Java Programming

Hi,

i've found a nice function which converts my byte array to a hex string.

   static char[] hexChar = {
	        '0' , '1' , '2' , '3' ,
	        '4' , '5' , '6' , '7' ,
	        '8' , '9' , 'A' , 'B' ,
	        'C' , 'D' , 'E' , 'F' 
   };

	public static String toHexString ( byte[] b ) {
	    StringBuffer sb = new StringBuffer( b.length * 2 );
	    for ( int i=0; i<b.length; i++ ) {
	        // look up high nibble char
	        sb.append( hexChar [( b[i] & 0xf0 ) >>> 4] ); // fill left with zero bits

	        // look up low nibble char
	        sb.append( hexChar [b[i] & 0x0f] );
	    }
	    return sb.toString();
   }

It's working fine, but i need the conversion in the other direction. It should be very easy, but i didn't get it.
I first tried to use simply

 byte[] bArray = hexStr.getBytes();

but it seems to be something different.

But why is it different?