Detect empty server addresses

If the app detects an empty server URL, it will change it to the default server address.

app/src/main/AndroidManifest.xml

@@ -26,7 +26,7 @@
 		android:screenOrientation="fullUser"
 		android:configChanges="orientation|screenSize"/>
 	<activity android:name=".settings.SettingsActivity"
-		android:label="@string/ui_settings"
+		android:label="@string/title_activity_settings"
 		android:screenOrientation="fullUser"
 		android:configChanges="orientation|screenSize"/>
 	</application>

app/src/main/java/com/luca0n/joguitos/pluck/activities/TriviaGameActivity.java

@@ -48,6 +48,7 @@ import butterknife.BindView;
 import butterknife.ButterKnife;
 import com.luca0n.joguitos.pluck.R;
 import com.luca0n.joguitos.pluck.exceptions.NoTriviaResultsException;
+import com.luca0n.joguitos.pluck.exceptions.InvalidServerResponseException;
 import com.luca0n.joguitos.pluck.fragments.TriviaGameErrorFragment;
 import com.luca0n.joguitos.pluck.fragments.TriviaQuestionFragment;
 import com.luca0n.joguitos.pluck.interfaces.IDownloadTriviaQuestionReceiver;
@@ -142,8 +143,9 @@ public class TriviaGameActivity extends BaseActivity
 		} else {
 			try {
 				this.game = new TriviaGame(ApiUtil.jsonToQuestionArray(json));
-			} catch (NoTriviaResultsException e) {
-				onNoTriviaResults();
+			} catch (Exception e) {
+				//onNoTriviaResults();
+				onException(e);
 				return;
 			}
 		}
@@ -190,8 +192,21 @@ public class TriviaGameActivity extends BaseActivity
 		ft.commit();
 	}
 
-	private void onNoTriviaResults() {
-		String msg = getResources().getString(R.string.error_no_trivia_results);
+	/**
+	 * Handles caught exceptions and gives feedback to alert errors to the player.
+	 * @param e The caught exception.
+	 */
+	private void onException(Exception e) {
+		// Hide the progress bar.
+		progressBar.setVisibility(View.GONE);
+		String msg;
+		if (e instanceof NoTriviaResultsException)
+			msg = getResources().getString(R.string.error_no_trivia_results);
+		else if (e instanceof InvalidServerResponseException)
+			msg = getResources().getString(R.string.error_server_response_invalid);
+		else
+			msg = getResources().getString(R.string.error_unknown);
+
 		Fragment errorFragment = TriviaGameErrorFragment.newInstance(msg);
 
 		FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

app/src/main/java/com/luca0n/joguitos/pluck/trivia/TriviaQuery.java

@@ -92,11 +92,16 @@ public class TriviaQuery implements Serializable {
 		// Load custom server URL.
 		Context c = PluckApplication.getAppContext();
 		SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(c);
-		String key = c.getResources().getString(R.string.pref_network_server);
+		String serverKey = c.getResources().getString(R.string.pref_network_server);
 		// Load default server URL in case the player did not specify a custom server URL.
 		String defaultServer = c.getResources().getString(R.string.pref_network_server_default);
+		String base = sp.getString(serverKey, defaultServer) + "?"; // append "?" to the end of the URL so we can specify GET parameters.
 
-		String base = sp.getString(key, defaultServer) + "?"; // append "?" to the end of the URL so we can specify GET parameters.
+		// Check if the custom server URL preference was empty. If it was, change it to the default URL.
+		if (base.equals("?")){
+			base = defaultServer + "?";
+			sp.edit().putString(serverKey, defaultServer).commit();
+		}
 
 		url.append(base);
 		url.append("amount=").append(this.amount);

app/src/main/java/com/luca0n/joguitos/pluck/util/ApiUtil.java

@@ -31,6 +31,7 @@ import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
+import com.google.gson.JsonSyntaxException;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;
@@ -46,6 +47,7 @@ import java.util.ArrayList;
 import com.luca0n.joguitos.pluck.R;
 import com.luca0n.joguitos.pluck.PluckApplication;
 import com.luca0n.joguitos.pluck.exceptions.NoTriviaResultsException;
+import com.luca0n.joguitos.pluck.exceptions.InvalidServerResponseException;
 import com.luca0n.joguitos.pluck.trivia.TriviaQuery;
 import com.luca0n.joguitos.pluck.trivia.TriviaQuestion;
 import com.luca0n.joguitos.pluck.trivia.TriviaQuestionBoolean;
@@ -102,8 +104,15 @@ public class ApiUtil {
 		return GET(query.toString());
 	}
 
-	public static ArrayList<TriviaQuestion> jsonToQuestionArray(String json) throws NoTriviaResultsException {
-		JsonObject jsonObject = new JsonParser().parse(json).getAsJsonObject();
+	public static ArrayList<TriviaQuestion> jsonToQuestionArray(String json)
+			throws NoTriviaResultsException, InvalidServerResponseException {
+		JsonObject jsonObject;
+		try{
+			jsonObject = new JsonParser().parse(json).getAsJsonObject();
+		} catch (JsonSyntaxException e){
+			// Unknown server response.
+			throw new InvalidServerResponseException();
+		}
 
 		if (jsonObject.get("response_code").getAsInt() == 1) {
 			throw new NoTriviaResultsException();

app/src/main/res/values/strings.xml

@@ -83,8 +83,11 @@ Contact us at <joguitos+pluck@luca0n.com>.
     <string name="ui_return_to_menu">Return To Menu</string>
 
     <!-- Error Strings -->
-    <string name="error_network"><b>Network error!</b>\nCould not connect to a network.\n\nIf Tor is enabled in the game settings, check if Orbot is running and then try again.</string>
-    <string name="error_no_trivia_results"><b>No trivia results!</b>\nWas not able to find trivia questions that satisfied all options.</string>
+		<string name="error_network"><b>Network error!</b>\n\nCould not connect to a network. Check if your custom server address is correct. If Tor is enabled in the game settings, check if Orbot is running and then try again.</string>
+		<string name="error_no_trivia_results"><b>No trivia results!</b>\n\nWas not able to find trivia questions that satisfied all options.</string>
+		<string name="error_server_response_invalid"><b>Server response error!</b>\n\nCould not parse the server response. The server response may be in a unsupported version. If you are using a custom server, make sure the server address points to a valid address and then try again.</string>
+		<string name="error_unknown"><b>An unknown error occurred!</b></string>
+
     <string name="title_activity_settings">Settings</string>
 
     <!-- Setting Strings-->
@@ -95,6 +98,6 @@ Contact us at <joguitos+pluck@luca0n.com>.
 		<string name="pref_category_network_title">Network</string>
 		<string name="pref_network_tor_title">Connect Using Tor</string>
 		<string name="pref_network_tor_summary">Retrieves trivia data via the Tor network. Requires Orbot (recommended) or a Tor daemon with a SOCKS5 proxy listening on port 9050.</string>
-		<string name="pref_network_server_title">Server URL</string>
-		<string name="pref_network_server_summary">Specifies the server location used by the game to fetch questions.</string>
+		<string name="pref_network_server_title">Server address</string>
+		<string name="pref_network_server_summary">Specifies the server location used by the game to fetch questions. Leave empty to use the default server.</string>
 </resources>