javaMD5加密及登录验证（备忘）

MD5类

package view.login.composer;
 import java.security.MessageDigest;  
   
 /**  
  * 对密码进行加密和验证的类 
  */  
 public class CipherUtil{  
       
     private final static String[] hexDigits = {"0", "1", "2", "3", "4",  
         "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};  
       
     /** * 把inputString加密     */  
     public static String generatePassword(String inputString){  
         return encodeByMD5(inputString);  
     }  
       
      
     public static boolean validatePassword(String password, String inputString){  
         if(password.equals(encodeByMD5(inputString))){  
             return true;  
         } else{  
             return false;  
         }  
     }  
     public static String returnEncodeByMde(String originString){
    	 return encodeByMD5(originString);
     }
     /**  对字符串进行MD5加密     */  
     private static String encodeByMD5(String originString){  
         if (originString != null){  
             try{  
                 MessageDigest md = MessageDigest.getInstance("MD5");  
                 //使用指定的字节数组对摘要进行最后更新，然后完成摘要计算  
                 byte[] results = md.digest(originString.getBytes());  
                 //将得到的字节数组变成字符串返回  
                 String resultString = byteArrayToHexString(results);  
                 String pass =  resultString.toUpperCase();  
                 return pass;
             } catch(Exception ex){  
                 ex.printStackTrace();  
             }  
         }  
         return null;  
     }  
       
   
     private static String byteArrayToHexString(byte[] b){  
         StringBuffer resultSb = new StringBuffer();  
         for (int i = 0; i < b.length; i++){  
             resultSb.append(byteToHexString(b[i]));  
         }  
         return resultSb.toString();  
     }  
       
     /** 将一个字节转化成十六进制形式的字符串     */  
     private static String byteToHexString(byte b){  
         int n = b;  
         if (n < 0)  
             n = 256 + n;  
         int d1 = n / 16;  
         int d2 = n % 16;  
         return hexDigits[d1] + hexDigits[d2];  
     }  
     
     public static void main(String[] args){
    	          String pwd1="123";  
    	          String pwd2="";  
    	          CipherUtil cipher = new CipherUtil();  
    	          System.out.println("未加密的密码:"+pwd1);  
    	          //将123加密  
    	          pwd2 = cipher.generatePassword(pwd1);  
    	          System.out.println("加密后的密码:"+pwd2);  
    	            
    	          System.out.print("验证密码是否下确:");  
    	          if(cipher.validatePassword(pwd2, pwd1)) {  
    	              System.out.println("正确");  
    	          }  
    	          else {  
    	              System.out.println("错误");  
    	          }  
     }
 }  

加密

login.setPassword(CipherUtil.generatePassword(aduser1.getValue()));

密码验证
//在用户表里查询出用户名和密码，并检验密码是否正确

Login login = loginDAO.queryByUser(userName.getValue(),CipherUtil.returnEncodeByMde(password.getValue()) );

import java.security.*;

public class Encrypter
{
	// 用MD5算法加密字符串
	public static String md5Encrypt(String s) throws Exception
	{
		//  获得支持MD5算法的MessageDigest
		MessageDigest md5 = MessageDigest.getInstance("MD5");
        //  获得BASE64Encoder对象，用Base64格式对字符串进行编码
		sun.misc.BASE64Encoder base64Encoder = new sun.misc.BASE64Encoder();
		// 对字符串进行加密，并将加密后的字符串按Base64格式进行编码，并将结果返回		
		return base64Encoder.encode(md5.digest(s.getBytes("utf-8")));
	}

}

String passwordMD5 = shopservlet.Encrypter.md5Encrypt(password);
			
			//  定义插入记录的SQL语句
			String sql = "insert into t_users(user_name, password_md5, email) values(?, ?, ?)";
			//  执行SQL语句
			execSQL(sql, userName, passwordMD5, email);			
			request.setAttribute("info", "用户注册成功!");//  定义result.jsp中使用的消息