ANDROID Check condition for server down

问题:

My app needs to check for internet access which I successfully implemented. But I have a condition that internet is available but website it is trying to open is currently down. In this case I need to show different message as an output. How can I do so? Please give some idea.

回答1:

public boolean isServerReachable()
    // To check if server is reachable
    {
        try {
            InetAddress.getByName("google.com").isReachable(3000); //Replace with your name
            return true;
        } catch (Exception e) {
            return false;
        }
    }

回答2:

You should check the status of the website's response Like this:

HttpResponse response = httpClient.execute(request);
        int status = response.getStatusLine().getStatusCode();

and check here to find your status code.
then you can do your job by checking status code like this:

if (status == 200) // sucess
        {

also I recommend you to use AsyncTask for your connection to do communication with server in background.

回答3:

Try to catch NoHttpResponseException as follow

try{
//code to try to connect to your server

}catch(NoHttpResponseException ex){
//print stacktrace or display some message to say server is down
}

回答4:

You can use this class. Make object and call methods.

    public class ConnectionDetector {

    private Context context;

    public ConnectionDetector(Context context){
        this.context = context;
    }

    public boolean isConnectingToInternet(){
        ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivity != null)
        {
            NetworkInfo[] info = connectivity.getAllNetworkInfo();
            if (info != null)
                for (int i = 0; i < info.length; i++)
                    if (info[i].getState() == NetworkInfo.State.CONNECTED)
                    {
                        return true;
                    }

        }
        return false;
    }

   public boolean isURLReachable() {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
        if (netInfo != null && netInfo.isConnected()) {
            try {
                URL url = new URL(serverConnection.url);   // Insert Url
                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;
    }
}