How to convert a byte array to a hex string in Java?

Question

I have a byte array filled with hex numbers and printing it the easy way is pretty pointless because there are many unprintable elements. What I need is the exact hexcode in

Answer 1

Here is a java.util.Base64-like implementation(partial), isn't it pretty?

public class Base16/*a.k.a. Hex*/ {
    public static class Encoder{
        private static char[] toLowerHex={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
        private static char[] toUpperHex={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
        private boolean upper;
        public Encoder(boolean upper) {
            this.upper=upper;
        }
        public String encode(byte[] data){
            char[] value=new char[data.length*2];
            char[] toHex=upper?toUpperHex:toLowerHex;
            for(int i=0,j=0;i>4];
                value[j++]=toHex[octet&0xF];
            }
            return new String(value);
        }
        static final Encoder LOWER=new Encoder(false);
        static final Encoder UPPER=new Encoder(true);
    }
    public static Encoder getEncoder(){
        return Encoder.LOWER;
    }
    public static Encoder getUpperEncoder(){
        return Encoder.UPPER;
    }
    //...
}