如何在Spring Boot @ResponseBody中返回404响应状态 - 方法返回类型是Response？

Question

我正在使用Spring Boot和基于@ResponseBody的方法,如下所示:

@RequestMapping(value = VIDEO_DATA_PATH, method = RequestMethod.GET)
public @ResponseBody Response getData(@PathVariable(ID_PARAMETER) long id, HttpServletResponse res) {
    Video video = null;
    Response response = null;
    video = videos.get(id - 1);
    if (video == null) {
      // TODO how to return 404 status
    }
    serveSomeVideo(video, res);
    VideoSvcApi client =  new RestAdapter.Builder()
            .setEndpoint("http://localhost:8080").build().create(VideoSvcApi.class);
    response = client.getData(video.getId());
    return response;
}

public void serveSomeVideo(Video v, HttpServletResponse response) throws IOException  {
    if (videoDataMgr == null) {
        videoDataMgr = VideoFileManager.get();
    }
    response.addHeader("Content-Type", v.getContentType());
    videoDataMgr.copyVideoData(v, response.getOutputStream());
    response.setStatus(200);
    response.addHeader("Content-Type", v.getContentType());
}

}

我尝试了一些典型的方法:

res.setStatus(HttpStatus.NOT_FOUND.value());
新的ResponseEntity(HttpStatus.BAD_REQUEST);

但我需要返回Response.

如果视频为空,如何返回404状态代码？

Answer 1

创建一个NotFoundException带@ResponseStatus(HttpStatus.NOT_FOUND)注释的类,并从控制器中抛出它.

@ResponseStatus(code = HttpStatus.NOT_FOUND, reason = "video not found")
public class VideoNotFoundException extends RuntimeException {
}

Answer 2

这很简单，只需抛出org.springframework.web.server.ResponseStatusException即可：

throw new ResponseStatusException(
  HttpStatus.NOT_FOUND, "entity not found"
);

它与@ResponseBody和任何返回值兼容。需要春季5+

Answer 3

您的原始方法可以返回ResponseEntity(不会更改您的方法行为):

@RequestMapping(value = VIDEO_DATA_PATH, method = RequestMethod.GET)
public ResponseEntity getData(@PathVariable(ID_PARAMETER) long id, HttpServletResponse res{
... 
}

并返回以下内容:

return new ResponseEntity(HttpStatus.NOT_FOUND);

Answer 4

您可以像这样在 res 上设置 responseStatus ：

@RequestMapping(value = VIDEO_DATA_PATH, method = RequestMethod.GET)
public ResponseEntity getData(@PathVariable(ID_PARAMETER) long id,
                                            HttpServletResponse res) {
...
    res.setStatus(HttpServletResponse.SC_NOT_FOUND); 
    // or res.setStatus(404)
    return null; // or build some response entity
 ...
}