diff --git a/src/androidTest/java/de/dennisguse/opentracks/content/data/TestDataUtil.java b/src/androidTest/java/de/dennisguse/opentracks/content/data/TestDataUtil.java
index 6d828abd0..184790043 100644
--- a/src/androidTest/java/de/dennisguse/opentracks/content/data/TestDataUtil.java
+++ b/src/androidTest/java/de/dennisguse/opentracks/content/data/TestDataUtil.java
@@ -94,11 +94,10 @@ public class TestDataUtil {
      * @return the Waypoint created.
      */
     public static  Waypoint createWaypointWithPhoto(Context context, long trackId, Location location) throws IOException {
-        String photoUrl = "";
         File dstFile = new File(FileUtils.getImageUrl(context, trackId));
         dstFile.createNewFile();
         Uri photoUri = FileUtils.getUriForFile(context, dstFile);
-        photoUrl = photoUri.toString();
+        String photoUrl = photoUri.toString();
 
         return new Waypoint("Waypoint name", "Waypoint description", "Waypoint category", "", trackId, 0.0, 0, location, photoUrl);
     }
diff --git a/src/main/java/de/dennisguse/opentracks/AboutActivity.java b/src/main/java/de/dennisguse/opentracks/AboutActivity.java
index 0d447ed86..72b0e76d3 100644
--- a/src/main/java/de/dennisguse/opentracks/AboutActivity.java
+++ b/src/main/java/de/dennisguse/opentracks/AboutActivity.java
@@ -2,7 +2,6 @@ package de.dennisguse.opentracks;
 
 import android.os.Bundle;
 import android.view.Menu;
-import android.view.ViewGroup;
 import android.widget.TextView;
 
 import androidx.annotation.Nullable;
@@ -30,7 +29,7 @@ public class AboutActivity extends AbstractActivity {
         TextView textURL = findViewById(R.id.about_app_url);
         textURL.setText(getString(R.string.about_url, getString(R.string.app_web_url)));
 
-        ViewUtils.makeClickableLinks((ViewGroup) findViewById(android.R.id.content));
+        ViewUtils.makeClickableLinks(findViewById(android.R.id.content));
     }
 
     protected int getLayoutResId() {
diff --git a/src/main/java/de/dennisguse/opentracks/HelpActivity.java b/src/main/java/de/dennisguse/opentracks/HelpActivity.java
index 59e1d66cc..41152425f 100644
--- a/src/main/java/de/dennisguse/opentracks/HelpActivity.java
+++ b/src/main/java/de/dennisguse/opentracks/HelpActivity.java
@@ -1,7 +1,6 @@
 package de.dennisguse.opentracks;
 
 import android.os.Bundle;
-import android.view.ViewGroup;
 
 import androidx.annotation.Nullable;
 
@@ -12,7 +11,7 @@ public class HelpActivity extends AbstractActivity {
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        ViewUtils.makeClickableLinks((ViewGroup) findViewById(android.R.id.content));
+        ViewUtils.makeClickableLinks(findViewById(android.R.id.content));
     }
 
     @Override
diff --git a/src/main/java/de/dennisguse/opentracks/TrackRecordingActivity.java b/src/main/java/de/dennisguse/opentracks/TrackRecordingActivity.java
index caa0addf7..907cdd268 100644
--- a/src/main/java/de/dennisguse/opentracks/TrackRecordingActivity.java
+++ b/src/main/java/de/dennisguse/opentracks/TrackRecordingActivity.java
@@ -11,7 +11,6 @@ import android.view.MenuItem;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.WindowManager;
-import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
@@ -27,10 +26,8 @@ import de.dennisguse.opentracks.content.provider.ContentProviderUtils;
 import de.dennisguse.opentracks.fragments.ChartFragment;
 import de.dennisguse.opentracks.fragments.ChooseActivityTypeDialogFragment;
 import de.dennisguse.opentracks.fragments.StatisticsRecordingFragment;
-import de.dennisguse.opentracks.services.TrackRecordingServiceCallback;
 import de.dennisguse.opentracks.services.TrackRecordingServiceConnection;
 import de.dennisguse.opentracks.services.TrackRecordingServiceInterface;
-import de.dennisguse.opentracks.services.handlers.GpsStatusValue;
 import de.dennisguse.opentracks.settings.SettingsActivity;
 import de.dennisguse.opentracks.util.IntentDashboardUtils;
 import de.dennisguse.opentracks.util.IntentUtils;
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 aad5c73cd..fbc7e1857 100644
--- a/src/main/java/de/dennisguse/opentracks/content/provider/ContentProviderUtils.java
+++ b/src/main/java/de/dennisguse/opentracks/content/provider/ContentProviderUtils.java
@@ -89,8 +89,8 @@ public class ContentProviderUtils {
      *
      * @param trackId the track id
      */
-    public void clearTrack(Context context, long trackId) {
-        deleteTrackPointsAndWaypoints(context, trackId);
+    public void clearTrack(long trackId) {
+        deleteTrackPointsAndWaypoints(trackId);
         Track track = new Track();
         track.setId(trackId);
         updateTrack(track);
@@ -185,7 +185,7 @@ public class ContentProviderUtils {
      * @param trackId the track id
      */
     public void deleteTrack(Context context, long trackId) {
-        deleteTrackPointsAndWaypoints(context, trackId);
+        deleteTrackPointsAndWaypoints(trackId);
 
         // Delete track folder resources.
         FileUtils.deleteDirectoryRecurse(FileUtils.getPhotoDir(context, trackId));
@@ -199,12 +199,11 @@ public class ContentProviderUtils {
      *
      * @param trackId the track id
      */
-    private void deleteTrackPointsAndWaypoints(Context context, long trackId) {
-        String where = TrackPointsColumns.TRACKID + "=?";
+    private void deleteTrackPointsAndWaypoints(long trackId) {
         String[] selectionArgs = new String[]{Long.toString(trackId)};
-        contentResolver.delete(TrackPointsColumns.CONTENT_URI_BY_ID, where, selectionArgs);
 
-        contentResolver.delete(WaypointsColumns.CONTENT_URI, WaypointsColumns.TRACKID + "=?", new String[]{Long.toString(trackId)});
+        contentResolver.delete(TrackPointsColumns.CONTENT_URI_BY_ID, TrackPointsColumns.TRACKID + "=?", selectionArgs);
+        contentResolver.delete(WaypointsColumns.CONTENT_URI, WaypointsColumns.TRACKID + "=?", selectionArgs);
     }
 
     @VisibleForTesting
diff --git a/src/main/java/de/dennisguse/opentracks/content/provider/ShareContentProvider.java b/src/main/java/de/dennisguse/opentracks/content/provider/ShareContentProvider.java
index 5e8bdb842..2d8da17f1 100644
--- a/src/main/java/de/dennisguse/opentracks/content/provider/ShareContentProvider.java
+++ b/src/main/java/de/dennisguse/opentracks/content/provider/ShareContentProvider.java
@@ -210,7 +210,7 @@ public class ShareContentProvider extends CustomContentProvider implements ICont
 
         final TrackExporter trackExporter = getTrackFileFormat(uri).newTrackExporter(getContext(), tracks);
 
-        PipeDataWriter<String> pipeDataWriter = (PipeDataWriter<String>) (output, uri1, mimeType, opts, args) -> {
+        PipeDataWriter<String> pipeDataWriter = (output, uri1, mimeType, opts, args) -> {
             try (FileOutputStream fileOutputStream = new FileOutputStream(output.getFileDescriptor())) {
                 trackExporter.writeTrack(getContext(), fileOutputStream);
             } catch (IOException e) {
diff --git a/src/main/java/de/dennisguse/opentracks/io/file/importer/AbstractFileTrackImporter.java b/src/main/java/de/dennisguse/opentracks/io/file/importer/AbstractFileTrackImporter.java
index 17415ad85..26630a6d2 100644
--- a/src/main/java/de/dennisguse/opentracks/io/file/importer/AbstractFileTrackImporter.java
+++ b/src/main/java/de/dennisguse/opentracks/io/file/importer/AbstractFileTrackImporter.java
@@ -234,7 +234,7 @@ abstract class AbstractFileTrackImporter extends DefaultHandler implements Track
                 throw new SAXException(createErrorMessage("Cannot import more than one track to an existing track " + importTrackId));
             }
             trackId = importTrackId;
-            contentProviderUtils.clearTrack(context, trackId);
+            contentProviderUtils.clearTrack(trackId);
         }
         trackIds.add(trackId);
         trackData.track.setId(trackId);
diff --git a/src/main/java/de/dennisguse/opentracks/services/handlers/GpsStatus.java b/src/main/java/de/dennisguse/opentracks/services/handlers/GpsStatus.java
index 7ab04d3d0..e682bf803 100644
--- a/src/main/java/de/dennisguse/opentracks/services/handlers/GpsStatus.java
+++ b/src/main/java/de/dennisguse/opentracks/services/handlers/GpsStatus.java
@@ -48,7 +48,7 @@ class GpsStatus {
         }
     }
 
-    private Handler gpsStatusHandler = null;
+    private Handler gpsStatusHandler;
     private GpsStatusRunner gpsStatusRunner = null;
 
     /**
diff --git a/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java b/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java
index bcf0d638b..aa223f592 100644
--- a/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java
+++ b/src/main/java/de/dennisguse/opentracks/util/ActivityUtils.java
@@ -10,7 +10,6 @@ import android.os.Vibrator;
 import android.util.Log;
 import android.util.SparseBooleanArray;
 import android.view.ActionMode;
-import android.view.Gravity;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.AbsListView;
diff --git a/src/main/java/de/dennisguse/opentracks/util/UnitConversions.java b/src/main/java/de/dennisguse/opentracks/util/UnitConversions.java
index 3466fa060..7f878afd8 100644
--- a/src/main/java/de/dennisguse/opentracks/util/UnitConversions.java
+++ b/src/main/java/de/dennisguse/opentracks/util/UnitConversions.java
@@ -66,10 +66,6 @@ public class UnitConversions {
     // multiplication factor to convert meters per second to kilometers per hour
     public static final double MPS_TO_KMH = M_TO_KM / (S_TO_MIN * MIN_TO_HR);
 
-    // Others
-    // multiplication factor to convert degrees to radians
-    public static final double DEG_TO_RAD = Math.PI / 180.0;
-
     private UnitConversions() {
     }
 }