org.glassfish.common.util.admin
Class ManagedFile

java.lang.Object
  org.glassfish.common.util.admin.ManagedFile

public class ManagedFile
extends Object

Defines the notion of a managed file with a classic Read-Write locking policy. A managed file can be locked for multiple concurrent reads or a single write.

A simple example could follow this :

ManagedFile managedFile = new ManagedFile(new File(...), 1000, -1); Lock writeLock; try { writeLock = managedFile.writeAccess(); // write or delete the file } finally { writeLock.unlock(); }

Author:

Jerome Dochez

Nested Class Summary

static interface

ManagedFile.ManagedLock

Constructor Summary

ManagedFile(File file, int timeOut, int maxHoldingTime)
Creates a new managed file.

Method Summary

ManagedFile.ManagedLock	accessRead() Blocks for timeOut milliseconds for the read access to the managed file.
ManagedFile.ManagedLock	accessWrite() Blocks for timeOut milliseconds for the write access to the managed file.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ManagedFile

public ManagedFile(File file,
                   int timeOut,
                   int maxHoldingTime)
            throws IOException

Creates a new managed file.

Parameters:

file - the file to manage

timeOut - the max time in milliseconds to wait for a read or write lock

maxHoldingTime - the max time in milliseconds to hold the read or write lock

Throws:

IOException - when the file cannot be locked

Method Detail

accessWrite

public ManagedFile.ManagedLock accessWrite()
                                    throws IOException,
                                           TimeoutException

Blocks for timeOut milliseconds for the write access to the managed file.

Returns:

the lock instance on the locked file.

Throws:

IOException - if the file cannot be locked

TimeoutException - if the lock cannot be obtained before the timeOut expiration.

accessRead

public ManagedFile.ManagedLock accessRead()
                                   throws IOException,
                                          TimeoutException

Blocks for timeOut milliseconds for the read access to the managed file.

Returns:

the lock instance on the locked file.

Throws:

IOException - if the file cannot be locked

TimeoutException - if the lock cannot be obtained before the timeOut expiration.