加密解密类之二

/**
		 * 3DES 解密(byte[]).
		 */
		private static byte[] desDecrypt(SecretKey key, byte[] crypt){
			try {
				Cipher cipher = Cipher.getInstance("DESede");
				cipher.init(Cipher.DECRYPT_MODE, key);
				return cipher.doFinal(crypt);
			} catch (Exception e) {
			  e.printStackTrace();
			}
			return null;
		}
		
	   
	    /**
		 * 生成3DES密钥.
		 * @param key_byte seed key
		 * @return SecretKey Generated DES key
		 */
		private static SecretKey genDESKey(byte[] key_byte) {
			return new SecretKeySpec(key_byte, "DESede");
		}
		 /**
		  * 拼凑或者截取制定长度的字符串
		  * @param key
		  * @param max
		  * @return
		  */ 
		private static String getLimStr(String key,int max) {
			if(null==key){
				key = "";
			}
			int keyLength=key.getBytes().length;
			if(keyLength==max){
				return key;
			}
			//填充
			StringBuffer keyB = new StringBuffer(key);
			if(keyLength<max){
				for(int i=0;i<max-keyLength;i++){
					keyB.append("0");
				}
			}
			key = keyB.toString();
			String str = "";
			int i = 0;
			while (i <key.length() && (str+key.charAt(i)).getBytes().length<=max) {
				str += key.charAt(i);
				i++;
			}
			return str;
		}
		

	    /**
		 * byte数组转16进制字符串
		 * @param b
		 * @return
		 */
		private static  String byteArrayToHexString(byte b[]) {
			StringBuffer result = new StringBuffer();
			for (int i = 0; i < b.length; i++)
				result.append( byteToHexString(b[i]));
			return result.toString();
		}

		private  static  String byteToHexString(byte b) {
			int n = b;
			if (n < 0)
				n = 256 + n;
			int d1 = n / 16;
			int d2 = n % 16;
			return hexCode[d1] + hexCode[d2];
		}

	    static public String hexCode[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8",
				"9", "A", "B", "C", "D", "E", "F" };
	    
	    private static byte[] hexStringToBytes(String src){ 
	        byte[] ret = new byte[src.length()/2];
	        byte[] tmp = src.getBytes();
	        for(int i=0; i<src.length()/2; i++){
	          ret[i] = uniteBytes(tmp[i*2], tmp[i*2+1]);
	        }
	        return ret;
	     }
	    
	   /* 将两个ASCII字符合成一个字节；
	    * 如："EF"--> 0xEF
	    * @param src0 byte
	    * @param src1 byte
	    * @return byte
	    */
	  private static byte uniteBytes(byte src0, byte src1) {
	     byte _b0 = Byte.decode("0x" + new String(new byte[]{src0})).byteValue();
	     _b0 = (byte)(_b0 << 4);
	     byte _b1 = Byte.decode("0x" + new String(new byte[]{src1})).byteValue();
	     byte ret = (byte)(_b0 ^ _b1);
	     return ret;
	  }
	  
	  public static void main(String[] args) {
		
		  System.out.println(encrypt("wmba"));
		  System.out.println(decrypt("41666AFABEC36AC9"));
		  
	  }

加密实例：

result = SecurityUtil.encrypt(((EsbAdminUserInfo)getForm()).getPassWord());