/**
 * @author hcy
 * @version 1.0
 * @date 2020/3/1 下午6:37
 */
public class Test2 {
    //待加密的密码
    public static String password = "123456";

    public static void main(String args[]) {
        //结果字符串
        String result = "";
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(password.getBytes());
            byte b[] = md.digest();
            int i;
            StringBuffer buf = new StringBuffer("");
            for (int offset = 0; offset < b.length; offset++) {
                i = b[offset];
                if (i < 0)
                    i += 256;
                if (i < 16)
                    buf.append("0");
                buf.append(Integer.toHexString(i));
            }
            result = buf.toString();
            System.out.println("MD5(" + password + ",32小写) = " + result);
            System.out.println("MD5(" + password + ",32大写) = " + result.toUpperCase());
            System.out.println("++++++++++++++++++++++++ 看结果咯   +++++++++++++++++++++++");
            System.out.println("MD5(" + password + ",16小写) = " + buf.toString().substring(8, 24));
            System.out.println("MD5(" + password + ",16大写) = " + buf.toString().substring(8, 24).toUpperCase());
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
    }
}
Connected to the target VM, address: '127.0.0.1:36603', transport: 'socket'
MD5(123456,32小写) = e10adc3949ba59abbe56e057f20f883e
MD5(123456,32大写) = E10ADC3949BA59ABBE56E057F20F883E
++++++++++++++++++++++++ 看结果咯   +++++++++++++++++++++++
MD5(123456,16小写) = 49ba59abbe56e057
MD5(123456,16大写) = 49BA59ABBE56E057