Java shim / QFS access:

* Implement new style java cleanup by use ref.Cleaner, while retaining the old style cleanup for backward compatibility.
* Rename all native classes by adding Base suffix.
* Implement two different subclasses for each of KfsAccess, KfsInputChannel, and KfsOutputChannel, one for the old style cleanup and one for the new style cleanup.
* Reformat the code to match the new style.
* Eliminate java compiler warnings.

Author: mikeov

src/cc/access/qfs_access_jni.cc

@@ -22,7 +22,7 @@
  * License for the specific language governing permissions and limitations under
  * the License.
  *
- * \brief Java wrappers to get to the KFS client.
+ * \brief QFS access java 9 style cleanup.
  */
 package com.quantcast.qfs.access;
 
@@ -37,25 +37,29 @@ static void registerCleanup(Object obj, Runnable action) {
         cleaner.register(obj, action);
     }
 
-    private void register() {
+    private static void registerCleanupSelf(KfsAccess ka) {
         // Ensure that the native resource is cleaned up when this object is
         // garbage collected.
-        // Make sure that this is not referenced by the cleaner closure
+        // Make sure that this and ka are not referenced by the cleaner closure
         // otherwise it will never be cleaned up.
-        final long ptr = getCPtr();
-        registerCleanup(this, () -> {
+        final long ptr = ka.getCPtr();
+        registerCleanup(ka, () -> {
             destroy(ptr);
         });
     }
 
+    private void registerCleanupConstructed() {
+        registerCleanupSelf(this);
+    }
+
     public KfsAccess(String configFn) throws IOException {
         super(configFn);
-        register();
+        registerCleanupConstructed();
     }
 
     public KfsAccess(String metaServerHost,
             int metaServerPort) throws IOException {
         super(metaServerHost, metaServerPort);
-        register();
+        registerCleanupConstructed();
     }
 }

src/java/qfs-access-9/src/main/java/com/quantcast/qfs/access/KfsAccess.java

@@ -0,0 +1,39 @@
+/**
+ * $Id$
+ *
+ * Created 2025/04/20
+ *
+ * @author: Mike Ovsiannikov (Quantcast Corporation)
+ *
+ * Copyright 2025 Quantcast Corporation. All rights reserved.
+ * Copyright 2007 Kosmix Corp.
+ *
+ * This file is part of Kosmos File System (KFS).
+ *
+ * Licensed under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ *
+ * \brief Input channel java 9 style cleanup.
+ */
+package com.quantcast.qfs.access;
+
+final public class KfsInputChannel extends KfsInputChannelBase {
+
+    KfsInputChannel(KfsAccessBase ka, int fd) {
+        super(ka, fd);
+        registerCleanup();
+    }
+
+    private void registerCleanup() {
+        KfsAccess.registerCleanup(this, state);
+    }
+}

src/java/qfs-access-9/src/main/java/com/quantcast/qfs/access/KfsInputChannel.java

@@ -0,0 +1,39 @@
+/**
+ * $Id$
+ *
+ * Created 2025/04/20
+ *
+ * @author: Mike Ovsiannikov (Quantcast Corporation)
+ *
+ * Copyright 2025 Quantcast Corporation. All rights reserved.
+ * Copyright 2007 Kosmix Corp.
+ *
+ * This file is part of Kosmos File System (KFS).
+ *
+ * Licensed under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ *
+ * \brief Input channel java 9 style cleanup.
+ */
+package com.quantcast.qfs.access;
+
+final public class KfsOutputChannel extends KfsOutputChannelBase {
+
+    KfsOutputChannel(KfsAccessBase ka, int fd) {
+        super(ka, fd);
+        registerCleanup();
+    }
+
+    private void registerCleanup() {
+        KfsAccess.registerCleanup(this, state);
+    }
+}

src/java/qfs-access-9/src/main/java/com/quantcast/qfs/access/KfsOutputChannel.java

@@ -28,22 +28,19 @@
 
 import java.io.IOException;
 
-final public class KfsAccess extends KfsAccessBase
-{
-    public KfsAccess(String configFn) throws IOException
-    {
+final public class KfsAccess extends KfsAccessBase {
+
+    public KfsAccess(String configFn) throws IOException {
         super(configFn);
     }
 
     public KfsAccess(String metaServerHost,
-            int metaServerPort) throws IOException
-    {
+            int metaServerPort) throws IOException {
         super(metaServerHost, metaServerPort);
     }
 
     @Override
-    protected void finalize() throws Throwable
-    {
+    protected void finalize() throws Throwable {
         try {
             kfs_destroy();
         } finally {