ByteArrayUtil.java

package com.yahoo.dtf.util;

public class ByteArrayUtil {

    public static String byteArrayToHexString(byte in[]) {
        return byteArrayToHexString(in, in.length);
    }
    
    public static String byteArrayToHexString(byte in[], int length) {
        byte ch = 0x00;
        int i = 0;

        if (in == null || in.length <= 0)
            return null;

        String pseudo[] = {"0", "1", "2", "3", "4", "5", "6", "7",
                           "8", "9", "A", "B", "C", "D", "E", "F" };

        StringBuffer out = new StringBuffer(in.length * 2);

        while (i < length) {
            ch = (byte) (in[i] & 0xF0); // Strip off high nibble
            ch = (byte) (ch >>> 4);
            // shift the bits down
            
            ch = (byte) (ch & 0x0F);
            // must do this is high order bit is on!
            out.append(pseudo[(int) ch]); // convert the nibble to a String
                                            // Character

            ch = (byte) (in[i] & 0x0F); // Strip off low nibble
            out.append(pseudo[(int) ch]); // convert the nibble to a String
                                            // Character
            i++;
        }
        
        String rslt = new String(out);
        return rslt;
    }    
    
    public static byte[] hexToByteArray(String hexString) { 
        byte[] bytes = new byte[hexString.length() / 2];
       
        for (int i = 0; i < bytes.length; i++) {
           bytes[i] = (byte)Integer.parseInt(hexString.substring(2*i, 2*i+2), 16);
        } 
        
        return bytes;
    }
    
}