BigFileIO.java

package com.e2u.perf;

import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;

public class BigFileIO
{
	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));// read file
	} // /
}