How to compute MD5 hash of a string in Java?

Hi everyone! I just started learning Java and came across a task: I need to compute the MD5 hash of a string to check file integrity. I've searched through many forums, but everywhere the examples are either outdated or too complicated for a beginner. I tried to write the code myself, but it doesn't work. Here's what I got: ```java public class MD5Example { public static void main(String[] args) { String input = "Hello, world!"; String hash = input.hashCode(); // I know this is wrong System.out.println("MD5: " + hash); } } ``` I understand that `hashCode()` is not MD5, just Java's internal hash. But how to do it correctly? I've heard about `MessageDigest`, but I don't understand how to use it. Do I need to include any libraries? Or can I do it with standard tools?