Des加密类

需要导入Base64.jar包

import java.io.IOException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import Decoder.BASE64Decoder;
import Decoder.BASE64Encoder;

public class Des {

   private final static String DES = "DES";

   public static void main(String[] args) throws Exception {
      String data = "强大的黑马51期";
      String key = "wang!@#$%";
      System.err.println(encrypt(data, key));
//    System.err.println(decrypt(encrypt(data, key), key));
   }

   /**
    * Description 根据键值进行加密
    * @param data 
    * @param key  加密键byte数组
    * @return
    * @throws Exception
    */
   public static String encrypt(String data, String key) throws Exception {
      byte[] bt = encrypt(data.getBytes(), key.getBytes());
      String strs = new BASE64Encoder().encode(bt);
      return strs;
   }

   /**
    * Description 根据键值进行解密
    * @param data
    * @param key  加密键byte数组
    * @return
    * @throws IOException
    * @throws Exception
    */
   public static String decrypt(String data, String key) throws IOException, Exception {
      if (data == null)
         return null;
      BASE64Decoder decoder = new BASE64Decoder();
      byte[] buf = decoder.decodeBuffer(data);
      byte[] bt = decrypt(buf, key.getBytes());
      return new String(bt);
   }

   /**
    * Description 根据键值进行加密
    * @param data
    * @param key  加密键byte数组
    * @return
    * @throws Exception
    */
   private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
      // 生成一个可信任的随机数源
      SecureRandom sr = new SecureRandom();

      // 从原始密钥数据创建DESKeySpec对象
      DESKeySpec dks = new DESKeySpec(key);

      // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
      SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
      SecretKey securekey = keyFactory.generateSecret(dks);

      // Cipher对象实际完成加密操作
      Cipher cipher = Cipher.getInstance(DES);

      // 用密钥初始化Cipher对象
      cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

      return cipher.doFinal(data);
   }

   /**
    * Description 根据键值进行解密
    * @param data
    * @param key  加密键byte数组
    * @return
    * @throws Exception
    */
   private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
      // 生成一个可信任的随机数源
      SecureRandom sr = new SecureRandom();

      // 从原始密钥数据创建DESKeySpec对象
      DESKeySpec dks = new DESKeySpec(key);

      // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
      SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
      SecretKey securekey = keyFactory.generateSecret(dks);

      // Cipher对象实际完成解密操作
      Cipher cipher = Cipher.getInstance(DES);

      // 用密钥初始化Cipher对象
      cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

      return cipher.doFinal(data);
   }
}