Android：如何每10秒通过服务发送一次HTTP请求

Question

我需要每10秒从服务器收到一个状态。

我试图通过服务发送一个http请求来做到这一点。

问题是我的代码只能执行一次。

这是我的服务代码：

public class ServiceStatusUpdate extends Service {

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

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    while(true)
    {
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            new DoBackgroundTask().execute(Utilities.QUERYstatus);
            e.printStackTrace();
        }
        return START_STICKY;            
    }
}

private class DoBackgroundTask extends AsyncTask<String, String, String> {

    @Override
    protected String doInBackground(String... params) {
        String response = "";
        String dataToSend = params[0];
        Log.i("FROM STATS SERVICE DoBackgroundTask", dataToSend);
        HttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(Utilities.AGENT_URL);

        try {
            httpPost.setEntity(new StringEntity(dataToSend, "UTF-8"));

            // Set up the header types needed to properly transfer JSON
            httpPost.setHeader("Content-Type", "application/json");
            httpPost.setHeader("Accept-Encoding", "application/json");
            httpPost.setHeader("Accept-Language", "en-US");

            // Execute POST
            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity responseEntity = httpResponse.getEntity();
            if (responseEntity != null) {
                response = EntityUtils.toString(responseEntity);
            } else {
                response = "{\"NO DATA:\"NO DATA\"}";
            }
        } catch (ClientProtocolException e) {
            response = "{\"ERROR\":" + e.getMessage().toString() + "}";
        } catch (IOException e) {
            response = "{\"ERROR\":" + e.getMessage().toString() + "}";
        }
        return response;
    }

    @Override
    protected void onPostExecute(String result) {
        Utilities.STATUS = result;
        Log.i("FROM STATUS SERVICE: STATUS IS:", Utilities.STATUS);
        super.onPostExecute(result);
    }
}
}

谢谢很多阿维

Answer 1

将处理程序放入onPostExecute中以在10秒后发送http请求

new Handler().postDelayed(new Runnable() {
        public void run() {
            requestHttp();
        }
    }, 10000);

10秒后，将再次执行doInBackground，然后再次执行onPostExecute，再次处理程序，依此类推。