【JAVA】java实现DES加密算法

java实现DES加密算法：

package com.jiexun.ers.utils;

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

/**
 *
 * FileName：EncryptUtil.java
 *
 * Description：DES加密解密工具类
 *
 */
public class EncryptUtil {

    /**
     * 日志输出对象
     */
    public static final Log log = LogFactory.getLog(EncryptUtil.class);

    /**
     * 加密逻辑方法
     * @param message
     * @param key
     * @return
     * @throws Exception
     */
    private static byte[] encryptProcess(String message, String key) throws Exception {
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
        IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
        return cipher.doFinal(message.getBytes("UTF-8"));
    }

    /**
     * 解密逻辑方法
     * @param message
     * @param key
     * @return
     * @throws Exception
     */
    private static String decryptProcess(String message,String key) throws Exception {
            byte[] bytesrc =convertHexString(message);
            Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
            DESKeySpec desKeySpec = new DESKeySpec(key.getBytes("UTF-8"));
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
            IvParameterSpec iv = new IvParameterSpec(key.getBytes("UTF-8"));
            cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
            byte[] retByte = cipher.doFinal(bytesrc);
            return new String(retByte);
    }

    /**
     * 16进制数组数转化
     * @param ss
     * @return
     */
    private static byte[] convertHexString(String ss) throws Exception {
        byte digest[] = new byte[ss.length() / 2];
        for(int i = 0; i < digest.length; i++)
        {
        String byteString = ss.substring(2 * i, 2 * i + 2);
        int byteValue = Integer.parseInt(byteString, 16);
        digest[i] = (byte)byteValue;
        }
        return digest;
    }

    /**
     * 十六进制数转化
     * @param b
     * @return
     * @throws Exception
     */
    private static String toHexString(byte b[]) throws Exception {
        StringBuffer hexString = new StringBuffer();
        for (int i = 0; i < b.length; i++) {
            String plainText = Integer.toHexString(0xff & b[i]);
            if (plainText.length() < 2)
                plainText = "0" + plainText;
            hexString.append(plainText);
        }

        return hexString.toString();
    }

    /**
     * 加密方法
     */
    public static String encrypt(String message,String key){
        log.info("加密原串为：" + message);
        String enStr = null;
        try {
             String orignStr=java.net.URLEncoder.encode(message, "utf-8");
             enStr=toHexString(encryptProcess(orignStr, key));
        } catch (Exception e) {
            log.error("参数加密异常！", e);
        }
        return enStr;
    }


    /**
     * 解密方法
     */
    public static String decrypt(String message,String key){
        String decStr = null;
        try {
            log.debug("解密串：" + message);
            log.debug("解密KEY:" + key);
            decStr = java.net.URLDecoder.decode(decryptProcess(message,key), "utf-8") ;
            log.info("参数解密结果：" + decStr);
        }catch (Exception e) {
            log.error("参数解密异常！", e);
        }
        return decStr;
    }

    /**
     * 测试Main方法
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
         String key = "12345678"; //密码只能为8位
         String message ="sign=026ec875336739dee0132d39e8361f10";
         String enStr = encrypt(message,key);
         System.out.println("加密后:" + enStr);
         String decStr = decrypt(enStr,key);
         System.out.println("解密后:" + decStr);
    }
}