Content byte[] array to hex string

 
public class Main {
  public static final String toHexString( byte[] res )
  {
      StringBuffer buf = new StringBuffer( res.length << 1 );

      for ( int ii = 0; ii < res.length; ii++ )
      {
          String digit = Integer.toHexString( 0xFF & res[ii] );

          if ( digit.length() == 1 )
          {
              digit = '0' + digit;
          }

          buf.append( digit );
      }
      return buf.toString().toUpperCase();
  }
}
  

 
import java.security.SecureRandom;
import java.util.Random;

public class Main
{

  public static String toHexString( byte[] bytes )
  {
      StringBuffer sb = new StringBuffer( bytes.length*2 );
      for( int i = 0; i < bytes.length; i++ )
      {
          sb.append( toHex(bytes[i] >> 4) );
          sb.append( toHex(bytes[i]) );
      }

      return sb.toString();
  }
  private static char toHex(int nibble)
  {
      final char[] hexDigit =
      {
          '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
      };
      return hexDigit[nibble & 0xF];
  }


}