md5digest.java

一个简单的Java实现MD5加密的程序

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Digest
{

    private MessageDigest __md5 = null;
    private StringBuffer __digestBuffer = null;

    public MD5Digest()
        throws NoSuchAlgorithmException
    {
        __md5 = MessageDigest.getInstance("MD5");
        __digestBuffer = new StringBuffer();
    }

    public String md5crypt(String s)
    {
        __digestBuffer.setLength(0);
        byte abyte0[] = __md5.digest(s.getBytes());
        for(int i = 0; i < abyte0.length; i++)
            __digestBuffer.append(toHex(abyte0[i]));

        return __digestBuffer.toString();
    }
    public String toHex(byte one){
   String HEX="0123456789ABCDEF";
   char[] result=new char[2];
   result[0]=HEX.charAt((one & 0xf0) >> 4);
   result[1]=HEX.charAt(one & 0x0f);
   String mm=new String(result);
   return mm;
  }
}