Use try-with-resources

app/build.gradle

@@ -48,6 +48,12 @@ android {
         }
     }
 
+    compileOptions {
+        encoding "UTF-8"
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
+    }
+
     lint {
         disable 'MissingTranslation'
         lintConfig file('lint.xml')
@@ -129,6 +135,7 @@ dependencies {
     implementation 'org.jcodec:jcodec:0.2.3'
     implementation 'com.squareup.okhttp3:okhttp:3.12.13'
     implementation 'com.squareup.okio:okio:1.17.5'
+    // 3.5.8 requires minSdk 19, uses StandardCharsets.UTF_8 internally
     implementation 'org.jmdns:jmdns:3.5.7'
     implementation 'com.github.cgutman:ShieldControllerExtensions:1.0'
 }

app/src/main/java/com/limelight/binding/crypto/AndroidCryptoProvider.java

@@ -67,14 +67,12 @@ public class AndroidCryptoProvider implements LimelightCryptoProvider {
             return null;
         }
 
-        try {
+        try (final FileInputStream fin = new FileInputStream(f)) {
-            FileInputStream fin = new FileInputStream(f);
             byte[] fileData = new byte[(int) f.length()];
             if (fin.read(fileData) != f.length()) {
                 // Failed to read
                 fileData = null;
             }
-            fin.close();
             return fileData;
         } catch (IOException e) {
             return null;
@@ -160,32 +158,28 @@ public class AndroidCryptoProvider implements LimelightCryptoProvider {
     }
 
     private void saveCertKeyPair() {
-        try {
+        try (final FileOutputStream certOut = new FileOutputStream(certFile);
-            FileOutputStream certOut = new FileOutputStream(certFile);
+             final FileOutputStream keyOut = new FileOutputStream(keyFile)
-            FileOutputStream keyOut = new FileOutputStream(keyFile);
+        ) {
-
             // Write the certificate in OpenSSL PEM format (important for the server)
             StringWriter strWriter = new StringWriter();
-            JcaPEMWriter pemWriter = new JcaPEMWriter(strWriter);
+            try (final JcaPEMWriter pemWriter = new JcaPEMWriter(strWriter)) {
-            pemWriter.writeObject(cert);
+                pemWriter.writeObject(cert);
-            pemWriter.close();
+            }
 
             // Line endings MUST be UNIX for the PC to accept the cert properly
-            OutputStreamWriter certWriter = new OutputStreamWriter(certOut);
+            try (final OutputStreamWriter certWriter = new OutputStreamWriter(certOut)) {
-            String pemStr = strWriter.getBuffer().toString();
+                String pemStr = strWriter.getBuffer().toString();
-            for (int i = 0; i < pemStr.length(); i++) {
+                for (int i = 0; i < pemStr.length(); i++) {
-                char c = pemStr.charAt(i);
+                    char c = pemStr.charAt(i);
-                if (c != '\r')
+                    if (c != '\r')
-                    certWriter.append(c);
+                        certWriter.append(c);
+                }
             }
-            certWriter.close();
 
             // Write the private out in PKCS8 format
             keyOut.write(key.getEncoded());
 
-            certOut.close();
-            keyOut.close();
-
             LimeLog.info("Saved generated key pair to disk");
         } catch (IOException e) {
             // This isn't good because it means we'll have

app/src/main/java/com/limelight/binding/video/MediaCodecHelper.java

@@ -887,8 +887,7 @@ public class MediaCodecHelper {
     
     public static String readCpuinfo() throws Exception {
         StringBuilder cpuInfo = new StringBuilder();
-        BufferedReader br = new BufferedReader(new FileReader(new File("/proc/cpuinfo")));
+        try (final BufferedReader br = new BufferedReader(new FileReader(new File("/proc/cpuinfo")))) {
-        try {
             for (;;) {
                 int ch = br.read();
                 if (ch == -1)
@@ -897,8 +896,6 @@ public class MediaCodecHelper {
             }
 
             return cpuInfo.toString();
-        } finally {
-            br.close();
         }
     }
     

app/src/main/java/com/limelight/computers/ComputerDatabaseManager.java

@@ -136,28 +136,26 @@ public class ComputerDatabaseManager {
     }
 
     public List<ComputerDetails> getAllComputers() {
-        Cursor c = computerDb.rawQuery("SELECT * FROM "+COMPUTER_TABLE_NAME, null);
+        try (final Cursor c = computerDb.rawQuery("SELECT * FROM "+COMPUTER_TABLE_NAME, null)) {
-        LinkedList<ComputerDetails> computerList = new LinkedList<>();
+            LinkedList<ComputerDetails> computerList = new LinkedList<>();
-        while (c.moveToNext()) {
+            while (c.moveToNext()) {
-            computerList.add(getComputerFromCursor(c));
+                computerList.add(getComputerFromCursor(c));
+            }
+            return computerList;
         }
-
-        c.close();
-
-        return computerList;
     }
 
     public ComputerDetails getComputerByUUID(String uuid) {
-        Cursor c = computerDb.query(COMPUTER_TABLE_NAME, null, COMPUTER_UUID_COLUMN_NAME+"=?", new String[]{ uuid }, null, null, null);
+        try (final Cursor c = computerDb.query(
-        if (!c.moveToFirst()) {
+                COMPUTER_TABLE_NAME, null, COMPUTER_UUID_COLUMN_NAME+"=?",
-            // No matching computer
+                new String[]{ uuid }, null, null, null)
-            c.close();
+        ) {
-            return null;
+            if (!c.moveToFirst()) {
+                // No matching computer
+                return null;
+            }
+
+            return getComputerFromCursor(c);
         }
-
-        ComputerDetails details = getComputerFromCursor(c);
-        c.close();
-
-        return details;
     }
 }

app/src/main/java/com/limelight/computers/ComputerManagerService.java

@@ -849,18 +849,12 @@ public class ComputerManagerService extends Service {
                             if (!appList.isEmpty() &&
                                     (!list.isEmpty() || emptyAppListResponses >= EMPTY_LIST_THRESHOLD)) {
                                 // Open the cache file
-                                OutputStream cacheOut = null;
+                                try (final OutputStream cacheOut = CacheHelper.openCacheFileForOutput(
-                                try {
+                                        getCacheDir(), "applist", computer.uuid)
-                                    cacheOut = CacheHelper.openCacheFileForOutput(getCacheDir(), "applist", computer.uuid);
+                                ) {
                                     CacheHelper.writeStringToOutputStream(cacheOut, appList);
                                 } catch (IOException e) {
                                     e.printStackTrace();
-                                } finally {
-                                    try {
-                                        if (cacheOut != null) {
-                                            cacheOut.close();
-                                        }
-                                    } catch (IOException ignored) {}
                                 }
 
                                 // Reset empty count if it wasn't empty this time

app/src/main/java/com/limelight/computers/IdentityManager.java

@@ -33,12 +33,11 @@ public class IdentityManager {
     private static String loadUniqueId(Context c) {
         // 2 Hex digits per byte
         char[] uid = new char[UID_SIZE_IN_BYTES * 2];
-        InputStreamReader reader = null;
         LimeLog.info("Reading UID from disk");
-        try {
+        try (final InputStreamReader reader =
-            reader = new InputStreamReader(c.openFileInput(UNIQUE_ID_FILE_NAME));
+                     new InputStreamReader(c.openFileInput(UNIQUE_ID_FILE_NAME))
-            if (reader.read(uid) != UID_SIZE_IN_BYTES * 2)
+        ) {
-            {
+            if (reader.read(uid) != UID_SIZE_IN_BYTES * 2) {
                 LimeLog.severe("UID file data is truncated");
                 return null;
             }
@@ -50,12 +49,6 @@ public class IdentityManager {
             LimeLog.severe("Error while reading UID file");
             e.printStackTrace();
             return null;
-        } finally {
-            if (reader != null) {
-                try {
-                    reader.close();
-                } catch (IOException ignored) {}
-            }
         }
     }
 
@@ -64,20 +57,14 @@ public class IdentityManager {
         LimeLog.info("Generating new UID");
         String uidStr = String.format((Locale)null, "%016x", new Random().nextLong());
 
-        OutputStreamWriter writer = null;
+        try (final OutputStreamWriter writer =
-        try {
+                     new OutputStreamWriter(c.openFileOutput(UNIQUE_ID_FILE_NAME, 0))
-            writer = new OutputStreamWriter(c.openFileOutput(UNIQUE_ID_FILE_NAME, 0));
+        ) {
             writer.write(uidStr);
             LimeLog.info("UID written to disk");
         } catch (IOException e) {
             LimeLog.severe("Error while writing UID file");
             e.printStackTrace();
-        } finally {
-            if (writer != null) {
-                try {
-                    writer.close();
-                } catch (IOException ignored) {}
-            }
         }
 
         // We can return a UID even if I/O fails

app/src/main/java/com/limelight/computers/LegacyDatabaseReader.java

@@ -68,37 +68,34 @@ public class LegacyDatabaseReader {
     }
 
     private static List<ComputerDetails> getAllComputers(SQLiteDatabase db) {
-        Cursor c = db.rawQuery("SELECT * FROM " + COMPUTER_TABLE_NAME, null);
+        try (final Cursor c = db.rawQuery("SELECT * FROM " + COMPUTER_TABLE_NAME, null)) {
-        LinkedList<ComputerDetails> computerList = new LinkedList<>();
+            LinkedList<ComputerDetails> computerList = new LinkedList<>();
-        while (c.moveToNext()) {
+            while (c.moveToNext()) {
-            ComputerDetails details = getComputerFromCursor(c);
+                ComputerDetails details = getComputerFromCursor(c);
 
-            // If a critical field is corrupt or missing, skip the database entry
+                // If a critical field is corrupt or missing, skip the database entry
-            if (details.uuid == null) {
+                if (details.uuid == null) {
-                continue;
+                    continue;
+                }
+
+                computerList.add(details);
             }
 
-            computerList.add(details);
+            return computerList;
         }
-
-        c.close();
-
-        return computerList;
     }
 
     public static List<ComputerDetails> migrateAllComputers(Context c) {
-        SQLiteDatabase computerDb = null;
+        try (final SQLiteDatabase computerDb = SQLiteDatabase.openDatabase(
-        try {
+                c.getDatabasePath(COMPUTER_DB_NAME).getPath(),
+                null, SQLiteDatabase.OPEN_READONLY)
+        ) {
             // Open the existing database
-            computerDb = SQLiteDatabase.openDatabase(c.getDatabasePath(COMPUTER_DB_NAME).getPath(), null, SQLiteDatabase.OPEN_READONLY);
             return getAllComputers(computerDb);
         } catch (SQLiteException e) {
             return new LinkedList<ComputerDetails>();
         } finally {
             // Close and delete the old DB
-            if (computerDb != null) {
-                computerDb.close();
-            }
             c.deleteDatabase(COMPUTER_DB_NAME);
         }
     }

app/src/main/java/com/limelight/computers/LegacyDatabaseReader2.java

@@ -49,37 +49,34 @@ public class LegacyDatabaseReader2 {
     }
 
     public static List<ComputerDetails> getAllComputers(SQLiteDatabase computerDb) {
-        Cursor c = computerDb.rawQuery("SELECT * FROM "+COMPUTER_TABLE_NAME, null);
+        try (final Cursor c = computerDb.rawQuery("SELECT * FROM "+COMPUTER_TABLE_NAME, null)) {
-        LinkedList<ComputerDetails> computerList = new LinkedList<>();
+            LinkedList<ComputerDetails> computerList = new LinkedList<>();
-        while (c.moveToNext()) {
+            while (c.moveToNext()) {
-            ComputerDetails details = getComputerFromCursor(c);
+                ComputerDetails details = getComputerFromCursor(c);
 
-            // If a critical field is corrupt or missing, skip the database entry
+                // If a critical field is corrupt or missing, skip the database entry
-            if (details.uuid == null) {
+                if (details.uuid == null) {
-                continue;
+                    continue;
+                }
+
+                computerList.add(details);
             }
 
-            computerList.add(details);
+            return computerList;
         }
-
-        c.close();
-
-        return computerList;
     }
 
     public static List<ComputerDetails> migrateAllComputers(Context c) {
-        SQLiteDatabase computerDb = null;
+        try (final SQLiteDatabase computerDb = SQLiteDatabase.openDatabase(
-        try {
+                c.getDatabasePath(COMPUTER_DB_NAME).getPath(),
+                null, SQLiteDatabase.OPEN_READONLY)
+        ) {
             // Open the existing database
-            computerDb = SQLiteDatabase.openDatabase(c.getDatabasePath(COMPUTER_DB_NAME).getPath(), null, SQLiteDatabase.OPEN_READONLY);
             return getAllComputers(computerDb);
         } catch (SQLiteException e) {
             return new LinkedList<ComputerDetails>();
         } finally {
             // Close and delete the old DB
-            if (computerDb != null) {
-                computerDb.close();
-            }
             c.deleteDatabase(COMPUTER_DB_NAME);
         }
     }

app/src/main/java/com/limelight/grid/assets/DiskAssetLoader.java

@@ -154,21 +154,15 @@ public class DiskAssetLoader {
     }
 
     public void populateCacheWithStream(CachedAppAssetLoader.LoaderTuple tuple, InputStream input) {
-        OutputStream out = null;
         boolean success = false;
-        try {
+        try (final OutputStream out = CacheHelper.openCacheFileForOutput(
-            out = CacheHelper.openCacheFileForOutput(cacheDir, "boxart", tuple.computer.uuid, tuple.app.getAppId() + ".png");
+                cacheDir, "boxart", tuple.computer.uuid, tuple.app.getAppId() + ".png")
+        ) {
             CacheHelper.writeInputStreamToOutputStream(input, out, MAX_ASSET_SIZE);
             success = true;
         } catch (IOException e) {
             e.printStackTrace();
         } finally {
-            if (out != null) {
-                try {
-                    out.close();
-                } catch (IOException ignored) {}
-            }
-
             if (!success) {
                 LimeLog.warning("Unable to populate cache with tuple: "+tuple);
                 CacheHelper.deleteCacheFile(cacheDir, "boxart", tuple.computer.uuid, tuple.app.getAppId() + ".png");

app/src/main/java/com/limelight/nvstream/http/NvHTTP.java

@@ -627,10 +627,9 @@ public class NvHTTP {
             return getAppListByReader(new StringReader(getAppListRaw()));
         }
         else {
-            ResponseBody resp = openHttpConnection(baseUrlHttps, "applist", true);
+            try (final ResponseBody resp = openHttpConnection(baseUrlHttps, "applist", true)) {
-            LinkedList<NvApp> appList = getAppListByReader(new InputStreamReader(resp.byteStream()));
+                return getAppListByReader(new InputStreamReader(resp.byteStream()));
-            resp.close();
+            }
-            return appList;
         }
     }
 

app/src/main/java/com/limelight/nvstream/wol/WakeOnLanSender.java

@@ -17,12 +17,11 @@ public class WakeOnLanSender {
     };
     
     public static void sendWolPacket(ComputerDetails computer) throws IOException {
-        DatagramSocket sock = new DatagramSocket(0);
         byte[] payload = createWolPayload(computer);
         IOException lastException = null;
         boolean sentWolPacket = false;
 
-        try {
+        try (final DatagramSocket sock = new DatagramSocket(0)) {
             // Try all resolved remote and local addresses and IPv4 broadcast address.
             // The broadcast address is required to avoid stale ARP cache entries
             // making the sleeping machine unreachable.
@@ -52,8 +51,6 @@ public class WakeOnLanSender {
                     lastException = e;
                 }
             }
-        } finally {
-            sock.close();
         }
 
         // Propagate the DNS resolution exception if we didn't
@@ -65,18 +62,20 @@ public class WakeOnLanSender {
     
     private static byte[] macStringToBytes(String macAddress) {
         byte[] macBytes = new byte[6];
-        @SuppressWarnings("resource")
+
-        Scanner scan = new Scanner(macAddress).useDelimiter(":");
+        try (@SuppressWarnings("resource")
-        for (int i = 0; i < macBytes.length && scan.hasNext(); i++) {
+             final Scanner scan = new Scanner(macAddress).useDelimiter(":")
-            try {
+        ) {
-                macBytes[i] = (byte) Integer.parseInt(scan.next(), 16);
+            for (int i = 0; i < macBytes.length && scan.hasNext(); i++) {
-            } catch (NumberFormatException e) {
+                try {
-                LimeLog.warning("Malformed MAC address: "+macAddress+" (index: "+i+")");
+                    macBytes[i] = (byte) Integer.parseInt(scan.next(), 16);
-                break;
+                } catch (NumberFormatException e) {
+                    LimeLog.warning("Malformed MAC address: " + macAddress + " (index: " + i + ")");
+                    break;
+                }
             }
+            return macBytes;
         }
-        scan.close();
-        return macBytes;
     }
     
     private static byte[] createWolPayload(ComputerDetails computer) {