randomaccessfiletest.java

疯狂Java讲义_源码(含Java设计模式CHM

import java.io.*;

/**
 * Description:
 * <br/>Copyright (C), 2005-2008, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee [e-mail]
 * @version  1.0
 */
public class RandomAccessFileTest
{
	public static void main(String[] args) 
	{
		RandomAccessFile raf = null;
		try
		{
			//以只读方式打开一个RandomAccessFile对象
			raf = new RandomAccessFile("RandomAccessFileTest.java" , "r");
			//获取RandomAccessFile对象文件指针的位置，初始位置是0
			System.out.println("RandomAccessFile的文件指针的初始位置：" 
				+ raf.getFilePointer());
			//移动raf的文件记录指针的位置
			raf.seek(300);
			byte[] bbuf = new byte[1024];
			//用于保存实际读取的字节数
			int hasRead = 0;
			//使用循环来重复“取水”过程
			while ((hasRead = raf.read(bbuf)) > 0 )
			{
				//取出“竹筒”中水滴（字节），将字节数组转换成字符串输出！
				System.out.print(new String(bbuf , 0 , hasRead ));
			}
		}
		catch (IOException ex)
		{
			ex.printStackTrace();
		}
		finally
		{
			try
			{
				if (raf != null)
				{
					raf.close();
				}
			}
			catch (IOException ex)
			{
				ex.printStackTrace();
			}
		}

	}
}