import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
public class MainClass {
static int length = 0x8FFFFFF; // 128 Mb
public static void main(String[] args) throws Exception {
MappedByteBuffer out = new RandomAccessFile("test.dat", "rw").getChannel().map(
FileChannel.MapMode.READ_WRITE, 0, length);
for (int i = 0; i < length; i++)
out.put((byte) 'x');
System.out.println("Finished writing");
for (int i = length / 2; i < length / 2 + 6; i++)
System.out.print((char) out.get(i));
}
}