如何在 Zuul post filter 中拦截和编辑响应体？

Question

我正在使用 Zuul post filter 来拦截响应。我的要求是向响应 json 添加一个新字段。我能够拦截响应并对其进行编辑。但是，无法将更新后的响应设置为 RequestContext。在后过滤器中使用 Zuul 作为代理时，如何读取响应主体、编辑并将其更新回 RequestContext？

请找到我正在使用的以下代码。

private void updateResponseBody(RequestContext ctx) throws IOException, JSONException {

    final InputStream responseDataStream = ctx.getResponseDataStream();

    String responseData = CharStreams.toString(new InputStreamReader(responseDataStream, "UTF-8"));

    JSONObject jsonObj = new JSONObject(responseData);

    JSONArray groupsArray = jsonObj.getJSONArray("list");

    for (int i = 0; i < groupsArray.length(); i++) {

        JSONObject groupId = groupsArray.getJSONObject(i);

        groupId.accumulate("new_json_field_name", "new_json_field_value");

    }

    String updatedResponse = jsonObj.toString();

    // ctx.setResponseBody(body); // also not working

    ctx.setResponseDataStream(org.apache.commons.io.IOUtils.toInputStream(updatedResponse, "UTF-8"));

}

我得到的错误是：

Error while sending response to client: java.io.IOException: An existing connection was forcibly closed by the remote host.

谁能帮我解决这个问题。

Answer 1

我遇到了同样的错误，疯狂地修改了How to get response body in Zuul post filter? 中描述的代码。尝试不同的可能性。最后，我在这篇文章中找到了解决方案，方法是在OutputStreamfromservletResponse.getOutputStream()而不是 中写下答案ctx.setResponseDataStream()：HttpServletResponse servletResponse = ctx.getResponse();&nbsp; ...String updatedResponse = jsonObj.toString();try {&nbsp; &nbsp; OutputStream outStream = servletResponse.getOutputStream();&nbsp; &nbsp; outStream.write(updatedResponse.getBytes(), 0, updatedResponse.length());&nbsp; &nbsp; outStream.flush();&nbsp; &nbsp; outStream.close();} catch (IOException e) {&nbsp; &nbsp; log.warn("Error reading body", e);}

Answer 2

我有一个类似的任务，并试图通过写入 OutputStream 来完成。这有效，但有一个奇怪的副作用，它使响应中的 HttpHeaders 被删除或损坏。这使得调用在生产中产生 CORS 错误，即使它通过 Postman 在本地运行良好。我编写了以下方法，我从我的 Post Zuul 过滤器的 run() 方法调用该方法以将单个节点/值添加到返回的 Json。&nbsp; &nbsp; private void addJsonNode(RequestContext requestContext,String name, String id) {&nbsp; &nbsp; &nbsp; &nbsp; HttpServletResponse servletResponse = requestContext.getResponse();&nbsp; &nbsp; &nbsp; &nbsp; try {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; final InputStream responseDataStream = requestContext.getResponseDataStream();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; String responseData = CharStreams.toString(new InputStreamReader(responseDataStream, "UTF-8"));&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; JSONObject jsonObject = new JSONObject(responseData);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; jsonObject.put(name, id);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; String updatedResponse = jsonObject.toString(4);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; requestContext.setResponseBody(updatedResponse);&nbsp; &nbsp; &nbsp; &nbsp; } catch (IOException e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; log.warn("Error reading body", e);&nbsp; &nbsp; &nbsp; &nbsp; } catch (JSONException e) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; log.warn("Error reading body", e);&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }