Am I doing anything wrong using CreatureSpawnEvent?

I have a code that looks like this:

Code:

@EventHandler
public void onCreatureSpawnEvent(CreatureSpawnEvent event)
{
    // Some code that doesn't run at all when a mob spawns
}

However, the code doesn't even run when a mob spawns. Am I doing anything wrong?

 

I didn't, sorry, I'm new to Java. Now I registered the listener and then... my system crashed.
After testing with /gamerule doMobSpawning, it's making a NPE every time I spawn a mob.

 

Yes, unfortunately, probably because the server somehow ate up all of my RAM.

 

Just giving some boosts to mobs that spawn in by a random chance.
It doesn't happen anymore though.
Here's my code:

Code:

public class CreatureSpawnHandler implements Listener {
private Main plugin;Random r = new Random();@EventHandlerpublic void onCreatureSpawnEvent (CreatureSpawnEvent event) {
if (Main.getInstance().isNight) {
LivingEntity entity = event.getEntity();EntityType type = event.getEntityType(); if (type.equals(EntityType.ZOMBIE)) {
entity.getAttribute(Attribute.GENERIC_MAX_HEALTH).setBaseValue(40);entity.setHealth(40); if (r.nextFloat() <= .35) {
entity.getEquipment().setItemInMainHand(new ItemStack(Material.IRON_SWORD));}
if (r.nextFloat() <= .1) {
entity.addPotionEffect(new PotionEffect(PotionEffectType.SPEED, 10000000, 0));}
} else if (type.equals(EntityType.SKELETON)) {
entity.addPotionEffect(new PotionEffect(PotionEffectType.SPEED, 10000000, 0));} else if (type.equals(EntityType.SPIDER)) {
entity.addPotionEffect(new PotionEffect(PotionEffectType.DAMAGE_RESISTANCE, 10000000, 1));}
}
}
}

Wonder why bukkit breaks indentations and some newlines.
+ No errors on the editor side.
++ I think the crash was just a coincidence, it doesn't happen anymore whatever I do.

Fixed it! Main.getInstance() was returning null and I just needed to correct that.