java - 如何从 HttpURLConnection 创建 ResponseEntity？

Question

我想将 HttpURLConnection 的响应检索到 ResponseEntity 中。我收到 406 错误。

提前谢谢您。

@RequestMapping(value = "/retrive", method = { RequestMethod.GET })
    public ResponseEntity<?> retrive (HttpServletRequest request){
        //1. call a rest by rest client
        URL u = new URL("http://localhost:8080/getHello");
        HttpURLConnection uc = (HttpURLConnection) u.openConnection();

        //2, create HttpHeaders for ResponseEntity
        HttpHeaders responseHeaders = new HttpHeaders();
        for (int i = 0;; i++) {
          String headerName = uc.getHeaderFieldKey(i);
          String headerValue = uc.getHeaderField(i);
          if(headerName != null && headerValue != null){
            responseHeaders.set(headerName, headerValue);
          }
          if (headerName == null && headerValue == null) {
            break;
          }
        }
        //3. create ResponseEntity
        InputStream inputStream = uc.getInputStream();
        return new ResponseEntity<>(inputStream, responseHeaders, HttpStatus.OK);
    }

Answer 1

假设您正在尝试构建某种反向代理，那么您只需从输入流复制到输出流即可:

  @RequestMapping(value = "/retrive", method = { RequestMethod.GET })
  public ResponseEntity<?> retrive (HttpServletRequest request, HttpServletResponse response){
    //1. call a rest by rest client
    URL u = new URL("http://localhost:8080/getHello");
    HttpURLConnection uc = (HttpURLConnection) u.openConnection();

    //2, create HttpHeaders for ResponseEntity
    HttpHeaders responseHeaders = new HttpHeaders();
    for (int i = 0;; i++) {
      String headerName = uc.getHeaderFieldKey(i);
      String headerValue = uc.getHeaderField(i);
      if(headerName != null && headerValue != null){
        responseHeaders.set(headerName, headerValue);
      }
      if (headerName == null && headerValue == null) {
        break;
      }
    }

    try (InputStream inputStream = uc.getInputStream();
         OutputStream outputStream = response.getOutputStream();
        )
    {
      IOUtils.copy(inputStream, outputStream);
    }
    //3. create ResponseEntity
    return new ResponseEntity<>(responseHeaders, HttpStatus.OK);
  }