java - 使用 Spring RestTemplate 遵循 302 重定向？

Question

  RestTemplate restTemplate = new RestTemplate();

  final MappingJackson2XmlHttpMessageConverter converter = new MappingJackson2XmlHttpMessageConverter();
  final List<MediaType> supportedMediaTypes = new LinkedList<MediaType>(converter.getSupportedMediaTypes());
  supportedMediaTypes.add(MediaType.ALL);
  converter.setSupportedMediaTypes(supportedMediaTypes);
  restTemplate.getMessageConverters().add(converter);  


  ResponseEntity<MyDTO[]> response = restTemplate.getForEntity(urlBase, MyDTO[].class);

  HttpHeaders headers = response.getHeaders();
  URI location = headers.getLocation(); // Has my redirect URI

  response.getBody(); //Always null

我的印象是 302 会自动被跟随。我的这个假设不正确吗？我现在需要选择这个位置并重新请求？

Answer 1

使用默认的ClientHttpRequestFactory实现 - 即 SimpleClientHttpRequestFactory - 默认行为是遵循位置 header 的 URL(对于状态代码 3xx 的响应) - 但前提是初始请求是 GET 请求。

详细信息可以在此类中找到 - 搜索以下方法:

protected void prepareConnection(HttpURLConnection connection, String httpMethod) throws IOException {

    ...

    if ("GET".equals(httpMethod)) {
        connection.setInstanceFollowRedirects(true);
    }

这里是HttpURLConnection.setInstanceFollowRedirects方法的相关文档注释:

Sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this {@code HttpURLConnection} instance.

The default value comes from followRedirects, which defaults to true.