Java tutorial
import java.io.File; import java.io.RandomAccessFile; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; public class Main { public static void main(String[] argv) throws Exception { FileChannel rwChannel = new RandomAccessFile(new File("test.txt"), "rw").getChannel(); FileChannel roChannel = new RandomAccessFile(new File("test.txt"), "r").getChannel(); FileChannel pvChannel = new RandomAccessFile(new File("text.txt"), "rw").getChannel(); ByteBuffer pvBuf = roChannel.map(FileChannel.MapMode.READ_WRITE, 0, (int) rwChannel.size()); } }