我有一些简单的问题。
我可以仅使用 AsyncTask 在 java 上进行长轮询吗?
class makepolling extends AsyncTask<String, String, String> {
String TAG = "AndroidPolling";
int CONNECTION_TIMEOUT = 900000;
int mHeartbeat = 10000;
int TIMEOUT_TOLERANCE = 5000;
String mPushURL = "https://my_serv_adress/service";
@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);
HttpPost httpPost = new HttpPost(mPushURL);
httpPost.addHeader("Accept", "application/json");
try {
Log.i(TAG, "Executing POST(PUSH) request " + httpPost.getRequestLine());
HttpResponse httpResponse = def.execute(httpPost);
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;
}
当响应返回超时时,我如何再次发出请求?
此致。
抱歉我的英语不好
最佳答案
AsyncTasks
用于相对较短的操作,因此如果您想要进行一些长轮询,您可能应该尝试不同的方法。如果您想定期进行网络调用,您可以在后台运行一个 Service
。
下面的代码可能对您有帮助。它只是每 10 秒执行一次的服务模板。请记住,网络调用需要在 UI 线程之外完成:
public class MyService extends Service {
private IBinder mBinder = new SocketServerBinder();
private Timer mTimer;
private boolean mRunning = false;
@Override
public void onCreate() {
super.onCreate();
mTimer = new Timer();
mTimer.schedule(new TimerTask() {
@Override
public void run() {
if (mRunning) {
// make your network call here
}
}
}, 10000, 10000);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
mRunning = true;
return super.onStartCommand(intent, flags, startId);
}
@Override
public IBinder onBind(Intent arg0) {
mRunning = true;
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
mRunning = false;
return super.onUnbind(intent);
}
public class SocketServerBinder extends Binder {
public MyService getService() {
return MyService.this;
}
}
}
关于java - Android长轮询技术,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20800189/