lockfile for android

FileLocker.java

package test.demo;

import java.io.File;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.util.Date;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

/**
 * @author fredrik persson
 * a quick android version, writing to /mnt/sdcard
 */
public class demo extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Log.i("Demo", "Locking file...");
		Date now = new Date();
		File file = new File("/mnt/sdcard/myfile");
		try{
			FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
			FileLock lock = channel.lock();			
			if(!file.exists()){
				file.createNewFile();
				Log.i("Demo","Createing file");
			}else{
				Log.i("Demo","modify file");
				file.setLastModified(now.getTime());
			}
			lock.release();
			channel.close();
		}catch(Exception e){
			Log.i("Demo","Err: "+e.getMessage());
		}
		
		try {
			Thread.sleep(5000);
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		Log.i("Demo","Current unixtime is: "+Long.toString(now.getTime()));
		Log.i("Demo","File last modified:" +Long.toString(file.lastModified()));
	}
}