Bukkit Dev' | #2 - Double Jumps

import org.bukkit.GameMode;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerMoveEvent;
import org.bukkit.event.player.PlayerToggleFlightEvent;
import org.bukkit.plugin.java.JavaPlugin;

public class DoubleJump extends JavaPlugin implements Listener {

	public void onEnable() {
		getServer().getPluginManager().registerEvents(this, this);
	}

	@EventHandler
	public void onPlayerToggleFlight(PlayerToggleFlightEvent event) {
		Player player = event.getPlayer();
		if (player.getGameMode() == GameMode.CREATIVE)
			return;
		event.setCancelled(true);
		player.setAllowFlight(false);
		player.setFlying(false);
		player.setVelocity(player.getLocation().getDirection().multiply(1.5).setY(1));
	}

   @EventHandler
   public void onPlayerMove(PlayerMoveEvent event) {
	   Player player = event.getPlayer();
	   if ((player.getGameMode() != GameMode.CREATIVE)&&(player.getLocation().subtract(0, 1, 0).getBlock().getType() !=Material.AIR)&&(!player.isFlying())) {
		   player.setAllowFlight(true);
	   }

   }


}