如何在 Spring REST 控制器中获取原始 JSON 正文？

Question

下面的 API 接受来自客户端的 json 字符串，并将其映射到电子邮件对象中。如何获取请求正文 (email) 作为原始字符串？ （我想要email 参数的原始字符串和类型版本）

PS：这个问题不是重复的：How to access plain json body in Spring rest controller?

@PostMapping(value = "/mailsender")
public ResponseEntity<Void> sendMail(@RequestBody Email email) {
    //...
    return new ResponseEntity<>(HttpStatus.OK);
}

Answer 1

Spring 在后面为此使用了 Jackson，您可以使用它来将其序列化为字符串。像这样：

@Autowired private ObjectMapper jacksonMapper;

@PostMapping(value = "/mailsender")
public ResponseEntity<Void> sendMail(@RequestBody Email email) {
    //...
    log.info("Object as String: " + jacksonMapper.writeValueAsString(email));
    return new ResponseEntity<>(HttpStatus.OK);
}

Answer 2

您可以使用 GSON 库创建字符串类型的 json

Gson gson = new Gson();

@PostMapping(value = "/endpoint")
public ResponseEntity<Void> actionController(@RequestBody Car car) {
    //...
    log.info("Object as String: " + this.gson.toJson(car));
    return new ResponseEntity<>(HttpStatus.OK);
}

Answer 3

我没有得到关于这个问题的所有信息，但我试着按照我的理解来回答。好吧， 如果您想获取请求正文：

• 正如你所说的How to access plain json body in Spring rest controller? 这里已经写了如何做到这一点。如果出现问题，可能您在Email 类中发送了错误的 json 或不合适的类型。也许您的请求来自 url 过滤器

• 第二种方法试试这样：

  private final ObjectMapper mapper = new ObjectMapper();
  
  @PostMapping(value = "/mailsender")
  public ResponseEntity<Void> sendMail(HttpServletRequest req) {
      // read request body
      InputStream body = req.getInputStream();        
      byte[] result = ByteStreams.toByteArray(body);
      String text =new String(result,"UTF-8");
      //convert to object
      Email email = mapper.readValue(body, Email .class);
      return new ResponseEntity<>(HttpStatus.OK);
  }
  
  

如果要将对象转换为json字符串read this post

Answer 4

你可以用不止一种方法，列出两种

 1. **Taking string as the paramater**,
     @PostMapping(value = "/mailsender")
        public ResponseEntity<Void> sendMail(@RequestBody String email) {
            //... the email is the string can be converted to Json using new JSONObject(email) or using jackson.
            return new ResponseEntity<>(HttpStatus.OK);
        }

 2. **Using Jackson** 
         @PostMapping(value = "/mailsender")
            public ResponseEntity<Void> sendMail(@RequestBody Email email) {
                //...
                ObjectMapper mapper = new ObjectMapper(); 
                String email = mapper.writeValueAsString(email); //this is in string now
                return new ResponseEntity<>(HttpStatus.OK);
            }