java之MessageDigest简单使用总结

   

    

     

      

     
     

      

       public class MD5AndSHA {  
      
     
    

     

      

     
     

      
 
      
     
    

     

      

     
     

      

        public final static String MD5_SHA(String s, String method) {  
      
     
    

     

      

     
     

      

        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',  
      
     
    

     

      

     
     

      

        'a', 'b', 'c', 'd', 'e', 'f' };  
      
     
    

     

      

     
     

      

        try {  
      
     
    

     

      

     
     

      

        byte[] strTemp = s.getBytes();  
      
     
    

     

      

     
     

      

        //如果输入“SHA”，就是实现SHA加密。  
      
     
    

     

      

     
     

      

        MessageDigest mdTemp = MessageDigest.getInstance(method);   
      
     
    

     

      

     
     

      

        mdTemp.update(strTemp);  
      
     
    

     

      

     
     

      

        byte[] md = mdTemp.digest();  
      
     
    

     

      

     
     

      

        int j = md.length;  
      
     
    

     

      

     
     

      

        char str[] = new char[j * 2];  
      
     
    

     

      

     
     

      

        int k = 0;  
      
     
    

     

      

     
     

      

        for (int i = 0; i < j; i++) { 
      
     
    

     

      

     
     

      
 byte byte0 = md[i];  
      
     
    

     

      

     
     

      
 str[k++] = hexDigits[byte0 >>> 4 & 0xf];  
      
     
    

     

      

     
     

      

        str[k++] = hexDigits[byte0 & 0xf];  
      
     
    

     

      

     
     

      

        }  
      
     
    

     

      

     
     

      

        return new String(str);  
      
     
    

     

      

     
     

      

        } catch (Exception e) {  
      
     
    

     

      

     
     

      

        return null;  
      
     
    

     

      

     
     

      

        }  
      
     
    

     

      

     
     

      

        }  
      
     
    

     

      

     
     

      
  
      
     
    

     

      

     
     

      

        public static void main(String[] args) {  
      
     
    

     

      

     
     

      

        //System.out.print(MD5AndSHA.MD5_SHA("123456"), "MD5");  
      
     
    

     

      

     
     

      

       	//System.out.print(MD5AndSHA.MD5_SHA("123456"), "SHA");  
      
     
    

     

      

     
     

      

        }  
      
     
    

     

      

     
     

      

       }