checkstyle: enable and apply FinalClass

F-Droid/src/org/fdroid/fdroid/AppDetails.java

@@ -704,7 +704,7 @@ public class AppDetails extends AppCompatActivity implements ProgressListener, A
         startActivity(intent);
     }
 
-    private static class SafeLinkMovementMethod extends LinkMovementMethod {
+    private static final class SafeLinkMovementMethod extends LinkMovementMethod {
 
         private static SafeLinkMovementMethod instance;
 

F-Droid/src/org/fdroid/fdroid/Preferences.java

@@ -21,7 +21,7 @@ import java.util.Random;
  * accessed via the {@link org.fdroid.fdroid.Preferences#get()}
  * singleton method.
  */
-public class Preferences implements SharedPreferences.OnSharedPreferenceChangeListener {
+public final class Preferences implements SharedPreferences.OnSharedPreferenceChangeListener {
 
     private static final String TAG = "Preferences";
 

F-Droid/src/org/fdroid/fdroid/Utils.java

@@ -421,7 +421,7 @@ public final class Utils {
         return repoAddress + "/" + apk.apkName.replace(" ", "%20");
     }
 
-    public static class CommaSeparatedList implements Iterable<String> {
+    public static final class CommaSeparatedList implements Iterable<String> {
         private final String value;
 
         private CommaSeparatedList(String list) {

F-Droid/src/org/fdroid/fdroid/localrepo/LocalRepoKeyStore.java

@@ -54,7 +54,7 @@ import kellinwood.security.zipsigner.ZipSigner;
 
 // TODO Address exception handling in a uniform way throughout
 
-public class LocalRepoKeyStore {
+public final class LocalRepoKeyStore {
 
     private static final String TAG = "LocalRepoKeyStore";
 
@@ -333,7 +333,7 @@ public class LocalRepoKeyStore {
      * for it's chosen server alias. All other operations are deferred to the
      * wrapped X509KeyManager.
      */
-    private static class KerplappKeyManager implements X509KeyManager {
+    private static final class KerplappKeyManager implements X509KeyManager {
         private final X509KeyManager wrapped;
 
         private KerplappKeyManager(X509KeyManager wrapped) {

F-Droid/src/org/fdroid/fdroid/localrepo/LocalRepoManager.java

@@ -62,7 +62,7 @@ import java.util.jar.JarOutputStream;
  * This class deals specifically with the webroot side of things, ensuring we have a valid index.jar
  * and the relevant .apk and icon files available.
  */
-public class LocalRepoManager {
+public final class LocalRepoManager {
     private static final String TAG = "LocalRepoManager";
 
     // For ref, official F-droid repo presently uses a maxage of 14 days

F-Droid/src/org/fdroid/fdroid/localrepo/type/BluetoothSwap.java

@@ -13,7 +13,7 @@ import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.localrepo.SwapService;
 import org.fdroid.fdroid.net.bluetooth.BluetoothServer;
 
-public class BluetoothSwap extends SwapType {
+public final class BluetoothSwap extends SwapType {
 
     private static final String TAG = "BluetoothSwap";
     public static final String BLUETOOTH_NAME_TAG = "FDroid:";

F-Droid/src/org/fdroid/fdroid/net/bluetooth/httpish/Request.java

@@ -12,8 +12,7 @@ import java.util.HashMap;
 import java.util.Locale;
 import java.util.Map;
 
-public class Request {
-
+public final class Request {
 
     private static final String TAG = "bluetooth.Request";
 

config/checkstyle/checkstyle.xml

@@ -60,7 +60,7 @@
         <!--<module name="InnerAssignment" />-->
         <!--<module name="MissingSwitchDefault" />-->
 
-        <!--<module name="FinalClass" />-->
+        <module name="FinalClass" />
         <!--<module name="HideUtilityClassConstructor" />-->
         <!--<module name="InterfaceIsType" />-->
         <!--<module name="VisibilityModifier" />-->