package util.Encrypt;
 
import java.io.IOException;
import java.security.SecureRandom;
 
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import org.apache.commons.codec.binary.*;
 
public class DES {
 
 private final static String DES = "DES";
 
 
 //生成一个DES密钥
 public static String getKey(){
 try {
 KeyGenerator keyGenerator = KeyGenerator.getInstance("DES");
			keyGenerator.init(56);
			// 生成一个Key
			SecretKey generateKey = keyGenerator.generateKey();
			// 转变为字节数组
			byte[] encoded = generateKey.getEncoded();
			// 生成密钥字符串
 String encodeHexString = Hex.encodeHexString(encoded);
			return encodeHexString;
 } catch (Exception e) {
 e.printStackTrace();
 return null;
 } 
 }
 
 /**
 * 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 Base64(true).encodeToString(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;
 byte[] buf = new Base64(true).decode(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
 */
 public 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
 */
 public 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);
 }
}