如何在Spring REST控制器中获取原始JSON主体

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。如何将请求正文(email(作为原始字符串获取？(我想要原始字符串和键入的email参数版本(

PS：这个问题不是：如何在Spring rest控制器中访问纯json主体？

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

Answer 1

您可以用多种方式来实现，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);
}

Answer 2

Spring在后面使用Jackson，您可以使用它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 3

我并没有完全了解这个问题，但我试着根据自己的理解来回答。好如果您想获得请求正文：

• 正如您所说，如何在Spring rest控制器中访问纯json主体？这里已经写了如何做到这一点。如果出现问题，可能是您发送了错误的json或不适合的类型，正如您在Email类中看到的那样。也许你的请求来自url过滤器

• 第二种方法：

  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);
  }
  

如果您想将对象转换为json字符串，请阅读这篇文章

Answer 4

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);
}