JAVA 实现DES MD5加密

package com.esailcar.finance.shenzhou.utils;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

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

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class SecretDigest {
        
        private final static String MD5="MD5";
        private final static String DES="DES";
        private final static String ENCODE="UTF-8";
        private final static String KEY="asdf1234";
        
        //MD5加密
        public static String encodeByMD5(String str) throws NoSuchAlgorithmException, UnsupportedEncodingException
        {
            MessageDigest md5=MessageDigest.getInstance(MD5);
            StringBuffer md5buffer=new StringBuffer();
            md5.update(str.getBytes("UTF-8"));
            byte[] md5bytes=md5.digest();
            String hexString=null;
            for(byte md5byte : md5bytes)
            {
                 hexString=Integer.toHexString(0xff&md5byte);
                if(hexString.length()==1)
                {
                    md5buffer.append("0").append(hexString);
                }
                else
                {
                    md5buffer.append(hexString);
                }
            }
            return md5buffer.toString();        
        }
        
        /**
         * DES加密
         * @param str
         * @return
         * @throws Exception
         */
        public static String encodeByDES(String str)throws Exception
        {
            byte[] data=str.getBytes(ENCODE);
            
            byte[] key=KEY.getBytes(ENCODE);
           
            SecureRandom sr = new SecureRandom();
            // 通过key创建DESKeySpec对象
            DESKeySpec dks = new DESKeySpec(key);
            
            // 创建SecretKeyFactory，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securekey初始化Cipher对象
            cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);
            
            //BASE64编码
            String message=new BASE64Encoder().encode(cipher.doFinal(data));
            return message;            
        }
        /**
         * DES解密
         * @param str
         * @return
         * @throws Exception
         */
        public static String decodeByDES(String str)throws Exception
        {
              if (str == null)
                    return null;
           //BASE64解码
           BASE64Decoder decoder = new BASE64Decoder();
            
            byte[] data=decoder.decodeBuffer(str);
            byte[] key=KEY.getBytes(ENCODE);
            SecureRandom sr = new SecureRandom();
            // 通过key创建DESKeySpec对象
            DESKeySpec dks = new DESKeySpec(key);

            // 创建SecretKeyFactory，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securekey初始化Cipher对象
            cipher.init(Cipher.DECRYPT_MODE, securekey, sr);
            return new String(cipher.doFinal(data), ENCODE);           
        }
}