加密和解密

package com.lot.common.util;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 *
 * <p>
 * Title:
 * </p>
 * <p>
 * Description: 采用AES负责字符串的加密与解密
 * </p>
 * <p>
 * Copyright: Copyright (c) 2011 版权
 * </p>
 * <p>
 * Company:
 * </p>
 *
 * @author kevin
 * @version V1.0
 * @date 2011-5-27上午10:57:33
 */
public class SecUtil {

 private static final Log logger = LogFactory.getLog(SecUtil.class);
 /**
  * key 可自定义
  */
 private static byte[] keybytes = { 0x31, 0x32, 0x33, 0x34, 0x35, 0x50,
   0x37, 0x38, 0x39, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46 };

 public static void main(String[] args) throws Exception {
  
  BufferedReader reader;
  String input;
  int i = 0;
  try {
   String st = "";
   System.out.println("AES加密与解密操作:");
   System.out.println("\"E\":加密 \t\"D\":解密\t\t\"Q\":退出");
   do{
    if("".equals(st)) {
     System.out.println("请输入操作代码:");
    }
    reader = new BufferedReader(new InputStreamReader(System.in));
    st = reader.readLine();
    if("E".equalsIgnoreCase(st)) {
     System.out.println("请输入待加密字符串:");
     st = reader.readLine();
     if(!"".equals(st.trim())) {
      System.out.println("加密前:" + st.trim());
      System.out.println("加密后:" + encrypt(st.trim()) + "\n\n");
     }
     st = "";
    }else if("D".equalsIgnoreCase(st)) {
     System.out.println("请输入待解密字符串:");
     st = reader.readLine();
     if(!"".equals(st.trim())) {
      System.out.println("解密前:" + st.trim());
      System.out.println("解密后:" + decrypt(st.trim()) + "\n\n");
     }
     st = "";
    }
   } while(!st.equalsIgnoreCase("Q"));
  } catch (Exception e) {
   logger.error(StringHandleUtils.getExceptionInfo(e));
  }
 }

 /**
  *
  * @author: kevin
  * @Title encrypt
  * @Time: 2011-5-27上午10:57:56
  * @Description: 加密
  * @return: String
  * @throws:
  * @param value
  * @return
  */
 public static String encrypt(String value) {

  String s = null;

  int mode = Cipher.ENCRYPT_MODE;

  try {
   Cipher cipher = initCipher(mode);

   byte[] outBytes = cipher.doFinal(value.getBytes());

   s = String.valueOf(Hex.encodeHex(outBytes));
  } catch (Exception e) {
   logger.error(StringHandleUtils.getExceptionInfo(e));
  }

  return s;
 }

 /**
  *
  * @author: kevin
  * @Title decrypt
  * @Time: 2011-5-27上午10:58:09
  * @Description: 解密
  * @return: String
  * @throws:
  * @param value
  * @return
  */
 public static String decrypt(String value) {
  String s = null;

  int mode = Cipher.DECRYPT_MODE;

  try {
   Cipher cipher = initCipher(mode);

   byte[] outBytes = cipher
     .doFinal(Hex.decodeHex(value.toCharArray()));

   s = new String(outBytes);
  } catch (Exception e) {
   logger.error(StringHandleUtils.getExceptionInfo(e));
  }

  return s;
 }

 /**
  *
  * @author: kevin
  * @Title initCipher
  * @Time: 2011-5-27上午10:58:47
  * @Description: 初始化密码
  * @return: Cipher
  * @throws:
  * @param mode
  * @return
  * @throws NoSuchAlgorithmException
  * @throws NoSuchPaddingException
  * @throws InvalidKeyException
  */
 private static Cipher initCipher(int mode) throws NoSuchAlgorithmException,
   NoSuchPaddingException, InvalidKeyException {
  Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
  Key key = new SecretKeySpec(keybytes, "AES");
  cipher.init(mode, key);
  return cipher;
 }
}