流行的加密技术，MD5、DES、DESede、Blowfish

package com.xiucaike.common;
import java.security.MessageDigest;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import org.apache.log4j.Logger;
import org.junit.Test;
import sun.misc.BASE64Encoder;
/**


@author fnyexx



加密、类型转换工具

*/

@SuppressWarnings("restriction")

public class UtilCrpts {
private static final Logger logger = Logger.getLogger(UtilCrpts.class);
/** 定义 加密算法,可用 DES,DESede,Blowfish- 默认 DES*/

private String  Algorithm ="DES";
public String getAlgorithm() {

return Algorithm;

}
public void setAlgorithm(String algorithm) {

Algorithm = algorithm;

}
/** 生成密钥,随机生成
 * @return byte[] 返回生成的密钥
 */
 public String createSecretKey() {

 	KeyGenerator keygen = null;

 	try {
 		keygen = KeyGenerator.getInstance(Algorithm);
 	} catch (Exception e) {
 		logger.error("NoSuchAlgorithmException!");
 	}
 	SecretKey deskey = keygen.generateKey();

 	return byte2hex(deskey.getEncoded());
 }


 /**
  * 将指定的数据根据提供的密钥进行加密
  * @param input 需要加密的数据
  * @param key 密钥
  * @return byte[] 加密后的数据
  * @throws Exception
  */
 public byte[] encryptData(String input, String key) {

 	SecretKey deskey = new javax.crypto.spec.SecretKeySpec(stringToByte(key.replace(":", "")), Algorithm);
 	Cipher c1 = null;
 	byte[] cipherByte = null;

 	try {
 		c1 = Cipher.getInstance(Algorithm);
 		c1.init(Cipher.ENCRYPT_MODE, deskey);
 		cipherByte = c1.doFinal(input.getBytes());
 	} catch (Exception e) {
 		logger.error("error!");
 	} 

 	return cipherByte;
 } 

 /**
  * 将给定的已加密的数据通过指定的密钥进行解密
  * @param input 待解密的数据
  * @param key 密钥
  * @return byte[] 解密后的数据
  * @throws UnsupportedEncodingException 
  * @throws Exception
  */
 public String decryptData(String input, String key) {

 	SecretKey deskey = new javax.crypto.spec.SecretKeySpec(stringToByte(key.replace(":", "")), Algorithm);
 	Cipher c1 = null;
 	byte[] clearByte = null;
 	String decryptStr = null;

 	try {
 		c1 = Cipher.getInstance(Algorithm);
 		c1.init(Cipher.DECRYPT_MODE, deskey);
 		clearByte = c1.doFinal(stringToByte(input.replace(":", "")));
 		decryptStr = new String(clearByte,"utf-8");
 	} catch (Exception e) {
 		logger.error("error");
 	}

 	return decryptStr;
 } 

 /**
  *  对密码进行MD5加密(非对称加密，不能解密，适用于密码匹配)
  * @param :       String 原始密码
  * @return:       String 密码密文
  */
 public String MD5Encrypt(String pwd){

 	MessageDigest md = null;

 	try {
 		md = MessageDigest.getInstance("MD5");
 	} catch (Exception e) {
 		logger.error("NoSuchAlgorithmException!");
 	}
 	md.update(pwd.getBytes());
 	byte[] result = md.digest();
 	return byteToString(result);
 }

 /**
  * 字节码转换成16进制字符串
  * @param byte[]b 输入要转换的字节码
  * @return String 返回转换后的16进制字符串
  */
 public String byte2hex(byte[] b) {
 	String hs = "";
 	String stmp = "";
 	for (int n = 0; n < b.length; n++) {
 		stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
 		if (stmp.length() == 1)
 			hs = hs + "0" + stmp;
 		else
 			hs = hs + stmp;
 		if (n < b.length - 1)
 			hs = hs + ":";
 	}
 	return hs.toUpperCase();
 }

 /**
  * 16进制字符串转换为byte数组 "1212"={12,12}
  * @param strIn
  *            需要转换的字符串
  * @return 转换后的byte数组
  * @throws IllegalArgumentException
  */
 public byte[] stringToByte(String hex)
 		throws IllegalArgumentException
 {

 	if (hex.length() % 2 != 0)
 	{
 		throw new IllegalArgumentException();
 	}

 	char[] arr = hex.toCharArray();
 	byte[] b = new byte[hex.length() / 2];

 	for (int i = 0, j = 0, l = hex.length(); i < l; i++, j++)
 	{
 		String swap = "" + arr[i++] + arr[i];
 		int byteint = Integer.parseInt(swap, 16) & 0xFF;
 		b[j] = new Integer(byteint).byteValue();
 	}
 	return b;
 }	

 /**
  *  二进制 byte[] 转字符串   {12,12}="1212"
  * @param :       byte[]
  * @return:       String
  * @throws        AppException
  */
 public String byteToString(byte[] b) { 
 	String hs = "";
 	String stmp = "";
 	for (int n = 0; n < b.length; n++) {
 		stmp = (Integer.toHexString(b[n] & 0XFF));
 		if (stmp.length() == 1) {
 			hs = hs + "0" + stmp;
 		} else {
 			hs = hs + stmp;
 		}
 		if (n < (b.length - 1)) {
 			hs = hs + "";
 		}
 	}
 	return hs;
 }
 /**
  * int类型转换为byte[]类型
  * @param input 待转换的int值
  * @return byte[]
  */
 public byte[] intTobyte(int input) {
 	byte[] output = new byte[4];
 	output[0] = (byte) (input & 0xff);
 	output[1] = (byte) ((input >> 8) & 0xff);
 	output[2] = (byte) ((input >> 16) & 0xff);
 	output[3] = (byte) (input >>> 24);
 	return output;
 }

 /**
  * byte[]类型转换为int类型
  * @param input 待转换的byte值
  * @return int
  */
 public int byteToint(byte[] input) {
 	int output = 0;
 	if (input.length != 4) {

 		logger.error("error!");
 	}
 	output = (input[0] & 0xff) | ((input[1] << 8) & 0xff00)
 			| ((input[2] << 24) >>> 8) | (input[3] << 24);
 	return output;
 }


 /**
  * 字节数组使用Base64进行编码
  * @param value 待编码的字节数组
  * @return 使用Base64进行编码的字节数组
  */
 public String encdoeStrUsingBase64(byte[] value){

 	String encodeTxt = "";
     if( value!=null && value.length>0 ){
     	encodeTxt= new BASE64Encoder().encode(value);
 	}

     return encodeTxt;
 } 

 //DES测试   DESede,Blowfish操作一样
 @Test
 public void test(){

 	String key = createSecretKey();
 	String text = "123asdf んぁ”●☆我是好人/.,";
 	String crpt  = byte2hex(encryptData(text , key));

 	System.out.println("生成KEY：" + key);
 	System.out.println("末加密原文 ：" + text);

 	System.out.println("MD5加密后密文：" + MD5Encrypt(text));
 	System.out.println("DES加密后密文：" + crpt);

 	System.out.println("DES解密后的原文：" + decryptData(crpt, key));

 }
​


}