Convert hexadecimal string (hex) to a binary string

Question

I found the following way hex to binary conversion:

String binAddr = Integer.toBinaryString(Integer.parseInt(hexAddr, 16)); 

While this app

Answer 1

Fast, and works for large strings:

    private String hexToBin(String hex){
        hex = hex.replaceAll("0", "0000");
        hex = hex.replaceAll("1", "0001");
        hex = hex.replaceAll("2", "0010");
        hex = hex.replaceAll("3", "0011");
        hex = hex.replaceAll("4", "0100");
        hex = hex.replaceAll("5", "0101");
        hex = hex.replaceAll("6", "0110");
        hex = hex.replaceAll("7", "0111");
        hex = hex.replaceAll("8", "1000");
        hex = hex.replaceAll("9", "1001");
        hex = hex.replaceAll("A", "1010");
        hex = hex.replaceAll("B", "1011");
        hex = hex.replaceAll("C", "1100");
        hex = hex.replaceAll("D", "1101");
        hex = hex.replaceAll("E", "1110");
        hex = hex.replaceAll("F", "1111");
        return hex;
    }