SpringBoot 前后传值汇总

###正在建设的项目中遇到了关于前后端传值的问题，现在汇总成一个Blog，方便以后翻阅
传递字符串

// SpringBoot 后端
@PostMapping(value = "/URL")
public String select(@RequestParam("KEY") String key) ~~throws IOException~~  {

//AJAX前端
$.ajax({
	url:"URL",
	type:"POST",
	data:{KEY:VALUE},
	dataType:"JSON",
	success:function (data) {
			
	}
})

传递对象

// SpringBoot 后端
@RequestMapping(value = "/sendMail", method = RequestMethod.POST)
@ResponseBody
public String snoLogin(@RequestBody User user) {
    }

//AJAX前端
$.ajax({
     url: "sendMail",
     type: "POST",
     data: JSON.stringify({user: user}),
     contentType: "application/json;charset=UTF-8",
     dataType: "text",
     success: function (data) {
                
     }
});

可以使用自定对象进行传值，以下内容转载至https://yremp.live/spring-boot-ajax/

 function submit(){
        var username = $("#username").val();
        var password = $("#password").val();
        var list ={
            username: username,
            password: password
        };
        $.ajax({
            //请求方式
            type: "POST",
            //请求的媒体类型
            contentType: "application/json;charset=UTF-8",
            //请求地址
            url: "/user/json",
            //数据，json字符串
            data: JSON.stringify(list),
            //请求成功
            success: function (res) {
               if (res.status === 200) {
                    console.log(res);
                } else {
                }
            }
        });
 
    }

@Controller
public class IndexController {
    @RequestMapping("/")
    public String index(){
        return "login.html";
    }
 
    @PostMapping("/user/json")
    @ResponseBody
    public JSONObject user(@RequestBody JSONObject user){
        String username = user.get("username").toString();
        String password = user.get("password").toString();
        System.out.println("使用JSONObject接收：");
        System.out.println("用户名："+username);
        System.out.println("密码："+password);
        JSONObject result = new JSONObject();
        result.put("status",200);
        result.put("message","服务端已经收到请求");
        return result;
    }
 
    @PostMapping("/user/dto")
    @ResponseBody
    public JSONObject user(@RequestBody UserDTO user){
        String username = user.getUsername();
        String password      = user.getPassword();
        System.out.println("使用自定义的DTO接收：");
        System.out.println("用户名："+username);
        System.out.println("密码："+password);
        JSONObject result = new JSONObject();
        result.put("status",200);
        result.put("message","服务端已经收到请求");
        return result;
    }
}
//实体类
public class UserDTO {
    private String username;
    private String password;
 
    public String getUsername() {
        return username;
    }
 
    public void setUsername(String username) {
        this.username = username;
    }
 
    public String getPassword() {
        return password;
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
}

END