Java FileLock trylock(File file, boolean shared)

Description

Use unlock to release lock and avoid channel leaks.

License

Apache License

Parameter

Parameter	Description
file	a parameter
shared	a parameter

Exception

Parameter	Description
IOException	an exception

Return

lock or null if lock is being held by someone else

Declaration

public static FileLock trylock(File file, boolean shared) throws IOException 

Method Source Code

//package com.java2s;
/*//from   w  w  w. j  a  v  a2s  .c o m
 * Copyright 2012 Johns Hopkins University
 *
 * 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.
 */

import java.io.File;
import java.io.IOException;

import java.io.RandomAccessFile;

import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;

public class Main {
    /**
     * Use unlock to release lock and avoid channel leaks.
     * 
     * @param file
     * @param shared
     * @return lock or null if lock is being held by someone else
     * @throws IOException
     */
    public static FileLock trylock(File file, boolean shared) throws IOException {
        FileChannel chan = new RandomAccessFile(file, "rw").getChannel();
        return chan.tryLock(0, Long.MAX_VALUE, shared);
    }
}

Related

1. releaseQuietly(FileLock lock)
2. releaseQuietly(final FileLock lock)
3. releaseSilent(FileLock fileLock)
4. setNonBlockingFD(Channel c, boolean blocking)
5. tryLock(File file)
6. tryLock(File location)
7. unblockSocket(SelectableChannel... channels)
8. unlock(File file)
9. unlock(FileLock lock)