Filelock to implement lock function on file

The use of filelock in a multithreaded environment to achieve the lock function of the file, to avoid multiple threads simultaneously operating the same file,

Program:

public class demo{

Filelock lock;

/* Read/write file * *

Public Rwfile () {

Lock=trylock ();

if (lock!=null) {

Lock succeeded

You can work with the file.

Unlock ();

}else{

Lock failure

}

}

/* Lock operation return NON-EMPTY = Lock Success * *

Private Filelock Trylock () throws IOException {

File LOCKF = new file (root, "xxx.dat"); The file to lock

Lockf.deleteonexit (); Specifies that the lock is released when exiting

Randomaccessfile file = new Randomaccessfile (LOCKF, "RWS"); Specify the file to lock

Filelock res = null;

try {

res = File.getchannel (). Trylock (); Attempt to get a lock on the file

The catch (overlappingfilelockexception oe) {//file is thrown by another thread lock

File.close ();

return null;

catch (IOException e) {

Log.error ("Cannot create lock on" + LOCKF, E);

File.close ();

Throw e;

}

return res;

}

/* Unlock Operation * *

private void Unlock () throws IOException {

if (This.lock = null)

Return

This.lock.release ();

Lock.channel (). Close ();

lock = null;

}

}