package com.foxinmy.weixin4j.util;
   
   /**
    * Hex工具类
    * 
    * @className HexUtil
    * @author jinyu(foxinmy@gmail.com)
    * @date 2015年5月17日
    * @since JDK 1.6
   * @see
   */
  public final class HexUtil {
  	/**
  	 * Used to build output as Hex
  	 */
  	private static final char[] DIGITS_LOWER = { '0', '1', '2', '3', '4', '5',
  			'6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
  
  	/**
  	 * Used to build output as Hex
  	 */
  	private static final char[] DIGITS_UPPER = { '0', '1', '2', '3', '4', '5',
  			'6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
  
  	private static char[] encodeHex(final byte[] data, final char[] toDigits) {
  		final int l = data.length;
  		final char[] out = new char[l << 1];
  		// two characters form the hex value.
  		for (int i = 0, j = 0; i < l; i++) {
  			out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
  			out[j++] = toDigits[0x0F & data[i]];
  		}
  		return out;
  	}
  
  	public static String encodeHexString(final byte[] data) {
  		return new String(encodeHex(data, true));
  	}
  
  	public static char[] encodeHex(final byte[] data, final boolean toLowerCase) {
  		return encodeHex(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
  	}
  }