字符串加密解密类

import javax.crypto.*;

import javax.crypto.spec.*;

import java.security.*;



public class EncryptData {



    DESedeKeySpec spec;

    SecretKeyFactory keyFactory;

    SecretKey theKey;

    Cipher cipher;

    IvParameterSpec IvParameters;



    public EncryptData() {

       byte[] encryptKey;

       try {

           // 检测是否有 TripleDES 加密的供应程序

           // 如无，明确地安装SunJCE 供应程序

           try {

              Cipher c = Cipher.getInstance("DESede");

           } catch (Exception e) {

              System.err.println("Installling SunJCE provider.");

              Provider sunjce = new com.sun.crypto.provider.SunJCE();

              Security.addProvider(sunjce);

           }

           // 创建一个密钥

           encryptKey = "This is a test DESede Key".getBytes();



           // 为上一密钥创建一个指定的 DESSede key

           spec = new DESedeKeySpec(encryptKey);



           // 得到 DESSede keys

           keyFactory = SecretKeyFactory.getInstance("DESede");



           // 生成一个 DESede 密钥对象

           theKey = keyFactory.generateSecret(spec);



           // 创建一个 DESede 密码

           cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");



           // 为 CBC 模式创建一个用于初始化的 vector 对象

           IvParameters = new IvParameterSpec(new byte[] { 12, 34, 56, 78, 90, 87, 65, 43 });

       } catch (Exception exc) {

           // 记录加密或解密操作错误

       }

    }



    private String encrypt(String password) {

       String encrypted_password = null;

       byte[] encrypted_pwd = null;



       try {

           // 以加密模式初始化密钥

           cipher.init(Cipher.ENCRYPT_MODE, theKey, IvParameters);



           // 加密前的密码（旧）

           byte[] plainttext = password.getBytes();



           // 加密密码

           encrypted_pwd = cipher.doFinal(plainttext);



           // 转成字符串，得到加密后的密码（新）

           encrypted_password = new String(encrypted_pwd);

       } catch (Exception ex) {

           // 记录加密错误

       }



       StringBuffer tempString = new StringBuffer();

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

           tempString.append(encrypted_pwd[i] + ",");

       }



       String aa = new String(tempString);

       return aa;

    }



    private String decrypt(String spassword) {

       String[] ss = spassword.split(",");

       byte[] password = new byte[ss.length];

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

           password[i] = (byte) (new Integer(ss[i]).intValue());

       }

       String decrypted_password = null;

       try {

           // 以解密模式初始化密钥

           cipher.init(Cipher.DECRYPT_MODE, theKey, IvParameters);



           // 构造解密前的密码

           byte[] decryptedPassword = password;



           // 解密密码

           byte[] decrypted_pwd = cipher.doFinal(decryptedPassword);

           // 得到结果

           decrypted_password = new String(decrypted_pwd);

       } catch (Exception ex) {

           // 记录解密错误

       }

       return decrypted_password;

    }



    /**

     * 加密算法

     * @param password   未加密的密码

     * @return           加密后的密码

     */

    public static String s_encrypt(String password) {

       String encrypted_pwd = null;

       EncryptData encryptData = new EncryptData();

       encrypted_pwd = encryptData.encrypt(password);

       return encrypted_pwd;

    }



    /**

     * 解密算法

     * @param password   加过密的密码

     * @return           解密后的密码

     */

    public static String b_decrypt(String password) {

       String decrypted_password = null;

       EncryptData encryptData = new EncryptData();

       decrypted_password = encryptData.decrypt(password);

       return decrypted_password;

    }



}