File Java Tutorial

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
public class MainClass {
  public static void main(String[] args) throws IOException {
    FileInputStream inFile = new FileInputStream(args[0]);
    FileOutputStream outFile = new FileOutputStream(args[1]);
    FileChannel inChannel = inFile.getChannel();
    FileChannel outChannel = outFile.getChannel();
    FileLock outLock = outChannel.lock();
    FileLock inLock = inChannel.lock(0, inChannel.size(), true);
    inChannel.transferTo(0, inChannel.size(), outChannel);
    outLock.release();
    inLock.release();
    inChannel.close();
    outChannel.close();
  }
}