diff --git a/src/androidTest/java/de/dennisguse/opentracks/EspressoDeleteTrackTest.java b/src/androidTest/java/de/dennisguse/opentracks/EspressoDeleteTrackTest.java
index 8a98e3f57..bbdd6bc80 100644
--- a/src/androidTest/java/de/dennisguse/opentracks/EspressoDeleteTrackTest.java
+++ b/src/androidTest/java/de/dennisguse/opentracks/EspressoDeleteTrackTest.java
@@ -239,7 +239,7 @@ public class EspressoDeleteTrackTest {
     }
 
 
-    private class MyIdlingResource implements IdlingResource {
+    private static class MyIdlingResource implements IdlingResource {
 
         private final Context context;
         private ResourceCallback resourceCallback;
diff --git a/src/main/java/de/dennisguse/opentracks/AbstractTrackDeleteActivity.java b/src/main/java/de/dennisguse/opentracks/AbstractTrackDeleteActivity.java
index b86f42617..bd0317ed5 100644
--- a/src/main/java/de/dennisguse/opentracks/AbstractTrackDeleteActivity.java
+++ b/src/main/java/de/dennisguse/opentracks/AbstractTrackDeleteActivity.java
@@ -120,6 +120,6 @@ public abstract class AbstractTrackDeleteActivity extends AbstractActivity imple
         if (service == null) {
             return;
         }
-        service.getDeletingStatusObservable().observe(AbstractTrackDeleteActivity.this, status -> onTrackDeleteStatus(status));
+        service.getDeletingStatusObservable().observe(AbstractTrackDeleteActivity.this, this::onTrackDeleteStatus);
     }
 }
diff --git a/src/main/java/de/dennisguse/opentracks/TrackListActivity.java b/src/main/java/de/dennisguse/opentracks/TrackListActivity.java
index 83bdee7b3..a3b831939 100644
--- a/src/main/java/de/dennisguse/opentracks/TrackListActivity.java
+++ b/src/main/java/de/dennisguse/opentracks/TrackListActivity.java
@@ -109,18 +109,15 @@ public class TrackListActivity extends AbstractTrackDeleteActivity implements Co
         }
     };
 
-    private final OnSharedPreferenceChangeListener sharedPreferenceChangeListener = new OnSharedPreferenceChangeListener() {
-        @Override
-        public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
-            if (PreferencesUtils.isKey(TrackListActivity.this, R.string.stats_units_key, key)) {
-                metricUnits = PreferencesUtils.isMetricUnits(sharedPreferences, TrackListActivity.this);
-            }
-            if (key != null) {
-                runOnUiThread(() -> {
-                    TrackListActivity.this.invalidateOptionsMenu();
-                    loaderCallbacks.restart();
-                });
-            }
+    private final OnSharedPreferenceChangeListener sharedPreferenceChangeListener = (sharedPreferences, key) -> {
+        if (PreferencesUtils.isKey(TrackListActivity.this, R.string.stats_units_key, key)) {
+            metricUnits = PreferencesUtils.isMetricUnits(sharedPreferences, TrackListActivity.this);
+        }
+        if (key != null) {
+            runOnUiThread(() -> {
+                TrackListActivity.this.invalidateOptionsMenu();
+                loaderCallbacks.restart();
+            });
         }
     };
 
diff --git a/src/main/java/de/dennisguse/opentracks/adapters/IntervalStatisticsAdapter.java b/src/main/java/de/dennisguse/opentracks/adapters/IntervalStatisticsAdapter.java
index fed2e69e2..2af5a2822 100644
--- a/src/main/java/de/dennisguse/opentracks/adapters/IntervalStatisticsAdapter.java
+++ b/src/main/java/de/dennisguse/opentracks/adapters/IntervalStatisticsAdapter.java
@@ -92,10 +92,10 @@ public class IntervalStatisticsAdapter extends RecyclerView.Adapter<RecyclerView
     }
 
     private static class ViewHolder extends RecyclerView.ViewHolder {
-        TextView distance;
-        TextView rate;
-        TextView gain;
-        TextView loss;
+        final TextView distance;
+        final TextView rate;
+        final TextView gain;
+        final TextView loss;
 
         public ViewHolder(@NonNull View itemView) {
             super(itemView);
diff --git a/src/main/java/de/dennisguse/opentracks/content/provider/ContentProviderUtils.java b/src/main/java/de/dennisguse/opentracks/content/provider/ContentProviderUtils.java
index 605dbecd3..0b6e85578 100644
--- a/src/main/java/de/dennisguse/opentracks/content/provider/ContentProviderUtils.java
+++ b/src/main/java/de/dennisguse/opentracks/content/provider/ContentProviderUtils.java
@@ -37,7 +37,6 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.UUID;
-import java.util.stream.StreamSupport;
 
 import de.dennisguse.opentracks.BuildConfig;
 import de.dennisguse.opentracks.content.data.Altitude;
diff --git a/src/main/java/de/dennisguse/opentracks/io/file/importer/GpxTrackImporter.java b/src/main/java/de/dennisguse/opentracks/io/file/importer/GpxTrackImporter.java
index 3f3b8f629..771fe4da8 100644
--- a/src/main/java/de/dennisguse/opentracks/io/file/importer/GpxTrackImporter.java
+++ b/src/main/java/de/dennisguse/opentracks/io/file/importer/GpxTrackImporter.java
@@ -130,7 +130,7 @@ public class GpxTrackImporter extends DefaultHandler implements XMLImporter.Trac
                 trackImporter.newTrack();
                 break;
             case TAG_TRACK_SEGMENT:
-                onTrackSegmentStart();
+                //Nothing to do here.
                 break;
             case TAG_TRACK_POINT:
                 onTrackPointStart(attributes);
@@ -236,9 +236,6 @@ public class GpxTrackImporter extends DefaultHandler implements XMLImporter.Trac
         content = "";
     }
 
-    private void onTrackSegmentStart() {
-    }
-
     private void onTrackSegmentEnd() {
         if (currentSegment.isEmpty()) {
             Log.w(TAG, "No locations in current segment.");
diff --git a/src/main/java/de/dennisguse/opentracks/io/file/importer/ParsingException.java b/src/main/java/de/dennisguse/opentracks/io/file/importer/ParsingException.java
index b679f2d55..0c3255c02 100644
--- a/src/main/java/de/dennisguse/opentracks/io/file/importer/ParsingException.java
+++ b/src/main/java/de/dennisguse/opentracks/io/file/importer/ParsingException.java
@@ -4,10 +4,6 @@ import androidx.annotation.NonNull;
 
 public class ParsingException extends RuntimeException {
 
-    private ParsingException(@NonNull String message) {
-        super(message);
-    }
-
     protected ParsingException(@NonNull String message, Exception cause) {
         super(message, cause);
     }
diff --git a/src/main/java/de/dennisguse/opentracks/io/file/importer/TrackImporter.java b/src/main/java/de/dennisguse/opentracks/io/file/importer/TrackImporter.java
index 88a0527a5..11bba0f7d 100644
--- a/src/main/java/de/dennisguse/opentracks/io/file/importer/TrackImporter.java
+++ b/src/main/java/de/dennisguse/opentracks/io/file/importer/TrackImporter.java
@@ -12,7 +12,6 @@ import java.time.Duration;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.Comparator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
@@ -140,17 +139,14 @@ public class TrackImporter {
             track.setUuid(UUID.randomUUID());
         }
 
-        Collections.sort(trackPoints, new Comparator<TrackPoint>() {
-            @Override
-            public int compare(TrackPoint o1, TrackPoint o2) {
-                if (o1.getTime().isBefore(o2.getTime())) {
-                    return -1;
-                }
-                if (o1.getTime().isAfter(o2.getTime())) {
-                    return 1;
-                }
-                return 0;
+        Collections.sort(trackPoints, (o1, o2) -> {
+            if (o1.getTime().isBefore(o2.getTime())) {
+                return -1;
             }
+            if (o1.getTime().isAfter(o2.getTime())) {
+                return 1;
+            }
+            return 0;
         });
 
         TrackStatisticsUpdater updater = new TrackStatisticsUpdater();
diff --git a/src/main/java/de/dennisguse/opentracks/services/TrackDeleteService.java b/src/main/java/de/dennisguse/opentracks/services/TrackDeleteService.java
index f8f60bcca..c97259a93 100644
--- a/src/main/java/de/dennisguse/opentracks/services/TrackDeleteService.java
+++ b/src/main/java/de/dennisguse/opentracks/services/TrackDeleteService.java
@@ -137,9 +137,9 @@ public class TrackDeleteService extends Service {
     }
 
     public static class DeleteStatus {
-        private int progress;
-        private int max;
-        private Track.Id trackId;
+        private final int progress;
+        private final int max;
+        private final Track.Id trackId;
 
         /**
          * @param trackId  Track.Id just deleted if any.
diff --git a/src/main/java/de/dennisguse/opentracks/services/TrackRecordingService.java b/src/main/java/de/dennisguse/opentracks/services/TrackRecordingService.java
index 979efec5b..df1089bc2 100644
--- a/src/main/java/de/dennisguse/opentracks/services/TrackRecordingService.java
+++ b/src/main/java/de/dennisguse/opentracks/services/TrackRecordingService.java
@@ -240,20 +240,6 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
         return trackStatisticsUpdater.getTrackStatistics();
     }
 
-    //TODO Throw exception, when not recording.
-    public Duration getTotalTime() {
-        if (trackStatisticsUpdater == null) {
-            return Duration.ofSeconds(0);
-        }
-        if (isPaused()) {
-            return trackStatisticsUpdater.getTrackStatistics().getTotalTime();
-        }
-
-        TrackStatistics statistics = trackStatisticsUpdater.getTrackStatistics();
-        return Duration.between(statistics.getStopTime(), Instant.now())
-                .plus(statistics.getTotalTime());
-    }
-
     public Marker.Id insertMarker(String name, String category, String description, String photoUrl) {
         if (!isRecording() || isPaused()) {
             return null;
diff --git a/src/main/java/de/dennisguse/opentracks/services/sensors/AltitudeSumManager.java b/src/main/java/de/dennisguse/opentracks/services/sensors/AltitudeSumManager.java
index fbd46af69..91e04ef5f 100644
--- a/src/main/java/de/dennisguse/opentracks/services/sensors/AltitudeSumManager.java
+++ b/src/main/java/de/dennisguse/opentracks/services/sensors/AltitudeSumManager.java
@@ -10,8 +10,6 @@ import android.util.Log;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 
-import java.time.Duration;
-
 import de.dennisguse.opentracks.util.PressureSensorUtils;
 
 /**
@@ -21,8 +19,6 @@ public class AltitudeSumManager implements SensorEventListener {
 
     private static final String TAG = AltitudeSumManager.class.getSimpleName();
 
-    private static final Duration SAMPLING_RATE = Duration.ofSeconds(3);
-
     private boolean isConnected = false;
 
     private float lastAcceptedPressureValue_hPa;
diff --git a/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java b/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java
index c3e375d3d..97b47fbdf 100644
--- a/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java
+++ b/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java
@@ -14,7 +14,6 @@ import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.AbsListView;
 import android.widget.ListView;
-import android.widget.Toast;
 
 import androidx.appcompat.app.AppCompatDelegate;
 import androidx.appcompat.widget.SearchView;
@@ -109,12 +108,6 @@ public class ActivityUtils {
         }
     }
 
-    public static void toast(final Activity activity, final int resId, final int duration, final int gravity) {
-        final Toast toast = Toast.makeText(activity, resId, duration);
-        toast.setGravity(gravity, 0, 0);
-        toast.show();
-    }
-
     public static void applyNightMode(SharedPreferences sharedPreferences, Context context) {
         AppCompatDelegate.setDefaultNightMode(PreferencesUtils.getDefaultNightMode(sharedPreferences, context));
     }