some requested fixes

app/src/main/java/org/traccar/client/MainActivity.java

@@ -39,8 +39,6 @@ import android.view.MenuItem;
 import android.webkit.URLUtil;
 import android.widget.Toast;
 
-import java.net.MalformedURLException;
-import java.net.URL;
 import java.util.HashSet;
 import java.util.Random;
 import java.util.Set;
@@ -73,7 +71,7 @@ public class MainActivity extends PreferenceActivity implements OnSharedPreferen
         }
 
         sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
-        migratePreferencesIfNecessary(sharedPreferences);
+        migrateLegacyPreferences(sharedPreferences);
         addPreferencesFromResource(R.xml.preferences);
         initPreferences();
 
@@ -304,17 +302,17 @@ public class MainActivity extends PreferenceActivity implements OnSharedPreferen
             preference.setSummary(R.string.settings_url_summary);
             findPreference(KEY_STATUS).setEnabled(true);
         } else {
-            preference.setSummary(R.string.settings_invalid_url_summary);
+            preference.setSummary(R.string.error_invalid_url_summary);
             findPreference(KEY_STATUS).setEnabled(false);
-            Toast.makeText(MainActivity.this, R.string.msg_invalid_url, Toast.LENGTH_LONG).show();
+            Toast.makeText(MainActivity.this, R.string.error_msg_invalid_url, Toast.LENGTH_LONG).show();
         }
         return true;
     }
 
-    private void migratePreferencesIfNecessary(SharedPreferences preferences) {
+    private void migrateLegacyPreferences(SharedPreferences preferences) {
         String port = preferences.getString("port", null);
         if (port != null) {
-            Log.d(TAG, "migratePreferencesIfNecessary: migrating to URL preference");
+            Log.d(TAG, "migrateLegacyPreferences: migrating to URL preference");
 
             String host = preferences.getString("address", getString(R.string.settings_url_default_value));
             String scheme = preferences.getBoolean("secure", false) ? "https" : "http";
@@ -327,11 +325,7 @@ public class MainActivity extends PreferenceActivity implements OnSharedPreferen
             editor.remove("port");
             editor.remove("address");
             editor.remove("secure");
-            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.GINGERBREAD) {
-                editor.commit();
-            } else {
-                editor.apply();
-            }
+            editor.commit();
         }
     }
 }

app/src/main/java/org/traccar/client/ProtocolFormatter.java

@@ -24,7 +24,8 @@ public class ProtocolFormatter {
     }
 
     public static String formatRequest(String url, Position position, String alarm) {
-        Uri serverUrl = Uri.parse(url).buildUpon()
+        Uri serverUrl = Uri.parse(url);
+        Uri.Builder builder = serverUrl.buildUpon()
                 .appendQueryParameter("id", position.getDeviceId())
                 .appendQueryParameter("timestamp", String.valueOf(position.getTime().getTime() / 1000))
                 .appendQueryParameter("lat", String.valueOf(position.getLatitude()))
@@ -32,19 +33,16 @@ public class ProtocolFormatter {
                 .appendQueryParameter("speed", String.valueOf(position.getSpeed()))
                 .appendQueryParameter("bearing", String.valueOf(position.getCourse()))
                 .appendQueryParameter("altitude", String.valueOf(position.getAltitude()))
-                .appendQueryParameter("batt", String.valueOf(position.getBattery()))
-                .build();
+                .appendQueryParameter("batt", String.valueOf(position.getBattery()));
 
-        if (alarm != null && alarm.trim().length() != 0) {
-            serverUrl = serverUrl.buildUpon().appendQueryParameter("alarm", alarm).build();
+        if (alarm != null) {
+            builder.appendQueryParameter("alarm", alarm);
         }
+
         int port = serverUrl.getPort();
         if (port < 0 || port > 65535) {
-            port = 5055;
-            String host = serverUrl.getHost();
-            serverUrl = serverUrl.buildUpon().encodedAuthority(host + ":" + port).build();
+            builder.encodedAuthority(serverUrl.getHost() + ":" + 5055);
         }
-        return serverUrl.toString();
+        return builder.build().toString();
     }
-
 }