler