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 {
File file = new File("filename");
FileChannel roChannel = new RandomAccessFile(file, "r").getChannel();
ByteBuffer roBuf = roChannel.map(FileChannel.MapMode.READ_ONLY, 0, (int) roChannel.size());
}
}