check if the server is available?

问题

I developing an application which connects to the server. Therefore i want use the bellow function to check if the server is available , But I don't know how I can use it in a thread and how call it each time when I need check if the server is available in activity or fragment :

static public boolean isURLReachable(Context context) {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    if (netInfo != null && netInfo.isConnected()) {
        try {
            URL url = new URL("http://192.168.1.13");   // Change to "http://google.com" for www  test.
            HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
            urlc.setConnectTimeout(10 * 1000);          // 10 s.
            urlc.connect();
            if (urlc.getResponseCode() == 200) {        // 200 = "OK" code (http connection is fine).
                Log.wtf("Connection", "Success !");
                return true;
            } else {
                return false;
            }
        } catch (MalformedURLException e1) {
            return false;
        } catch (IOException e) {
            return false;
        }
    }
    return false;
}

回答1:

Take a look at this code:

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);     
    ConnectivityManager cm = (ConnectivityManager)  getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    if (netInfo != null && netInfo.isConnected()) {
        MyTask task = new MyTask();
        task.execute();
    }
}


private class MyTask extends AsyncTask<Void, Void, Boolean> {

    @Override
    protected void onPreExecute() {

    }

    @Override
    protected Boolean doInBackground(Void... params) {

         try {

        URL url = new URL("http://192.168.1.13");   // Change to "http://google.com" for www  test.
        HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
        urlc.setConnectTimeout(10 * 1000);          // 10 s.
        urlc.connect();
        if (urlc.getResponseCode() == 200) {        // 200 = "OK" code (http connection is fine).
            Log.wtf("Connection", "Success !");
            return true;
        } else {
            return false;
        }
    } catch (MalformedURLException e1) {
        return false;
    } catch (IOException e) {
        return false;
    }
 }

    @Override
    protected void onPostExecute(Boolean result) {
        boolean bResponse = result;
         if (bResponse==true)
            {
                Toast.makeText(MainActivity.this, "server is available", Toast.LENGTH_SHORT).show();      
            }
            else
            {           
                Toast.makeText(MainActivity.this, "server is not available", Toast.LENGTH_SHORT).show();
            }                  
      }           
   }
}

回答2:

You can use just AsyncTask (http://developer.android.com/guide/components/processes-and-threads.html)

Its the android way to run short asynchronous tasks in background, And it has a callback method when finished

来源：https://stackoverflow.com/questions/28856106/check-if-the-server-is-available

标签

android

networking

connectivity