java使用des加密解密示例分享

import java.security.key;
import java.security.securerandom;
import java.security.spec.algorithmparameterspec;

import javax.crypto.cipher;
import javax.crypto.secretkeyfactory;
import javax.crypto.spec.deskeyspec;
import javax.crypto.spec.ivparameterspec;

import org.apache.commons.logging.log;
import org.apache.commons.logging.logfactory;

public class des
{
    public static final string algorithm_des = "des/cbc/pkcs5padding";
    private static log log = logfactory.getlog(des.class);

    /**
     * des算法，加密
     *
     * @param data 待加密字符串
     * @param key  加密私钥，长度不能够小于8位
     * @return 加密后的字节数组，一般结合base64编码使用
     * @throws cryptexception 异常
     */
    public static string encode(string key,string data) throws exception
    {
        return encode(key, data.getbytes());
    }
    /**
     * des算法，加密
     *
     * @param data 待加密字符串
     * @param key  加密私钥，长度不能够小于8位
     * @return 加密后的字节数组，一般结合base64编码使用
     * @throws cryptexception 异常
     */
    public static string encode(string key,byte[] data) throws exception
    {
        try
        {
      deskeyspec dks = new deskeyspec(key.getbytes());

      secretkeyfactory keyfactory = secretkeyfactory.getinstance("des");
            //key的长度不能够小于8位字节
            key secretkey = keyfactory.generatesecret(dks);
            cipher cipher = cipher.getinstance(algorithm_des);
            ivparameterspec iv = new ivparameterspec("********".getbytes());
            algorithmparameterspec paramspec = iv;
            cipher.init(cipher.encrypt_mode, secretkey,paramspec);

            byte[] bytes = cipher.dofinal(data);
            return base64.encode(bytes);
        } catch (exception e)
        {
            throw new exception(e);
        }
    }

    /**
     * des算法，解密
     *
     * @param data 待解密字符串
     * @param key  解密私钥，长度不能够小于8位
     * @return 解密后的字节数组
     * @throws exception 异常
     */
    public static byte[] decode(string key,byte[] data) throws exception
    {
        try
        {
         securerandom sr = new securerandom();
      deskeyspec dks = new deskeyspec(key.getbytes());
      secretkeyfactory keyfactory = secretkeyfactory.getinstance("des");
            //key的长度不能够小于8位字节
            key secretkey = keyfactory.generatesecret(dks);
            cipher cipher = cipher.getinstance(algorithm_des);
            ivparameterspec iv = new ivparameterspec("********".getbytes());
            algorithmparameterspec paramspec = iv;
            cipher.init(cipher.decrypt_mode, secretkey,paramspec);
            return cipher.dofinal(data);
        } catch (exception e)
        {
//         e.printstacktrace();
            throw new exception(e);
        }
    }

    /**
     * 获取编码后的值
     * @param key
     * @param data
     * @return
     * @throws exception
     * @throws exception
     */
    public static string decodevalue(string key,string data) throws exception
    {
     byte[] datas;
     string value = null;

     datas = decode(key, base64.decode(data));

  value = new string(datas);
  if (value.equals("")){
   throw new exception();
  }
     return value;
    }
}