Example usage for java.nio.channels FileLock isShared

Introduction

In this page you can find the example usage for java.nio.channels FileLock isShared.

Prototype

public final boolean isShared() 

Source Link

Document

Tells whether this lock is shared.

Usage

From source file:Main.java

public static void main(String[] argv) throws Exception {
    File file = new File("filename");
    FileChannel channel = new RandomAccessFile(file, "rw").getChannel();

    FileLock lock = channel.lock(0, Long.MAX_VALUE, true);

    lock = channel.tryLock(0, Long.MAX_VALUE, true);

    boolean isShared = lock.isShared();

    lock.release();/*from   w w w  .j  a  v  a2  s .c  o  m*/

    channel.close();
}

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From source file:ca.uviccscu.lp.server.main.ShutdownListener.java

@Deprecated
public void releaseLocks() {
    l.trace("Trying to check file locks ");
    try {/*from   w w w  .  j a  v a  2  s. co  m*/
        Collection c = FileUtils.listFiles(new File(Shared.workingDirectory), null, true);
        Object[] arr = c.toArray();
        for (int i = 0; i < arr.length; i++) {
            l.trace("Trying lock for: " + ((File) arr[i]).getAbsolutePath());
            // Get a file channel for the file
            File file = ((File) arr[i]);
            FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
            // Use the file channel to create a lock on the file.
            // This method blocks until it can retrieve the lock.
            //FileLock lock = channel.lock();
            // Try acquiring the lock without blocking. This method returns
            // null or throws an exception if the file is already locked.
            FileLock lock = null;
            try {
                lock = channel.lock();
            } catch (OverlappingFileLockException ex) {
                l.trace("Lock already exists", ex);
            }
            if (lock == null) {
                l.trace("Lock failed - someone else holds lock");
            } else {
                l.trace("Lock shared: " + lock.isShared() + " Lock valid: " + lock.isValid());
                lock.release();
                l.trace("Lock release OK");
                try {
                    if (!file.delete()) {
                        throw new IOException();
                    }
                } catch (Exception e) {
                    l.trace("Delete failed", e);
                }
            }
        }
        //Thread.sleep(25000);

    } catch (Exception e) {
        // File is already locked in this thread or virtual machine
        l.trace("File lock problem", e);
    }
}

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