位置读取文件

import java.io.*;
//基于位置的读和写
public class Demo04
{
    public static void main(String s[])
    {
        try
        {//1  文件名    2  rw  read and write
            RandomAccessFile raf1 = new RandomAccessFile("Demo04.java","rw");
            RandomAccessFile raf2 = new RandomAccessFile("Demo04.txt","rw");
            
            long length = raf1.length()/4;//从第几个字符开始读取，包括几
            //定位到某个位置
            raf1.seek(length);//设置起始位置
            int data;
            //循环进行读和写
            while((data=raf1.read())!=-1)
            {
                raf2.write(data);
                System.out.print((char)data);
                Thread.sleep(20);
            }
            raf1.close();
            raf2.close();
        }
        catch(Exception e)
        {
            System.out.println(e.getMessage());
            e.printStackTrace();
        }
    }
}