SpringBoot接收前端参数json格式的五种方式

import java.util.List;
import java.util.Map;
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.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import com.alibaba.fastjson.JSONObject;
 
@RestController
public class HelloController2 {
 
    /*
     * 第一种：以RequestParam接收
     * http://localhost:8080/test1?id=1
     * */
    @RequestMapping(value = "/test1",method=RequestMethod.GET)
    public void test1(@RequestParam("id") String id){
        System.out.println("id:"+id);    
    }
    
    /*
     * 第二种：以实体类接收
     * {"username": "zhangsan","id":"2"}
     * */
    @RequestMapping(value = "/test2",method=RequestMethod.POST)
    public void test1(@RequestBody User user) throws Exception{
        System.out.println("username:"+user.getUsername());    
    }
    
    /*
     * 第三种：以Map接收
     * {"username": "zhangsan","id":"2"}
     * */
    @RequestMapping(value = "/test3",method=RequestMethod.POST)
    public void test3(@RequestBody Map<String, String> map) throws Exception{
        System.out.println("username:"+map.get("username"));    
    }
    
    /*
     * 第四种：以List接收
     * [{"username": "zhangsan","id":"2"},{"username": "lisi","id":"1"}]
     * */
    @RequestMapping(value = "/test4",method=RequestMethod.POST)
    public void test4(@RequestBody List<User> list) throws Exception{
        for(User user:list){
            System.out.println("username:"+user.getUsername());
        }
    }
    
    /*
     * 第五种：以JSON对象接收
     * {"username": "zhangsan","id":"2","role":{"rolename":"admin"}}
     * */
    @RequestMapping(value = "/test5",method=RequestMethod.POST)
    public void test5(@RequestBody JSONObject json) throws Exception{
        System.out.println("username:"+json.getString("username"));    
        System.out.println("rolename:"+json.getJSONObject("role").getString("rolename"));
    }}