Android - setSoTimeout不起作用

Question

所以我遇到了一个不工作的套接字超时。我遵循了现有帖子给出的所有说明，但它仍然不起作用（我从未收到套接字超时异常）。这是我的代码：

AsyncTask<String, Void, String> task = new AsyncTask<String, Void, String>() {
   @Override
   protected String doInBackground(String... params) {
      String location = params[0];
      try {
         HttpGet httpGet = new HttpGet(location);
         HttpParams httpParameters = new BasicHttpParams();
         // Set the timeout in milliseconds until a connection is established.
         // The default value is zero, that means the timeout is not used.
         int timeoutConnection = 0;
         HttpConnectionParams.setConnectionTimeout(httpParameters,
               timeoutConnection);
         // Set the default socket timeout (SO_TIMEOUT)
         // in milliseconds which is the timeout for waiting for data.
         int timeoutSocket = 2000;
         HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
         DefaultHttpClient client = new DefaultHttpClient(httpParameters);
         Log.d(this.getClass().getSimpleName(), "STARTING CLIENT!!! ");
         HttpResponse response = client.execute(httpGet);
         Log.d(this.getClass().getSimpleName(), "CLIENT CANCELLED!!! ");
         if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            response.getEntity().writeTo(out);
            return new Scanner(out.toString()).useDelimiter("\A").next();
         } else {
            return "";
         }
      } catch (IOException e) {
         e.printStackTrace();
         return null;
      } catch (URISyntaxException e) {
         e.printStackTrace();
         return null;
      }
   }
   @Override
   protected void onPostExecute(String result) {
      try {
         // doStuff
      } catch (Exception e) {
         e.printStackTrace();
      }
   }
};
task.execute(location);

所以我应该在两秒后收到套接字超时异常，但客户端只是忽略了这一点。有什么帮助吗？

提前致谢

---

所以这里是所有代码：

public void fetch(String location) {    
    AsyncTask<String, Void, String> task = new AsyncTask<String, Void, String>() {
        @Override
        protected String doInBackground(String... params) {
            String location = params[0];
            try {
                HttpGet httpGet = new HttpGet(location);
                HttpParams httpParameters = new BasicHttpParams();
                // Set the timeout in milliseconds until a connection is established.
                // The default value is zero, that means the timeout is not used. 
                int timeoutConnection = 0;
                HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
                // Set the default socket timeout (SO_TIMEOUT) 
                // in milliseconds which is the timeout for waiting for data.
                int timeoutSocket = 2000;
                HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
                DefaultHttpClient client = new DefaultHttpClient(httpParameters);
                Log.d(this.getClass().getSimpleName(), "STARTING CLIENT!!! ");
                HttpResponse response = client.execute(httpGet);
                Log.d(this.getClass().getSimpleName(), "CLIENT CANCELLED!!! ");
                if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
                    ByteArrayOutputStream out = new ByteArrayOutputStream();
                    response.getEntity().writeTo(out);
                    return new Scanner(out.toString()).useDelimiter("\A").next();
                } else {
                    return "";
                }
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            } catch (URISyntaxException e) {
                e.printStackTrace();
                return null;
            }
        }
        @Override
        protected void onPostExecute(String result) {
            try {
                //doStuff
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    };
    task.execute(location);
}

Answer 1

不久前我遇到了类似的问题。我做了一些实验，注意到当我在模拟器中运行我的应用程序时，超时不起作用，当我在真实设备上运行它时，它确实有效。我已经用DefaultHttpClient、HttpUrlConnection和AndroidHttpClient进行了测试，这三个都显示出相同的结果;在模拟器中大约 20 秒后出现 IO异常 （UnknownHostException），无论设置的超时如何。

谷歌搜索显示，其他人也报告了超时问题：

• http://code.google.com/p/android/issues/detail?id=2409
• 安卓上的 http 连接超时不起作用
• HTTP 连接超时问题
• 使用 DefaultHTTPClient 发出 HTTPGet 请求时的套接字超时

提出的解决方案都不适合我，所以我想唯一可靠的解决方案是自己管理超时。

Answer 2

参见：https://stackoverflow.com/a/20031077/2609238

问题可能出在 Apache HTTP 客户端中。请参阅 HTTPCLIENT-1098。在 4.1.2 中修复。

超时异常会出于日志记录目的尝试反向 DNS IP。这需要额外的时间，直到实际触发异常。