MD5加密工具类-Java

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @author ycjstart
 * @create 2022-11-23 21:19
 */
public class MD5Util {

    /**
     * 针对明文字符串执行MD5加密
     */
    public static String encode(String source) {

        // 1.判断明文字符串是否有效
        if (source == null || "".equals(source)) {
            throw new RuntimeException("用于加密的明文不可为空");
        }

        // 2.声明算法名称
        String algorithm = "md5";

        // 3.获取MessageDigest对象
        MessageDigest messageDigest = null;
        try {
            messageDigest = MessageDigest.getInstance(algorithm);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }

        // 4.获取明文字符串对应的字节数组
        byte[] input = source.getBytes();

        // 5.执行加密
        assert messageDigest != null;
        byte[] output = messageDigest.digest(input);

        // 6.创建BigInteger对象
        int signum = 1;
        BigInteger bigInteger = new BigInteger(signum, output);

        // 7.按照16进制将bigInteger的值转换为字符串
        int radix = 16;

        return bigInteger.toString(radix).toUpperCase();
    }

}