3DES加密、解密工具类

package com.w;

import java.security.Key;
import java.security.Security;
import java.util.logging.Logger;

import javax.crypto.Cipher;

public class ThreeDesUtil
{
// 密钥的默认键
private static String defaultKey = "key";

// 加密密码功能对象
private Cipher encryptCipher = null;

// 解密密码功能对象
private Cipher decryptCipher = null;

private Logger logger = Logger.getLogger("decrypt");

/**
* 默认构造函数
*/
public ThreeDesUtil()
{
this(defaultKey);

}

/**
* 使用指定的密钥键
* @param strKey 密钥键
*/
public ThreeDesUtil(String strKey)
{
Security.addProvider(new com.sun.crypto.provider.SunJCE());
Key key = getKey(strKey.getBytes());
try
{
encryptCipher = Cipher.getInstance("DES");
encryptCipher.init(Cipher.ENCRYPT_MODE, key);

decryptCipher = Cipher.getInstance("DES");
decryptCipher.init(Cipher.DECRYPT_MODE, key);
}
catch (Exception e)
{
logger.warning(e.getMessage());
}
}

/**
* 加密指定的字符串
* @param str 需要加密的字符串
* @return 加密后的字符串
*/
public String encrypt(String str)
{
byte[] byteMi = null;
byte[] byteMing = null;

// 加密后的字符串
String strEncrypt = "";

try
{
byteMing = str.getBytes("UTF8");
byteMi = encryptCipher.doFinal(byteMing);
strEncrypt = Base64.encode(byteMi);
}
catch (Exception e)
{
logger.warning(e.getMessage());
}
finally
{
byteMing = null;
byteMi = null;
}

return strEncrypt;
}

/**
* 根据指定的加密字符串，获取解密后的明文
* @param strMi 加密的字符串
* @return 返回解密后的明文
*/
public String decrypt(String strMi)
{
byte[] byteMing = null;
byte[] byteMi = null;
String strMing = "";
try
{
byteMi = Base64.decode(strMi);
byteMing = decryptCipher.doFinal(byteMi);
strMing = new String(byteMing, "UTF8");
}
catch (Exception e)
{
logger.warning(e.getMessage());
}
finally
{
byteMing = null;
byteMi = null;
}

return strMing;
}

/**
* 根据指定的字节数组，构造一个密钥
* @param arrBTmp 字节数组
* @return 返回生成后的密钥
*/
private Key getKey(byte[] array)
{
// 创建一个空的8位字节数组
byte[] arrayTemp = new byte[8];
int length = array.length;

// 长度是否大于8
if (length > 8)
{
System.arraycopy(array, 0, arrayTemp, 0, 8);
}
else
{
System.arraycopy(array, 0, arrayTemp, 0, length);
}

// 生成密钥
Key key = new javax.crypto.spec.SecretKeySpec(arrayTemp, "DES");

return key;
}

}