java 加密工具类

package com.tiancom.pas.util;

import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;



public class CryptoUtil {
    
     private static final byte[] DES_KEY= {21, 1, -110, 82, -32, -85, -128, -65};
    /**
     * 日志对象,参见org.apache.commons.logging.Log
     */
    private static Log log= LogFactory.getLog( CryptoUtil.class);
    
    /**
     * 不允许初始化
     */
    private CryptoUtil(){
    }
    
    /**
     * 数据加密，算法（DES）
     * @param data  要进行加密的数据
     * @return 加密后的数据
     */
    public static String encrypt( String data){
        String encryptedData= null;
        try {
            //DES算法要求有一个可信任的随机数源
            SecureRandom sr = new SecureRandom();
            DESKeySpec deskey = new DESKeySpec(DES_KEY);
 
            //创建一个密匙工厂，然后用它把DESKeySpec转换成一个SecretKey对象
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance( "DES" );
            SecretKey key = keyFactory.generateSecret( deskey);
 
            //加密对象
            Cipher cipher = Cipher.getInstance( "DES");
            cipher.init( Cipher.ENCRYPT_MODE, key, sr);
            
            //加密，并把字节数组编码成字符串
            encryptedData = new sun.misc.BASE64Encoder().encode( 
                                cipher.doFinal( data.getBytes()));
        } catch (Exception e) {
            log.error( "加密错误，错误信息：", e);
            throw new RuntimeException( "加密错误，错误信息：", e);
        }
        return encryptedData;
    }
    
    /**
     * 数据解密，算法（DES）
     * @param cryptData  加密数据
     * @return 解密后的数据
     */
    public static String decrypt( String cryptData){
        String decryptedData= null;
        try {
            //DES算法要求有一个可信任的随机数源
            SecureRandom sr = new SecureRandom();
            DESKeySpec deskey = new DESKeySpec(IConst.SYSTEM.DES_KEY);
 
            //创建一个密匙工厂，然后用它把DESKeySpec转换成一个SecretKey对象
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance( "DES" );
            SecretKey key = keyFactory.generateSecret( deskey);
 
            //解密对象
            Cipher cipher = Cipher.getInstance( "DES");
            cipher.init( Cipher.DECRYPT_MODE, key, sr);
            
            //把字符串解码为字节数组，并解密
            decryptedData = new String( cipher.doFinal( 
                       new sun.misc.BASE64Decoder().decodeBuffer(cryptData)));
        } catch (Exception e) {
            log.error( "解密错误，错误信息：", e);
            throw new RuntimeException( "解密错误，错误信息：", e);
        }
        return decryptedData;
    }
}