Question

My Android game needs to get some information about players from my server. I do this with a simple HTTP GET request, which I placed inside a thread.

The code I am using is below. When my server is up and running the app works fine. When my server is not responding (either because it’s busy or down), however, the app crashes.

Instead of the app crashing I would like to display a “Network is busy” message to the user and send him back to the main activity, but not sure how to do it.

I tried to create a dialog inside the Catch section, thinking this would show if my server was down, but it’s not showing and the app crashes.

Any ideas how I can solve this?

public void run(){      
        String urlstring = "http://www.mydomain.com/?param=test"; 
        try{                        
                URL url = new URL(urlstring);
                HttpURLConnection con = (HttpURLConnection) url.openConnection();
                BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
                line = reader.readLine();   
        }
        catch(Exception e){
            Dialog d2 = new Dialog(context);
            d2.setContentView(R.layout.dialog2);
            d2.show();
        } 
}

Update: I think I found the issue looking at logcat. Even with the server down my BufferedReader was returning an empty string, and I was trying to use that down the road.

Answer 1

So at first, you should check your response. This is best approach

if (urlConntection.getResponseCode() == HttpURLConnection.HTTP_OK) {
  // method body
}
else {
   /// get some info for example with Toast or Dialog
}

You should decide to use runOnUiThread when you want to update UI from Non-UI thead

YourActivity.this.runOnUiThread(new Runnable() {
            @Override
            public void run() {

            }
        });

Or use Handler or AsyncTask

When you decide to use AsyncTask, you can simply show almost everything

protected void onProgressUpdate(String... data) {
  if(data[0].equals("error")) {
    Toast.makeText(Activity.this, "Connection is busy!", Toast.LENGTH_SHORT).show(); 
}

also simply show Dialog. It’s up to you.