对于数据库中用户密码的加密三种方式

package simple;

import io.netty.handler.codec.base64.Base64Encoder;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import java.io.IOException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;


public class Test {
    public static void main(String[] args) throws NoSuchAlgorithmException, IOException {
        String s = "asdasdassdasa";

        //MD5 加密单向，不可逆
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        md5.update(s.getBytes());
        //System.out.println(new BigInteger(1, md5.digest()).toString(16));

        //sha 加密单向，不可逆
        MessageDigest sha = MessageDigest.getInstance("SHA");
        sha.update(s.getBytes());
        //System.out.println(new BigInteger(1, sha.digest()).toString(16));

        //BASE64 加密，可逆
        String encode = (new BASE64Encoder()).encode(s.getBytes());
        System.out.println(encode);
        byte[] bytes = (new BASE64Decoder()).decodeBuffer(encode);
        System.out.println(new String(bytes));

    }
}