一般加密和解密工具类

package com.snail.util;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

import com.d1xn.common.base.SystemConfig;
import com.d1xn.common.log.Log;


/**
 * 一般加密解密工具<br>
 * DESede/DES/BlowFish<br>
 * DES的密钥(key)长度是为8个字节,加密解密的速度是最快的<br>
 * DESede的密钥(key)长度是24个字节<br>
 * BlowFish的密钥(key)是可变的 加密最快，强度最高,密钥长度范围(1<=key<=16)<br>
 * 
 * @author penghuaiyi
 * @version 1.0
 */
public class SecretCodeUtil {
	public final static String DES = "DES";
	public final static String DESEDE = "DESede";
	public final static String BLOWFISH = "BlowFish";
	public final static String MD5 = "MD5";

	/**
	 * md5加密
	 * 
	 * @param plainText
	 * @return 加密后的大写字符串
	 */
	public static String getMD5ofStr(String plainText) {
		try {
			return getMD5ofStr(string2Bytes(plainText));
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * md5加密
	 * 
	 * @param str
	 * @return 加密后的大写字符串
	 */
	public static String getMD5ofStr(byte str[]) {
		try {
			MessageDigest md = MessageDigest.getInstance(MD5);
			md.update(str);
			byte b[] = md.digest();
			return bytes2HexString(b);

		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 字符串加密
	 * 
	 * @param data
	 *            字符串数据
	 * @param key
	 *            密钥
	 * @param name
	 *            算法名称
	 * @throws Exception
	 */
	public static String encrypt(String data, String key, String name) {
		try {
			return bytes2HexString(encrypt(data.getBytes(), string2Bytes(key), name));
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 字符串加密
	 * 
	 * @param data
	 *            字符串数据
	 * @param key
	 *            密钥
	 * @param name
	 *            算法名称
	 * @throws Exception
	 */
	public static String encrypt(String data, byte[] key, String name) {
		try {
			return bytes2HexString(encrypt(data.getBytes(), key, name));
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 字符串解密
	 * 
	 * @param data
	 *            字符串加密数据
	 * @param key
	 *            密钥
	 * @param name
	 *            算法名称
	 * @return
	 * @throws Exception
	 */
	public static String decrypt(String data, String key, String name) {
		try {
			return new String(decrypt(hex2byte(data.getBytes()), string2Bytes(key), name));
		} catch (Exception e) {
			Log.error(SecretCodeUtil.class, e, "data:" + data);
		}
		return null;
	}

	/**
	 * 字符串解密
	 * 
	 * @param data
	 *            字符串加密数据
	 * @param key
	 *            密钥
	 * @param name
	 *            算法名称
	 * @return
	 * @throws Exception
	 */
	public static String decrypt(String data, byte[] key, String name) {
		try {
			return new String(decrypt(hex2byte(data.getBytes()), key, name));
		} catch (Exception e) {

		}
		return null;
	}

	/**
	 * 对数据源进行加密
	 * 
	 * @param src
	 *            数据源
	 * @param key
	 *            密钥
	 * @param name
	 *            算法的名称
	 * @return 返回加密后的数据
	 * @throws Exception
	 */
	private static byte[] encrypt(byte[] src, byte[] key, String name) throws Exception {

		SecretKeySpec securekey = new SecretKeySpec(key, name);
		// Cipher对象实际完成加密操作
		Cipher cipher = Cipher.getInstance(name);
		// 用密匙初始化Cipher对象
		cipher.init(Cipher.ENCRYPT_MODE, securekey);
		// 现在，获取数据并加密
		// 正式执行加密操作
		return cipher.doFinal(src);
	}

	/**
	 * 对加密的数据源进行解密
	 * 
	 * @param src
	 *            数据源
	 * @param key
	 *            密钥
	 * @param name
	 *            算法的名称
	 * @return 返回解密后的原始数据
	 * @throws Exception
	 */
	private static byte[] decrypt(byte[] src, byte[] key, String name) throws Exception {

		SecretKeySpec securekey = new SecretKeySpec(key, name);
		// Cipher对象实际完成解密操作
		Cipher cipher = Cipher.getInstance(name);
		// 用密匙初始化Cipher对象
		cipher.init(Cipher.DECRYPT_MODE, securekey);
		// 现在，获取数据并解密
		// 正式执行解密操作
		return cipher.doFinal(src);
	}

	/**
	 * 二行制转字符串
	 * 
	 * @param b
	 * @return
	 */
	private static String bytes2HexString(byte[] bytes) {
		String hs = null;
		if (bytes != null) {
			final int size = bytes.length;
			if (size > 0) {
				StringBuilder sb = new StringBuilder();
				for (int i = 0; i < size; i++) {
					String tmp = (java.lang.Integer.toHexString(bytes[i] & 0XFF));
					if (tmp.length() == 1) {
						sb.append("0" + tmp);
					} else {
						sb.append(tmp);
					}
				}
				hs = sb.toString().toUpperCase();
			}
		}
		return hs;
	}



	/**
	 * 把字符串转化成 Unicode Bytes.
	 * 
	 * @param s
	 *            String
	 * @return byte[]
	 */
	private static byte[] string2Bytes(String s) {
		byte[] bytes = null;
		if (s != null) {
			try {
				bytes = s.getBytes(SystemConfig.DEFAULT_ENCODING);
			} catch (UnsupportedEncodingException e) {
				e.printStackTrace();
			}
		}
		return bytes;
	}



	/**
	 * 结字节进行转换
	 * 
	 * @param b
	 * @return
	 */
	private static byte[] hex2byte(byte[] b) {
		if ((b.length % 2) != 0) {
			return null;
		}
		byte[] b2 = new byte[b.length / 2];
		for (int n = 0; n < b.length; n += 2) {
			String item = new String(b, n, 2);
			b2[n / 2] = (byte) Integer.parseInt(item, 16);
		}
		return b2;
	}
	
	public static void main(String[] args){
		//DES加密与解密
		String key = "snail001";
		String encrypt = SecretCodeUtil.encrypt("fuckyou2013", key, SecretCodeUtil.DES); //加密
		System.out.println(encrypt);
		String decrypt = SecretCodeUtil.decrypt(encrypt, key,  SecretCodeUtil.DES);//解密
		System.out.println(decrypt);
		
		//MD5加密，不可逆的
		String md5 = SecretCodeUtil.getMD5ofStr("fuckyou2013");
		System.out.println(md5);
	}
	
}