diff --git a/src/org/kde/kdeconnect/Plugins/MprisReceiverPlugin/MprisReceiverPlugin.java b/src/org/kde/kdeconnect/Plugins/MprisReceiverPlugin/MprisReceiverPlugin.java
index 9dfc9b70..04e74757 100644
--- a/src/org/kde/kdeconnect/Plugins/MprisReceiverPlugin/MprisReceiverPlugin.java
+++ b/src/org/kde/kdeconnect/Plugins/MprisReceiverPlugin/MprisReceiverPlugin.java
@@ -213,18 +213,12 @@ public class MprisReceiverPlugin extends Plugin implements MediaSessionManager.O
         return new AlertDialog.Builder(deviceActivity)
                 .setTitle(R.string.pref_plugin_mpris)
                 .setMessage(R.string.no_permission_mprisreceiver)
-                .setPositiveButton(R.string.open_settings, new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialogInterface, int i) {
-                        Intent intent = new Intent("android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS");
-                        deviceActivity.startActivityForResult(intent, MainActivity.RESULT_NEEDS_RELOAD);
-                    }
+                .setPositiveButton(R.string.open_settings, (dialogInterface, i) -> {
+                    Intent intent = new Intent("android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS");
+                    deviceActivity.startActivityForResult(intent, MainActivity.RESULT_NEEDS_RELOAD);
                 })
-                .setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialogInterface, int i) {
-                        //Do nothing
-                    }
+                .setNegativeButton(R.string.cancel, (dialogInterface, i) -> {
+                    //Do nothing
                 })
                 .create();
     }
diff --git a/src/org/kde/kdeconnect/Plugins/PresenterPlugin/PresenterActivity.java b/src/org/kde/kdeconnect/Plugins/PresenterPlugin/PresenterActivity.java
index 1fd0ec23..bbfeecb7 100644
--- a/src/org/kde/kdeconnect/Plugins/PresenterPlugin/PresenterActivity.java
+++ b/src/org/kde/kdeconnect/Plugins/PresenterPlugin/PresenterActivity.java
@@ -64,13 +64,9 @@ public class PresenterActivity extends AppCompatActivity {
 
             runOnUiThread(() -> {
 
-                findViewById(R.id.next_button).setOnClickListener(v -> {
-                    plugin.sendNext();
-                });
+                findViewById(R.id.next_button).setOnClickListener(v -> plugin.sendNext());
 
-                findViewById(R.id.previous_button).setOnClickListener(v -> {
-                    plugin.sendPrevious();
-                });
+                findViewById(R.id.previous_button).setOnClickListener(v -> plugin.sendPrevious());
 
 
             });
diff --git a/src/org/kde/kdeconnect/Plugins/SystemvolumePlugin/SystemvolumeFragment.java b/src/org/kde/kdeconnect/Plugins/SystemvolumePlugin/SystemvolumeFragment.java
index ffde3fe6..15324db7 100644
--- a/src/org/kde/kdeconnect/Plugins/SystemvolumePlugin/SystemvolumeFragment.java
+++ b/src/org/kde/kdeconnect/Plugins/SystemvolumePlugin/SystemvolumeFragment.java
@@ -59,36 +59,28 @@ public class SystemvolumeFragment extends ListFragment implements Sink.UpdateLis
         // Don't set progress while the slider is moved
         if (!tracking) {
 
-            activity.runOnUiThread(new Runnable() {
-                @Override
-                public void run() {
-                    adapter.notifyDataSetChanged();
-                }
-            });
+            activity.runOnUiThread(() -> adapter.notifyDataSetChanged());
         }
     }
 
     public void connectToPlugin(final String deviceId) {
 
-        BackgroundService.RunCommand(activity, new BackgroundService.InstanceCallback() {
-            @Override
-            public void onServiceStart(BackgroundService service) {
-                Device device = service.getDevice(deviceId);
+        BackgroundService.RunCommand(activity, service -> {
+            Device device = service.getDevice(deviceId);
 
-                if (device == null)
-                    return;
+            if (device == null)
+                return;
 
-                plugin = device.getPlugin(SystemvolumePlugin.class);
+            plugin = device.getPlugin(SystemvolumePlugin.class);
 
-                if (plugin == null) {
-                    Log.e("SystemvolumeFragment", "device has no systemvolume plugin!");
-                    return;
-                }
-
-                plugin.addSinkListener(SystemvolumeFragment.this);
-                plugin.requestSinkList();
-                Log.d("Systemvolume", "requestSinklist");
+            if (plugin == null) {
+                Log.e("SystemvolumeFragment", "device has no systemvolume plugin!");
+                return;
             }
+
+            plugin.addSinkListener(SystemvolumeFragment.this);
+            plugin.requestSinkList();
+            Log.d("Systemvolume", "requestSinklist");
         });
 
     }
@@ -107,12 +99,9 @@ public class SystemvolumeFragment extends ListFragment implements Sink.UpdateLis
             sink.addListener(SystemvolumeFragment.this);
         }
 
-        activity.runOnUiThread(new Runnable() {
-            @Override
-            public void run() {
-                adapter = new SinkAdapter(context, plugin.getSinks().toArray(new Sink[0]));
-                setListAdapter(adapter);
-            }
+        activity.runOnUiThread(() -> {
+            adapter = new SinkAdapter(context, plugin.getSinks().toArray(new Sink[0]));
+            setListAdapter(adapter);
         });
     }
 
@@ -157,12 +146,7 @@ public class SystemvolumeFragment extends ListFragment implements Sink.UpdateLis
 
         @Override
         public void onProgressChanged(final SeekBar seekBar, int i, boolean b) {
-            BackgroundService.RunCommand(activity, new BackgroundService.InstanceCallback() {
-                @Override
-                public void onServiceStart(BackgroundService service) {
-                    plugin.sendVolume(sink.getName(), seekBar.getProgress());
-                }
-            });
+            BackgroundService.RunCommand(activity, service -> plugin.sendVolume(sink.getName(), seekBar.getProgress()));
         }
 
         @Override
@@ -173,12 +157,7 @@ public class SystemvolumeFragment extends ListFragment implements Sink.UpdateLis
         @Override
         public void onStopTrackingTouch(final SeekBar seekBar) {
             tracking = false;
-            BackgroundService.RunCommand(activity, new BackgroundService.InstanceCallback() {
-                @Override
-                public void onServiceStart(BackgroundService service) {
-                    plugin.sendVolume(sink.getName(), seekBar.getProgress());
-                }
-            });
+            BackgroundService.RunCommand(activity, service -> plugin.sendVolume(sink.getName(), seekBar.getProgress()));
         }
 
         @Override
diff --git a/src/org/kde/kdeconnect/UserInterface/MainActivity.java b/src/org/kde/kdeconnect/UserInterface/MainActivity.java
index 540cf248..f5a56740 100644
--- a/src/org/kde/kdeconnect/UserInterface/MainActivity.java
+++ b/src/org/kde/kdeconnect/UserInterface/MainActivity.java
@@ -154,16 +154,12 @@ public class MainActivity extends AppCompatActivity {
 
         SwitchCompat darkThemeSwitch = (SwitchCompat) drawerHeader.findViewById(R.id.dark_theme);
         darkThemeSwitch.setChecked(ThemeUtil.shouldUseDarkTheme(this));
-        darkThemeSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
-            @RequiresApi(Build.VERSION_CODES.HONEYCOMB)
-            @Override
-            public void onCheckedChanged(CompoundButton darkThemeSwitch, boolean isChecked) {
-                SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(MainActivity.this);
-                boolean isDarkAlready = prefs.getBoolean("darkTheme", false);
-                if (isDarkAlready != isChecked) {
-                    prefs.edit().putBoolean("darkTheme", isChecked).apply();
-                    MainActivity.this.recreate();
-                }
+        darkThemeSwitch.setOnCheckedChangeListener((darkThemeSwitch1, isChecked) -> {
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(MainActivity.this);
+            boolean isDarkAlready = prefs.getBoolean("darkTheme", false);
+            if (isDarkAlready != isChecked) {
+                prefs.edit().putBoolean("darkTheme", isChecked).apply();
+                MainActivity.this.recreate();
             }
         });
     }