Ore Shrooms - spigot 1.11.2

Main.java

package tutorial.spigot.plugins;

import org.bukkit.plugin.java.JavaPlugin;

public class Main extends JavaPlugin{

	@Override
	public void onEnable() {
		getLogger().info("Dr Ewe's plugin is enabled");
		getServer().getPluginManager().registerEvents(new OreShrooms(), this);
	}
	
	@Override
	public void onDisable() {
		getLogger().info("Dr Ewe's plugin is disabled");
	}
	
}

OreShrooms.java

package tutorial.spigot.plugins;

import java.util.Random;

import org.bukkit.Material;
import org.bukkit.TreeType;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.world.StructureGrowEvent;

public class OreShrooms implements Listener {
	
	@EventHandler
	public void makeOreBlocks(StructureGrowEvent event) {
		Material replaceWith = Material.AIR;
		
		if ((event.getSpecies() != TreeType.BROWN_MUSHROOM) && (event.getSpecies() != TreeType.RED_MUSHROOM)) {
			return;
		}
			
		Random rand = new Random();
		
		for (int block = 0; block < event.getBlocks().size(); block++) {
			switch (rand.nextInt(5)) {
			
			case 0:
				replaceWith = Material.DIAMOND_BLOCK;
				break;
			case 1:
				replaceWith = Material.EMERALD_BLOCK;
				break;
			case 2:
				replaceWith = Material.IRON_BLOCK;
				break;
			case 3:
				replaceWith = Material.GOLD_BLOCK;
				break;
			case 4:
				if (event.getSpecies() == TreeType.BROWN_MUSHROOM) {
					replaceWith = Material.HUGE_MUSHROOM_1;
				} else if (event.getSpecies() == TreeType.RED_MUSHROOM) {
					replaceWith = Material.HUGE_MUSHROOM_2;
				}
				break;
			}
			event.getBlocks().get(block).setType(replaceWith);
		}
	}
}