/*

 * @(#) EncrypAES.java

 */

import java.security.InvalidKeyException;

import java.security.NoSuchAlgorithmException;

import java.security.spec.InvalidKeySpecException;

import javax.crypto.BadPaddingException;

import javax.crypto.Cipher;

import javax.crypto.IllegalBlockSizeException;

import javax.crypto.NoSuchPaddingException;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

/**

 * 功能描述: 这里注意二进制转十六进制，十六进制转二进制的必要性                            

 * @version 2.4.0

 * @Copyright (c) 2002-2013 All rights reserved.

 * @create 2012-12-13 上午11:11:02

 **/

public class EncrypDes {

    private static final String key="travelSkyGuiParameter";

    private SecretKeyFactory keyFactory = null;

    // 生成加密密钥

    private DESKeySpec keySpec = null;

    private SecretKey secretKey = null;

    private Cipher cipher = null;

    public EncrypDes() throws InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException{

        //KeySpec组成加密密钥的密钥内容的（透明）规范

        keySpec = new DESKeySpec(key.getBytes());

        keyFactory = SecretKeyFactory.getInstance("DES");

        // key的长度不能够小于8位字节

        secretKey = keyFactory.generateSecret(keySpec);

        cipher = Cipher.getInstance("DES");

    }

    public String Encrytor(String str) throws InvalidKeyException, NoSuchAlgorithmException,

        InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException {

        // 根据密钥，对Cipher对象进行初始化，ENCRYPT_MODE表示加密模式

        cipher.init(Cipher.ENCRYPT_MODE, secretKey);

        byte[] src = str.getBytes();

        // 加密，结果保存进cipherByte

        byte[] encryByte = cipher.doFinal(src);

        String encryStr = parseByte2HexStr(encryByte);

        return encryStr;

    }

    public String Decryptor(String str) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

        // 根据密钥，对Cipher对象进行初始化，DECRYPT_MODE表示加密模式

        byte[] encryByte = parseHexStr2Byte(str);

        cipher.init(Cipher.DECRYPT_MODE, secretKey);

        return new String(cipher.doFinal(encryByte));

        /*byte[] decryByte = cipher.doFinal(encryByte);

        return parseByte2HexStr(decryByte);*/

    }  

    /**将二进制转换成16进制

     * @param buf

     * @return

     */

    public static String parseByte2HexStr(byte buf[]) {

            StringBuffer sb = new StringBuffer();

            for (int i = 0; i < buf.length; i++) {

                    String hex = Integer.toHexString(buf[i] & 0xFF);

                    if (hex.length() == 1) {

                            hex = '0' + hex;

                    }

                    sb.append(hex.toUpperCase());

            }

            return sb.toString();

    }

    /**将16进制转换为二进制

     * @param hexStr

     * @return

     */

    public static byte[] parseHexStr2Byte(String hexStr) {

            if (hexStr.length() < 1)

                    return null;

            byte[] result = new byte[hexStr.length()/2];

            for (int i = 0;i< hexStr.length()/2; i++) {

                    int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);

                    int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);

                    result[i] = (byte) (high * 16 + low);

            }

            return result;

    }      

    public static void main(String[] args) throws Exception {

        EncrypDes des = new EncrypDes();

        EncrypDes des2 = new EncrypDes();

        String msg = "test_1212_我爱你——@#￥%……&";

        String encontent = des.Encrytor(msg);

        String encontent2 = des2.Encrytor(msg);

        String decontent = des.Decryptor(encontent);

        String decontent2 = des2.Decryptor(encontent);

        System.out.println("明文是:" + msg);

        System.out.println("加密后:" + encontent);

        System.out.println("解密后:" +decontent);

        System.out.println("加密后:" + encontent2);

        System.out.println("解密后:" + decontent2);

        System.out.println("is equals:" + encontent.equals(encontent2));

    }

}