在文件上创建共享文件锁，创建共享文件锁,package com.

在文件上创建共享文件锁，创建共享文件锁,package com.

package com.javacodegeeks.snippets.core;import java.io.File;import java.io.IOException;import java.io.RandomAccessFile;import java.nio.channels.FileChannel;import java.nio.channels.FileLock;import java.nio.channels.OverlappingFileLockException;public class CreateSharedFileLockOnFile {    public static void main(String[] args) {        try {            File file = new File("fileToLock.dat");            // Creates a random access file stream to read from, and optionally to write to            FileChannel channel = new RandomAccessFile(file, "rw").getChannel();            // Acquire an exclusive lock on this channel's file ( block until the region can be            // locked, this channel is closed, or the invoking thread is interrupted)            FileLock lock = channel.lock(0, Long.MAX_VALUE, true);            // Attempts to acquire an exclusive lock on this channel's file (does not block, an            // invocation always returns immediately, either having acquired a lock on the requested            // region or having failed to do so.            try {                lock = channel.tryLock(0, Long.MAX_VALUE, true);            }            catch (OverlappingFileLockException e) {                // thrown when an attempt is made to acquire a lock on a a file that overlaps                // a region already locked by the same JVM or when another thread is already                // waiting to lock an overlapping region of the same file                System.out.println("Overlapping File Lock Error: " + e.getMessage());            }            // tells whether this lock is shared            boolean isShared = lock.isShared();            // release the lock            lock.release();            // close the channel            channel.close();        }        catch (IOException e) {            System.out.println("I/O Error: " + e.getMessage());        }    }}//该片段来自于http://byrx.net