使用DES加密解密的工具类

一个工具类，很常用，不做深入研究了，那来可直接用

 

DesUtil.java

 

 package lsy;

 import java.security.Key;
 import java.security.SecureRandom;

 import javax.crypto.Cipher;
 import javax.crypto.KeyGenerator;
 import javax.crypto.SecretKey;

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

 public class DesUtil {

     /**
      * @param args
      */
     public static void main(String[] args) {
         //以下是加密方法algorithm="AES"的测试

         System.out.println(DesUtil.getInstance("lushuaiyin").getEnCodeString("hello"));
         //输出  LDewGAZkmWHeYFjBz56ylw==
         //将上面的密文解密：
         System.out.println(DesUtil.getInstance("lushuaiyin").getDecodeString("LDewGAZkmWHeYFjBz56ylw=="));
         //输出   hello

         //改变密钥测试
         System.out.println(DesUtil.getInstance("suolong").getEnCodeString("hello"));
         //输出  /RLowOJ+Fr3KdMcdJeNatg==
         System.out.println(DesUtil.getInstance("suolong").getDecodeString("/RLowOJ+Fr3KdMcdJeNatg=="));
         //输出   hello

         //如果使用不正确的密钥解密，将会：
         System.out.println(DesUtil.getInstance("suolong").getDecodeString("LDewGAZkmWHeYFjBz56ylw=="));

     }

     private  SecretKey key=null;//密钥

     //定义 加密算法,可用 DES,DESede,Blowfish,AES
     //不同的加密方式结果会不同
     private  static String algorithm="AES";

     private  static DesUtil desUtil=null;


     public DesUtil(){}

     public static DesUtil getInstance(String strKey){
         desUtil=new DesUtil();
         desUtil.createKey(strKey);
         return desUtil;
     }
     /**
      * algorithm 算法
      * @param strKey
      */
     public void createKey(String strKey){

         try{
             KeyGenerator kg=KeyGenerator.getInstance(DesUtil.algorithm);
             byte[] bt=strKey.getBytes("UTF-8");
             SecureRandom sr=new SecureRandom(bt);
             kg.init(sr);
             this.setKey(kg.generateKey());
         }catch(Exception e){

         }
     }
     /**
      * 加密方法，返回密文
      * cipher 密码
      * @param dataStr
      */
     public  String getEnCodeString(String dataStr){
         byte[] miwen=null;//密文
         byte[] mingwen=null;//明文
         Cipher cipher;
         String result="";//密文字符串
         try{
             mingwen=dataStr.getBytes("UTF-8");
             cipher=Cipher.getInstance(DesUtil.algorithm);
             cipher.init(Cipher.ENCRYPT_MODE, this.getKey());
             miwen=cipher.doFinal(mingwen);

             BASE64Encoder base64en = new BASE64Encoder();
             result=base64en.encodeBuffer(miwen);//或者可以用下面的方法得到密文，结果是不一样的，都可以正常解密
 //          result=byte2hex(miwen);//密文结果类似2C:37:B0:18:06:64:99:61:DE:60:58:C1:CF:9E:B2:97
         }catch(Exception e){
             e.printStackTrace();
         }
         return result;
     }

     /**
      * 解密方法，返回明文
      * @param codeStr
      * @return
      */
     public  String getDecodeString(String codeStr){
         BASE64Decoder base64De = new BASE64Decoder();
         byte[] miwen=null;
         byte[] mingwen=null;
         String resultData="";//返回的明文
         Cipher cipher;
         try{
             miwen=base64De.decodeBuffer(codeStr);
             cipher=Cipher.getInstance(DesUtil.algorithm);
             cipher.init(Cipher.DECRYPT_MODE, this.getKey());

             mingwen=cipher.doFinal(miwen);
             resultData = new String(mingwen,"UTF-8");
         }catch(Exception e){
             return "密钥不正确或其他原因导致异常，无法解密！";
         }

         return resultData;
     }

      //二行制转字符串
     public String byte2hex(byte[] b) {
         String hs = "";
         String stmp = "";
         for (int n = 0; n < b.length; n++) {
             stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
             if (stmp.length() == 1)
                 hs = hs + "0" + stmp;
             else
                 hs = hs + stmp;
             if (n < b.length - 1)
                 hs = hs + ":";
         }
         return hs.toUpperCase();
     }



     public  SecretKey getKey() {
         return key;
     }
     public  void setKey(SecretKey key) {
         this.key = key;
     }
     public static String getAlgorithm() {
         return algorithm;
     }
     public static void setAlgorithm(String algorithm) {
         algorithm = algorithm;
     }


 }

 

打印：

LDewGAZkmWHeYFjBz56ylw==

hello
/RLowOJ+Fr3KdMcdJeNatg==

hello
密钥不正确或其他原因导致异常，无法解密！