MD5加密算法

import java.security.*;
import java.security.spec.*;
class MD5_Test...{
    
    public final static String MD5(String s)...{
        char hexDigits[] = ...{''0'', ''1'', ''2'', ''3'', ''4'', ''5'', ''6'', ''7'', ''8'', ''9'', ''a'', ''b'', ''c'', ''d'',''e'', ''f''};
        try
        ...{
            byte[] strTemp = s.getBytes();
            MessageDigest mdTemp = MessageDigest.getInstance("MD5");
            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 ;
                str[k++] = hexDigits[byte0 >>>4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str);
        }
        catch (Exception e)
        ...{
            return null;
        }
    }
}

主程序如下：


public class md5_main ...{
    public static void main (String[] args)
    ...{
        //MD5_Test aa = new MD5_Test("password");
        String string= MD5_Test.MD5("password");
        System.out.println(MD5_Test.MD5("password"));
        System.out.println(string.equals("5f4dcc3b5aa765d61d8327deb882cf99"));
    }
}