android: Cleanup classes

- Use final modifer wherever possible
- Use try-with-resources for input/output streams

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

app/src/main/java/com/wireguard/android/activity/SettingsActivity.java

@@ -100,7 +100,7 @@ public class SettingsActivity extends AppCompatActivity implements Topic.Subscri
     }
 
     @Override
-    public void onTopicPublished(Topic topic) {
+    public void onTopicPublished(final Topic topic) {
         recreate();
     }
 
@@ -134,7 +134,7 @@ public class SettingsActivity extends AppCompatActivity implements Topic.Subscri
         }
 
         @Override
-        public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+        public void onSharedPreferenceChanged(final SharedPreferences sharedPreferences, final String key) {
             if ("dark_theme".equals(key)) {
                 AppCompatDelegate.setDefaultNightMode(
                         sharedPreferences.getBoolean(key, false) ? AppCompatDelegate.MODE_NIGHT_YES : AppCompatDelegate.MODE_NIGHT_NO);

app/src/main/java/com/wireguard/android/backend/GoBackend.java

@@ -137,7 +137,7 @@ public final class GoBackend implements Backend {
             // Build config
             final Interface iface = config.getInterface();
             final String goConfig;
-            try (Formatter fmt = new Formatter(new StringBuilder())) {
+            try (final Formatter fmt = new Formatter(new StringBuilder())) {
                 fmt.format("replace_peers=true\n");
                 if (iface.getPrivateKey() != null)
                     fmt.format("private_key=%s\n", KeyEncoding.keyToHex(KeyEncoding.keyFromBase64(iface.getPrivateKey())));
@@ -184,11 +184,12 @@ public final class GoBackend implements Backend {
             builder.setMtu(mtu);
 
             builder.setBlocking(true);
-            final ParcelFileDescriptor tun = builder.establish();
+            try (final ParcelFileDescriptor tun = builder.establish()) {
                 if (tun == null)
                     throw new Exception("Unable to create tun device");
 
                 currentTunnelHandle = wgTurnOn(tunnel.getName(), tun.detachFd(), goConfig);
+            }
             if (currentTunnelHandle < 0)
                 throw new Exception("Unable to turn tunnel on (wgTurnOn return " + currentTunnelHandle + ')');
 
@@ -237,7 +238,7 @@ public final class GoBackend implements Backend {
         }
 
         @Override
-        public int onStartCommand(Intent intent, int flags, int startId) {
+        public int onStartCommand(final Intent intent, final int flags, final int startId) {
             vpnService.complete(this);
             if (intent == null || intent.getComponent() == null || !intent.getComponent().getPackageName().equals(getPackageName())) {
                 Log.d(TAG, "Service started by Always-on VPN feature");

app/src/main/java/com/wireguard/android/backend/WgQuickBackend.java

@@ -106,7 +106,7 @@ public final class WgQuickBackend implements Backend {
     private void setStateInternal(final Tunnel tunnel, final Config config, final State state)
             throws Exception {
         final File tempFile = new File(localTemporaryDir, tunnel.getName() + ".conf");
-        try (FileOutputStream stream = new FileOutputStream(tempFile, false)) {
+        try (final FileOutputStream stream = new FileOutputStream(tempFile, false)) {
             stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
         }
         final String command = String.format("wg-quick %s '%s'",

app/src/main/java/com/wireguard/android/configStore/FileConfigStore.java

@@ -42,7 +42,7 @@ public final class FileConfigStore implements ConfigStore {
         final File file = fileFor(name);
         if (!file.createNewFile())
             throw new IOException("Configuration file " + file.getName() + " already exists");
-        try (FileOutputStream stream = new FileOutputStream(file, false)) {
+        try (final FileOutputStream stream = new FileOutputStream(file, false)) {
             stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
         }
         return config;
@@ -70,7 +70,7 @@ public final class FileConfigStore implements ConfigStore {
 
     @Override
     public Config load(final String name) throws IOException {
-        try (FileInputStream stream = new FileInputStream(fileFor(name))) {
+        try (final FileInputStream stream = new FileInputStream(fileFor(name))) {
             return Config.from(stream);
         }
     }
@@ -95,7 +95,7 @@ public final class FileConfigStore implements ConfigStore {
         final File file = fileFor(name);
         if (!file.isFile())
             throw new FileNotFoundException("Configuration file " + file.getName() + " not found");
-        try (FileOutputStream stream = new FileOutputStream(file, false)) {
+        try (final FileOutputStream stream = new FileOutputStream(file, false)) {
             stream.write(config.toString().getBytes(StandardCharsets.UTF_8));
         }
         return config;

app/src/main/java/com/wireguard/android/model/TunnelManager.java

@@ -57,7 +57,7 @@ public final class TunnelManager extends BaseObservable {
             new ObservableSortedKeyedArrayList<>(COMPARATOR);
     private Tunnel lastUsedTunnel;
     private boolean haveLoaded;
-    private ArrayList<CompletableFuture<Void>> delayedLoadRestoreTunnels = new ArrayList<>();
+    private final ArrayList<CompletableFuture<Void>> delayedLoadRestoreTunnels = new ArrayList<>();
 
     @Inject
     public TunnelManager(final AsyncWorker asyncWorker, final Backend backend,
@@ -150,7 +150,7 @@ public final class TunnelManager extends BaseObservable {
         final String lastUsedName = preferences.getString(KEY_LAST_USED_TUNNEL, null);
         if (lastUsedName != null)
             setLastUsedTunnel(tunnels.get(lastUsedName));
-        CompletableFuture<Void> toComplete[];
+        final CompletableFuture<Void>[] toComplete;
         synchronized (delayedLoadRestoreTunnels) {
             haveLoaded = true;
             toComplete = delayedLoadRestoreTunnels.toArray(new CompletableFuture[delayedLoadRestoreTunnels.size()]);
@@ -175,12 +175,12 @@ public final class TunnelManager extends BaseObservable {
                 .whenComplete(ExceptionLoggers.E);
     }
 
-    public CompletionStage<Void> restoreState(boolean force) {
+    public CompletionStage<Void> restoreState(final boolean force) {
         if (!force && !preferences.getBoolean(KEY_RESTORE_ON_BOOT, false))
             return CompletableFuture.completedFuture(null);
         synchronized (delayedLoadRestoreTunnels) {
             if (!haveLoaded) {
-                CompletableFuture<Void> f = new CompletableFuture<>();
+                final CompletableFuture<Void> f = new CompletableFuture<>();
                 delayedLoadRestoreTunnels.add(f);
                 return f;
             }

app/src/main/java/com/wireguard/android/preference/LogExporterPreference.java

@@ -75,7 +75,8 @@ public class LogExporterPreference extends Preference {
                         throw new Exception(errors.toString());
                     }
                 }
-            } catch (Exception e) {
+            } catch (final Exception e) {
+                // noinspection ResultOfMethodCallIgnored
                 file.delete();
                 throw e;
             }

app/src/main/java/com/wireguard/android/preference/VersionPreference.java

@@ -27,10 +27,9 @@ public class VersionPreference extends Preference {
             versionSummary = getContext().getString(R.string.version_userspace_summary, GoBackend.getVersion());
         } else if (Application.getComponent().getBackendType() == WgQuickBackend.class) {
             Application.getComponent().getToolsInstaller().getVersion().whenComplete((version, exception) -> {
-                if (exception == null)
+                versionSummary = exception == null
-                    versionSummary = getContext().getString(R.string.version_kernel_summary, version);
+                        ? getContext().getString(R.string.version_kernel_summary, version)
-                else
+                        : getContext().getString(R.string.version_kernel_unknown_summary);
-                    versionSummary = getContext().getString(R.string.version_kernel_unknown_summary);
                 notifyChanged();
             });
         }

app/src/main/java/com/wireguard/android/preference/ZipExporterPreference.java

@@ -81,8 +81,7 @@ public class ZipExporterPreference extends Preference {
                                     toString().getBytes(StandardCharsets.UTF_8));
                         }
                         zip.closeEntry();
-                        zip.close();
+                    } catch (final Exception e) {
-                    } catch (Exception e) {
                         // noinspection ResultOfMethodCallIgnored
                         file.delete();
                         throw e;

app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java

@@ -22,7 +22,7 @@ public final class SharedLibraryLoader {
     private SharedLibraryLoader() {
     }
 
-    public static final void loadSharedLibrary(final Context context, final String libName) {
+    public static void loadSharedLibrary(final Context context, final String libName) {
         Throwable noAbiException;
         try {
             System.loadLibrary(libName);
@@ -35,12 +35,12 @@ public final class SharedLibraryLoader {
         final ZipFile zipFile;
         try {
             zipFile = new ZipFile(new File(context.getApplicationInfo().sourceDir), ZipFile.OPEN_READ);
-        } catch (IOException e) {
+        } catch (final IOException e) {
             throw new RuntimeException(e);
         }
 
         final String mappedLibName = System.mapLibraryName(libName);
-        byte buffer[] = new byte[1024 * 32];
+        final byte[] buffer = new byte[1024 * 32];
         for (final String abi : Build.SUPPORTED_ABIS) {
             final String libZipPath = "lib" + File.separatorChar + abi + File.separatorChar + mappedLibName;
             final ZipEntry zipEntry = zipFile.getEntry(libZipPath);
@@ -50,13 +50,13 @@ public final class SharedLibraryLoader {
             try {
                 f = File.createTempFile("lib", ".so", context.getCacheDir());
                 Log.d(TAG, "Extracting apk:/" + libZipPath + " to " + f.getAbsolutePath() + " and loading");
-                FileOutputStream out = new FileOutputStream(f);
+                try (final FileOutputStream out = new FileOutputStream(f);
-                InputStream in = zipFile.getInputStream(zipEntry);
+                     final InputStream in = zipFile.getInputStream(zipEntry)) {
                     int len;
                     while ((len = in.read(buffer)) != -1) {
                         out.write(buffer, 0, len);
                     }
-                out.close();
+                }
                 System.load(f.getAbsolutePath());
                 return;
             } catch (Exception e) {
@@ -64,6 +64,7 @@ public final class SharedLibraryLoader {
                 noAbiException = e;
             } finally {
                 if (f != null)
+                    // noinspection ResultOfMethodCallIgnored
                     f.delete();
             }
         }

app/src/main/java/com/wireguard/android/util/ToolsInstaller.java

@@ -58,7 +58,7 @@ public final class ToolsInstaller {
 
     public CompletionStage<String> getVersion() {
         return Application.getComponent().getAsyncWorker().supplyAsync(() -> {
-            final ArrayList<String> output = new ArrayList<>();
+            final List<String> output = new ArrayList<>();
             if (rootShell.run(output, "cat /sys/module/wireguard/version") != 0 || output.isEmpty())
                 throw new RuntimeException("Unable to determine kernel module version");
             return output.get(0);

app/src/main/java/com/wireguard/android/util/Topic.java

@@ -28,7 +28,7 @@ public class Topic {
         subscribers = new SyncArrayList<>();
     }
 
-    public synchronized void subscribe(Subscriber sub) {
+    public synchronized void subscribe(final Subscriber sub) {
         subscribers.add(new WeakReference<>(sub));
     }
 
@@ -36,10 +36,10 @@ public class Topic {
         subscribers = new SyncArrayList<>();
     }
 
-    public synchronized void unsubscribe(Subscriber sub) {
+    public synchronized void unsubscribe(final Subscriber sub) {
         List<WeakReference<Subscriber>> subs = subscribers;
         subscribers = new ArrayList<>();
-        for (WeakReference<Subscriber> subscriber : subs) {
+        for (final WeakReference<Subscriber> subscriber : subs) {
             if (subscriber.get() != null && subscriber.get() != sub)
                 subscribers.add(subscriber);
         }
@@ -64,7 +64,7 @@ public class Topic {
         this.results = results;
         // Snapshot
         List<WeakReference<Subscriber>> subs = subscribers;
-        for (WeakReference<Subscriber> subscriber : subs) {
+        for (final WeakReference<Subscriber> subscriber : subs) {
             if (subscriber != null && subscriber.get() != null)
                 subscriber.get().onTopicPublished(this);
         }
@@ -84,7 +84,7 @@ public class Topic {
 
     public interface Subscriber {
         default void subscribeTopics() {
-            for (Topic topic : getSubscription()) {
+            for (final Topic topic : getSubscription()) {
                 if (topic.isPublished()) {
                     onTopicPublished(topic);
                 }
@@ -92,7 +92,7 @@ public class Topic {
             }
         }
         default void unsubscribeTopics() {
-            for (Topic event : getSubscription()) {
+            for (final Topic event : getSubscription()) {
                 event.unsubscribe(this);
             }
         }
@@ -102,7 +102,7 @@ public class Topic {
 
     private static class SyncArrayList<E> extends ArrayList<E> {
         @Override
-        public synchronized boolean add(E e) {
+        public synchronized boolean add(final E e) {
             return super.add(e);
         }
     }