Is changing Vanilla Entities attributes in minecraft Java in the files possible ?

[MiiG]

So im completely new to modding in general, i have some experience in Behavior packs in minecraft bedrock and i would like to modify entities stats and attributes like in a behavior pack (health, damage, speed, xp drop...). The problem is that i cant find any information online on how to do that, and I have no clue on what to do and where to start. I am currently modding in 1.20.4 with IntelliJ if that helps. My final objective is to buff mobs health and damage (double it for exemple), but since there is no entity file anywhere i don't know how to change it... 😢

[MiiG]

Update, i found a way to do that, and it was a pain in the ass to find accurate information online and on my version so i used chatgpt for the research and ended up finding a piece of code somewhere that i had to place in my MOD.java file. It's using events so that right now, i can modify the attributes i wanted, if it can help anyone else here's the code in question, i think it can also work in other versions 👍 :
 

@SubscribeEvent
        public static void onEntityJoin(EntityJoinLevelEvent event) {
            if (event.getEntity() instanceof Zombie zombie) {
                // Change stats
                Objects.requireNonNull(zombie.getAttribute(Attributes.MAX_HEALTH)).setBaseValue(40.0D);
                zombie.setHealth(40.0F); // Also set current health
                Objects.requireNonNull(zombie.getAttribute(Attributes.ATTACK_DAMAGE)).setBaseValue(10.0D);
                Objects.requireNonNull(zombie.getAttribute(Attributes.MOVEMENT_SPEED)).setBaseValue(0.35D); } }
        @SubscribeEvent
        public static void onXpDrop(net.minecraftforge.event.entity.living.LivingExperienceDropEvent event) {
            if (event.getEntity() instanceof Zombie) {
                int newXp = 100; // Set custom XP amount here
                event.setDroppedExperience(newXp);