How do I convert a character into binary?

Question

How would you convert a given character in a string to a its corresponding binary value?

public void send(DataFrame frame) {
    String bitString = frame.toString();
        for (int a = 0; a < bitString.length(); a++) {
            char c = bitString.charAt(a);
            ????
    }
}

where frame is defined to be a byte array (as byte [] in the DataFrame class

Solution

String binaryString = Integer.toBinaryString(0x100 + bytes[i]).substring(2);