import java.io.*;class MyBufferedInputStream{        private InputStream in;    private byte[] buf = byte[1024*4];    private int pos = 0,count = 0;//指针，计数器        MyBufferedInputStream(InputStream in)    {            this.in=in;    }        public int myRead()    {        if(count==0){            count = in.read(buf);//读取字符流，存入数组            if(count<0)            //结尾                return -1;            pos=0;            byte b= buf[pos];            count--;            pos++;            return b&0xff;        }else if (count>0){            byte b= buf[pos];            count--;            pos++;            return b&0xff;//避免文件中连续八个1，返回后为-1        }        return -1;    }    public void myClose()throws IOException    {        in.close();    }}

利用数组，模拟字符流缓冲区