对于大文件的读写操作

import java.io.*;
import java.nio.*;
import java.nio.channels.*;

public class LargeMappedFiles
{

static int length = 0x8FFFFFF;
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.println((char)out.get(i));
}

}