| /* Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| |
| package org.apache.harmony.nio.internal; |
| |
| import java.io.IOException; |
| import java.nio.channels.ClosedChannelException; |
| import java.nio.channels.FileChannel; |
| import java.nio.channels.FileLock; |
| |
| /** |
| * The concrete implementation of an NIO file lock object. |
| */ |
| final class FileLockImpl extends FileLock { |
| |
| // Remembers if this lock has been released via the API. |
| private boolean isReleased = false; |
| |
| /** |
| * Constructs a new file lock object with the given parameters. |
| * |
| * @param channel |
| * the file channel hosting the lock. |
| * @param position |
| * the start position of the lock, in bytes |
| * @param size |
| * the length of the lock, in bytes |
| * @param shared |
| * whether this lock is shared (true) or exclusive (false) |
| */ |
| public FileLockImpl(FileChannel channel, long position, long size, boolean shared) { |
| super(channel, position, size, shared); |
| } |
| |
| /** |
| * Tests to see if the lock is valid. A lock can be invalidated if the |
| * channel it is acquired on is closed or if it is released. (non-Javadoc) |
| * |
| * @see java.nio.channels.FileLock#isValid() |
| */ |
| @Override |
| public boolean isValid() { |
| return !isReleased && channel().isOpen(); |
| } |
| |
| /** |
| * Releases the file lock on the channel that acquired it. Releasing an |
| * invalid lock has no effect. |
| * |
| * @see java.nio.channels.FileLock#release() |
| */ |
| @Override |
| public void release() throws IOException { |
| if (!channel().isOpen()) { |
| throw new ClosedChannelException(); |
| } |
| |
| if (!isReleased) { |
| ((FileChannelImpl) channel()).release(this); |
| isReleased = true; |
| } |
| } |
| } |