code: public static String decrypt(String key,String data) {
      	if(data == null)
      		return null;
          try {
  	    	DESKeySpec dks = new DESKeySpec(key.getBytes());
  	    	SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
              //key的长度不能够小于8位字节
              Key secretKey = keyFactory.generateSecret(dks);
              Cipher cipher = Cipher.getInstance(ALGORITHM_DES);
              AlgorithmParameterSpec paramSpec = new IvParameterSpec(IV_PARAMS_BYTES);
              cipher.init(Cipher.DECRYPT_MODE, secretKey, paramSpec);
              return new String(cipher.doFinal(hex2byte(data.getBytes())));
          } catch (Exception e){
      		e.printStackTrace();
      		return data;
          }
      }
docs: DES算法，解密
  
  @param data 待解密字符串
  @param key  解密私钥，长度不能够小于8位
  @return 解密后的字节数组
  @throws Exception 异常