String str = "鲸";

        char[] chars = "0123456789ABCDEF".toCharArray();

        StringBuilder builder = new StringBuilder("");

        byte[] bs = str.getBytes();

        int bit;

        for (int i = 0; i < bs.length; i++) {

            bit = (bs[i] & 0x0f0) >> 4;

            builder.append(chars[bit]);

            bit = bs[i] & 0x0f;

            builder.append(chars[bit]);

            builder.append(' ');

        }

        System.out.println(builder.toString().trim());