json - 找不到可接受的代表

Question

我是 Spring Boot 的新手，我可能会犯一些愚蠢的错误，所以提前对此类问题表示歉意。 我正在尝试编写接受以下 JSON 的 POST API:

{
  "id" : null,
  "a": 1.3,
  "b": "somestring",
   "mapJson" : 
    { 
        "monday" : "10:00-12:00/n14:00-18:00", 
        "tuesday" : "10:00-12:00/n14:00-18:00",
        "wednesday" : "10:00-12:00/n14:00-18:00",
        "thursday" : "10:00-12:00/n14:00-18:00",
        "friday" : "10:00-12:00/n14:00-18:00",
        "saturday" : "10:00-12:00/n14:00-18:00",
        "sunday" : "10:00-12:00/n14:00-18:00"
    },
    "list" : ["cc","paytm","debit"]
}

考虑以下 DTO 类，AbcDTO:

package com.abb.dto;
import java.util.List;
import com.abb.entities.OpeningHrs;
import lombok.Data;

@SuppressWarnings("unused")
@Data
public class AbcDTO {

    private Long id;
    private Double a;
    private String b;
    private MapJson mapJson;
    private List<String> list;

}

OpeningHrs是映射Json Map结构的类，

package com.abb.entities;
import lombok.Data;
@SuppressWarnings("unused")
@Data
public class MapJson {

    private String monday;
    private String tuesday;
    private String wednesday;
    private String thursday;
    private String friday;
    private String saturday;
    private String sunday;

}

AbcController 具有 Post API:

package com.abb.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
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;
import org.springframework.web.bind.annotation.RestController;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.abb.dto.AbcDTO;

@RestController
@EnableAutoConfiguration
@RequestMapping("/abc")
@GetMapping(value="/{id}",produces={MediaType.APPLICATION_JSON_VALUE})
public class HotelController {

   @RequestMapping(value = "/xyz", method = RequestMethod.POST)
    public @ResponseBody AbcDTO registerHotel(@RequestBody AbcDTO aaa) {

       System.out.println(aaa.toString());
       return aaa; 
   // I'm not able to map JSON into this Object
    }

}

请查找我收到的以下回复:

{
    "timestamp": 1509193409948,
    "status": 406,
    "error": "Not Acceptable",
    "exception": "org.springframework.web.HttpMediaTypeNotAcceptableException",
    "message": "Could not find acceptable representation",
    "path": "/abc/xyz"
}

Answer 1

POST 请求不起作用，因为 Spring 不知道它需要什么类型的数据。因此，您需要告诉 spring 您正在等待 APPLICATION_JSON_VALUE，以便它知道如何处理。正如您可能猜到的那样，consumes= 将告诉 Spring 传入的 POST 主体上下文类型是什么。

@RequestMapping(value = "xyz", method = RequestMethod.POST, consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
public @ResponseBody AbcDTO registerHotel(@RequestBody AbcDTO aaa) {

    System.out.println(aaa.toString());
    return aaa; 
    // I'm not able to map JSON into this Object
}

使用 PostMapping

@PostMapping(value = "xyz", consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
public @ResponseBody AbcDTO registerHotel(@RequestBody AbcDTO aaa) {

   System.out.println(aaa.toString());
   return aaa; 
   // I'm not able to map JSON into this Object
}

如您所见，我还添加了其他名称，products=，这将指示 Spring 如何格式化该请求的响应正文。因此前端接收 JSON 格式的正文，而不仅仅是随机文本。