将java的字节转换成二进制串，主要是利用了toBinaryString(int i) 这个函数

CountBytes

public class CountBytes {

	public static void main(String[] args) throws IOException {
		InputStream in;
		if (args.length == 0){
			in = System.in;			
		}else
			in = new FileInputStream(args[0]);
		byte[] buff = new byte[10];
		int total = 0;
		while (in.read(buff, 0, buff.length) != -1){
			total++;
		}
		System.out.println(total + "  bytes");
		for (byte i : buff){
			String s = byte2bits(i);
			System.out.print(s);
//			System.out.println(i + ":");
		}
		System.out.println();
	}
	
		
	public static BitSet fromByte(byte b)
	{
	    BitSet bits = new BitSet(8);
	    for (int i = 0; i < 8; i++)
	    {
	        bits.set(i, (b & 1) == 1);
	        b >>= 1;
	    }
	    return bits;
	}
	
	public static String byte2bits(byte b) {
		int z = b; z |= 256;
		String str = Integer.toBinaryString(z);
		int len = str.length();
		return str.substring(len-8, len);
		}
}

thank you.