Java基础之IO流，自定义字节流缓冲区装饰类（模仿）

import java.io.*;

/*
    自定义缓冲区
*/
class MyBufferedInputStreamDemo
{
    public static void main(String[] args)  throws IOException
    {
        MyBufferedInputStream mis = new MyBufferedInputStream(new FileInputStream(new File("001.avi")));
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(new File("001-1.avi")));
        
        int ch = 0;
        while((ch=mis.read())!=-1)
        {
            bos.write(ch);
        }
        
        mis.close();
        bos.close();
    }
}

class MyBufferedInputStream
{
    private InputStream inputStream = null;
    private byte[] buffer = new byte[1024 * 4];
    private int pos = 0,count=0;
    
    public MyBufferedInputStream(InputStream inputStream) throws IOException
    {
        this.inputStream = inputStream;
    }
    
    public int read() throws IOException
    {
        //如果结果长度为零，则从流中读取数据
        if(count==0)
        {
            //读取数据被放入字节数组中
            count = this.inputStream.read(buffer);    
            
            //如果读取的结果长度为-1，说明文件读取完成
            if(count<0)
                return -1;
            
            //每次重新从流中取数据时，将指针重置为0
            pos = 0;
            
            byte b = buffer[pos];            
            count--;
            pos++;
            return b&0xff;
        }
        else
        {
            byte b = buffer[pos];            
            count--;
            pos++;
            return b&0xff;
        }
    }
    
    public void close() throws IOException
    {
        this.inputStream.close();
    }
}