Android HTTP 客户端卡住

Question

我在 HTTP 请求中遇到了一些奇怪的行为。我有一些用户说这个调用永远不会回来(标记它是异步调用的微调器永远不会消失)。我以前见过这种情况，但我将其归因于模拟器通过 Charles Proxy。直到现在我还没有在实际手机上看到它。

我不确定是什么原因会导致这种情况发生，这就是我将其发布在这里的原因。这是调用，使用 Jackson 将结果反序列化为值对象。我看到模拟器卡住的两个地方是 httpclient.execute(httpGet);和 getObjectMapper().readValue(jp, SyncVO.class);.

在调试时，单步跳过有问题的语句会导致调试器永远无法控制回单步执行。同时，我看到请求发出并通过 Charles 从服务器返回。只是应用程序似乎没有得到响应，只是坐在那里。

所以，这是代码。感谢您的帮助!

public SyncVO sync(String userId, long lastUpdate, boolean includeFetch) throws IOException {
    SyncVO result = null;

    String url = BASE_URL + "users/" + userId + "/sync" + "?" + "fetch=" + includeFetch;

    if (lastUpdate > 0) {
        url += "&updatedSince=" + lastUpdate;
    }

    DefaultHttpClient httpclient = new DefaultHttpClient();
    HttpGet httpGet = new HttpGet(url);

    httpGet.setHeader("Accept", "application/json");
    httpGet.setHeader("Accept-Encoding", "gzip");
    httpGet.setHeader(AUTHORIZATION, BEARER + " " + mOAuthToken);
    httpclient.getParams().setParameter(CoreProtocolPNames.USER_AGENT, USER_AGENT_STRING);
    httpclient.getParams().setBooleanParameter(CoreProtocolPNames.USE_EXPECT_CONTINUE, false);

    HttpResponse response = httpclient.execute(httpGet);

    if (isUnauthorized(response)) {
        APPLICATION.needReauthentication();
        return null;
    }

    if (response != null) {
        InputStream stream = response.getEntity().getContent();
        Header contentEncoding = response.getFirstHeader("Content-Encoding");
        if (contentEncoding != null && contentEncoding.getValue().equalsIgnoreCase("gzip")) {
            stream = new GZIPInputStream(stream);
        }

        InputStreamReader inReader = new InputStreamReader(stream, "UTF-8");
        JsonParser jp = mJsonFactory.createJsonParser(inReader);
        result = getObjectMapper().readValue(jp, SyncVO.class);
    }   

    return result;
}

private ObjectMapper getObjectMapper() {
    return (new ObjectMapper()
        .configure(Feature.AUTO_DETECT_FIELDS, true)
        .configure(Feature.FAIL_ON_UNKNOWN_PROPERTIES, false)
        .configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true));
}

Answer 1

不要忘记在每次请求后消费实体内容。

HttpEntity entity = response.getEntity();
  try {
   if (entity != null)
    entity.consumeContent();
  } catch (IOException e) {
   e.printStackTrace();
  }