示例基于
https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/http/ResponseEntity.html
编辑以添加请求中的readign标题

@RequestMapping("/handle")
public ResponseEntity<String> handle(HttpServletRequest httpRequest) {
  String userId= httpRequest.getHeader("user_id");
  HttpHeaders responseHeaders = new HttpHeaders();
  responseHeaders.set("user_id", userId);
  return new ResponseEntity<String>("Hello World", responseHeaders, HttpStatus.CREATED);
}

对于我的场景，我只需要获取用户ID，然后用它进行响应，我认为最好的方法是使用@RequestHeader（“userId”）Long userId注解。
让我们看看我最初是如何配置端点的：

@PostMapping(path = "/add-follower/{userIdForFollowing}/{currentUserId}")
public ResponseEntity<String> addFollower(@PathVariable ("userIdForFollowing") Long userIdForFollowing, @PathVariable Long currentUserId)
{
    Follow newFollow = followService.returnNewFollow(userIdForFollowing, currentUserId);
    
    newFollow = followService.saveFollowToDb(newFollow);

    return new ResponseEntity<>("Follow saved successfully", HttpStatus.OK);
}

现在，让我们看看我是如何重构端点以从头部获取id并在响应中返回它们的：

@PostMapping(path = "/add-follower")
public ResponseEntity<String> addFollower(@RequestHeader("userIdForFollowing") Long userIdForFollowing, @RequestHeader("currentUserId") Long currentUserId)
{

    Follow newFollow = followService.returnNewFollow(userIdForFollowing, currentUserId);
    newFollow = followService.saveFollowToDb(newFollow);

    //here I will add more code which should replace the String in the ResponseEntity.
    return new ResponseEntity<>("Follow saved successfully", HttpStatus.OK);
}