https://hub.spigotmc.org/jira/browse/SPIGOT-882

import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerDropItemEvent;
import org.bukkit.plugin.java.JavaPlugin;

public class TestPlugin extends JavaPlugin implements Listener
{
    @Override
    public void onEnable()
    {
        getServer().getPluginManager().registerEvents(this, this);
    }

    @EventHandler(ignoreCancelled = true)
    void on(PlayerDropItemEvent event)
    {
        getLogger().info("Player Drop Item Event: player:"+event.getPlayer()+" drop:"+event.getItemDrop());
        event.setCancelled(true);
    }
}