Android长轮询 - 超时执行服务

Question

我想在我的Android应用程序中实现LongPolling。 Long Polling

如果LongPolling需要很长时间才能得到答案，我的android服务崩溃。

我尝试过使用线程和异步。一般来说，我尝试了很多员工，但我没有得到它。

public class PollingService extends Service { 

String TAG = "AndroidPolling"; 
int CONNECTION_TIMEOUT = 900000; 
int mHeartbeat = 10000; 
int TIMEOUT_TOLERANCE = 5000; 
String mPushURL = "http://192.168.0.115:8080/de.test.jersey.cti/rest/todos/"; 


@Override 
public void onCreate() { 
    super.onCreate();  
    Log.i(TAG, "RestService Service-Class created"); 

} 

    public void onStart(Intent intent, int startId) { 
    Log.i(TAG, "onStart"); 

    new makepolling().doInBackground("http://192.168.0.115:8080/de.test.jersey.cti/rest/todos/"); 

} 


@Override 
public IBinder onBind(Intent intent) { 
    // TODO Auto-generated method stub 
    return null; 
} 
} 

---

class makepolling extends AsyncTask<String, String, String> { 

String TAG = "AndroidPolling"; 
int CONNECTION_TIMEOUT = 900000; 
int mHeartbeat = 10000; 
int TIMEOUT_TOLERANCE = 5000; 
String mPushURL = "http://192.168.0.115:8080/de.test.jersey.cti/rest/todos/"; 

@Override 
protected String doInBackground(String... arg0) { 
    String result = null; 
    DefaultHttpClient def = new DefaultHttpClient(); 
    HttpParams httpParams = def.getParams(); 
    HttpConnectionParams.setConnectionTimeout(httpParams, CONNECTION_TIMEOUT); 

    ConnManagerParams.setTimeout(httpParams, CONNECTION_TIMEOUT); 
    HttpGet httpGet = new HttpGet(mPushURL); 
    httpGet.addHeader("Accept", "application/json"); 

    try { 
     Log.i(TAG, "Executing GET(PUSH) request " + httpGet.getRequestLine()); 

     HttpResponse httpResponse = def.execute(httpGet); 
     Log.i(TAG, result); 
     Log.i(TAG, String.valueOf(httpResponse.getProtocolVersion())); 
     Log.i(TAG, String.valueOf(httpResponse.getEntity().getContent())); //For testing purposes 


    } catch (ClientProtocolException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    return result; 

} 

@Override 
protected void onPostExecute(String result) { 
    // TODO Auto-generated method stub 

    super.onPostExecute(result); 
} 

} 

Answer 1

你不应该调用doInBackground（）明确。要启动一个AsyncTask，你必须创建它的一个实例并在其上调用execute（）方法。 This文章很好地解释了AsyncTask。