使用Java實作單向加密(MD5,SHA-1)功能

package com.nelson.util;




import java.io.UnsupportedEncodingException;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import sun.misc.BASE64Encoder;




/** 

 * 此類別提供文字加密功能其加密之演算法可為MD5,SHA-1,SHA-256,SHA-384,SHA-512等.

 * 

 * 文件建立日期：2009/10/08

 * @author Nelson Chen

 * 

 */

public class Encryption {

 public Encryption(){

  

 }

 /** 

  * 此method提供加密之功能.

  * @param strPlanText 欲加密的文字.

  * @param strAlgorithm 欲使用加密的演算法:MD5,SHA-1,SHA-256,SHA-384,SHA-512.

  * @param strEncoding 文字之編碼:UTF-8,UTF-16,

  * @return 回傳一串加密後的文字.

  */

 public String Encrypt(String strPlanText,String strAlgorithm,String strEncoding){

  String strEncrypt = null;

  MessageDigest md = null;

  try{

   if(strEncoding==null || strEncoding.equals("")){

    strEncoding = "UTF-8";

   }

   

   if(strAlgorithm==null || strAlgorithm.equals("")){

    strAlgorithm = "MD5";

   }

   

   byte[] bstr = strPlanText.getBytes(strEncoding);

   md = MessageDigest.getInstance(strAlgorithm);

   md.update(bstr);

   strEncrypt = (new BASE64Encoder()).encode(md.digest());

  }catch(UnsupportedEncodingException ue){

   ue.printStackTrace();

   System.out.println(ue.getMessage());

   return null;

  }catch(NoSuchAlgorithmException na){

   na.printStackTrace();

   System.out.println(na.getMessage());

   return null;

  }

  return strEncrypt;

 }




 /**

  * 驗證加密功能是否正確!!

  */

 public static void main(String[] args){

  String chartCode = "UTF-8";

  String chartCode1 = "UTF-16";

  String inputStr = "Nelson";

  

  Encryption enc = new Encryption();

  

  System.out.println("input String:"+inputStr+",Encryption(SHA-1):"+enc.Encrypt(inputStr, "SHA-1",chartCode));  

  System.out.println("input String:"+inputStr+",Encryption(SHA-256):"+enc.Encrypt(inputStr, "SHA-256",chartCode));

  System.out.println("input String:"+inputStr+",Encryption(SHA-384):"+enc.Encrypt(inputStr, "SHA-384",chartCode));

  System.out.println("input String:"+inputStr+",Encryption(MD5):"+enc.Encrypt(inputStr, "MD5",chartCode));

  System.out.println("input String:"+inputStr+",Encryption(MD5):"+enc.Encrypt(inputStr, "MD5",chartCode1));

 }

}