// : c12:LargeMappedFiles.java
// Creating a very large file using mapping.
// {RunByHand}
// {Clean: test.dat}
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
public class LargeMappedFiles {
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));
}
} ///:~