/* 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;
/*
* Returns 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()
*/
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()
*/
public void release() throws IOException {
if (!channel().isOpen()) {
throw new ClosedChannelException();
}
if (!isReleased) {
((FileChannelImpl) channel()).release(this);
isReleased = true;
}
}
}
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