diff --git a/app/src/main/java/com/termux/api/JobSchedulerAPI.java b/app/src/main/java/com/termux/api/JobSchedulerAPI.java
index 29fa3dd..bfea0c3 100644
--- a/app/src/main/java/com/termux/api/JobSchedulerAPI.java
+++ b/app/src/main/java/com/termux/api/JobSchedulerAPI.java
@@ -12,6 +12,7 @@ import com.termux.api.util.ResultReturner;
 
 import java.io.File;
 import java.io.PrintWriter;
+import java.util.Locale;
 
 public class JobSchedulerAPI {
 
@@ -93,15 +94,13 @@ public class JobSchedulerAPI {
             ResultReturner.returnData(apiReceiver, intent, new ResultReturner.ResultWriter() {
                 @Override
                 public void writeResult(PrintWriter out) {
-                    out.println(String.format("Pending job %d %s", j.getId(), j.toString()));
+                    out.println(String.format(Locale.ENGLISH, "Pending job %d %s", j.getId(), j.toString()));
                 }
             });
         }
 
         ComponentName serviceComponent = new ComponentName(context, SchedulerJobService.class);
-        JobInfo.Builder builder = null;
-        ;
-        builder = new JobInfo.Builder(jobId, serviceComponent)
+        JobInfo.Builder builder = new JobInfo.Builder(jobId, serviceComponent)
                 .setExtras(extras)
                 .setRequiredNetworkType(networkTypeCode)
                 .setRequiresCharging(charging)
@@ -125,7 +124,7 @@ public class JobSchedulerAPI {
         ResultReturner.returnData(apiReceiver, intent, new ResultReturner.ResultWriter() {
             @Override
             public void writeResult(PrintWriter out) {
-                out.println(String.format("Scheduled job %d to call %s every %d ms - response %d",
+                out.println(String.format(Locale.ENGLISH,"Scheduled job %d to call %s every %d ms - response %d",
                         jobId, scriptPath, periodicMillis, scheduleResponse));
             }
         });
diff --git a/app/src/main/java/com/termux/api/MediaPlayerAPI.java b/app/src/main/java/com/termux/api/MediaPlayerAPI.java
index a1abf0f..1f3bf4e 100644
--- a/app/src/main/java/com/termux/api/MediaPlayerAPI.java
+++ b/app/src/main/java/com/termux/api/MediaPlayerAPI.java
@@ -200,7 +200,7 @@ public class MediaPlayerAPI {
             public MediaCommandResult handle(MediaPlayer player, Context context, Intent intent) {
                 MediaCommandResult result = new MediaCommandResult();
 
-                File mediaFile = null;
+                File mediaFile;
                 try {
                     mediaFile = new File(intent.getStringExtra("file"));
                 } catch (NullPointerException e) {
diff --git a/app/src/main/java/com/termux/api/MediaScannerAPI.java b/app/src/main/java/com/termux/api/MediaScannerAPI.java
index 6d76dbb..f0cab62 100644
--- a/app/src/main/java/com/termux/api/MediaScannerAPI.java
+++ b/app/src/main/java/com/termux/api/MediaScannerAPI.java
@@ -54,7 +54,7 @@ public class MediaScannerAPI {
 
     private static void scanFilesRecursively(PrintWriter out, Context context, String[] filePaths, Integer[] totalScanned, Boolean verbose) {
         for (String filePath : filePaths) {
-            Stack subDirs = new Stack();
+            Stack<File> subDirs = new Stack<>();
             File currentPath = new File(filePath);
             while (currentPath != null && currentPath.isDirectory() && currentPath.canRead()) {
                 File[] fileList = null;
diff --git a/app/src/main/java/com/termux/api/ShareAPI.java b/app/src/main/java/com/termux/api/ShareAPI.java
index de11117..4c2d47b 100644
--- a/app/src/main/java/com/termux/api/ShareAPI.java
+++ b/app/src/main/java/com/termux/api/ShareAPI.java
@@ -90,7 +90,7 @@ public class ShareAPI {
                     if (contentTypeExtra == null) {
                         String fileName = fileToShare.getName();
                         int lastDotIndex = fileName.lastIndexOf('.');
-                        String fileExtension = fileName.substring(lastDotIndex + 1, fileName.length());
+                        String fileExtension = fileName.substring(lastDotIndex + 1);
                         MimeTypeMap mimeTypes = MimeTypeMap.getSingleton();
                         // Lower casing makes it work with e.g. "JPG":
                         contentTypeToUse = mimeTypes.getMimeTypeFromExtension(fileExtension.toLowerCase());
diff --git a/app/src/main/java/com/termux/api/TextToSpeechAPI.java b/app/src/main/java/com/termux/api/TextToSpeechAPI.java
index 452eb52..81d21ee 100644
--- a/app/src/main/java/com/termux/api/TextToSpeechAPI.java
+++ b/app/src/main/java/com/termux/api/TextToSpeechAPI.java
@@ -192,7 +192,7 @@ public class TextToSpeechAPI {
     }
 
     private static Locale getLocale(String language, String region, String variant) {
-        Locale result = null;
+        Locale result;
         if (region != null) {
             if (variant != null) {
                 result = new Locale(language, region, variant);