字节数组转16进制字符串

 /*
* 字节数组转16进制字符串
*/
 public static String bytes2HexString(byte[] b) {
     String r = "";

     for (int i = 0; i < b.length; i++) {
         String hex = Integer.toHexString(b[i] & 0xFF);
         if (hex.length() == 1) {
             hex = '0' + hex;
         }
         r += hex.toUpperCase() + " ";
     }

     return r;
 }