minecraft plugin empty hand cause double right click

In Minecraft, if you're developing a plugin (usually using the Spigot or Bukkit API) and you want to implement a feature where a player right-clicking with an empty hand causes a double right-click action, you will need to listen for player interaction events and check if the player is holding nothing.

Here's a simple outline of how you could implement this:

1. **Listen for PlayerInteractEvent**: This event is triggered whenever a player interacts with the world or an object. You'll want to check for right-click actions.

2. **Check for Empty Hand**: Determine if the player's hand is empty when they right-click.

3. **Handle Double Click**: For the double-click behavior, you may need to keep track of the time between clicks to decide whether to trigger your custom behavior.

Here’s a basic implementation in Java:

```java
import org.bukkit.Bukkit;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerInteractEvent;
import org.bukkit.event.player.PlayerInteractEntityEvent;
import org.bukkit.inventory.ItemStack;
import org.bukkit.plugin.java.JavaPlugin;

import java.util.HashMap;
import java.util.Map;

public class MyPlugin extends JavaPlugin implements Listener {
    private Map<String, Long> lastClickTimes = new HashMap<>();

    @Override
    public void onEnable() {
        Bukkit.getPluginManager().registerEvents(this, this);
    }

    @EventHandler
    public void onPlayerInteract(PlayerInteractEvent event) {
        // Check if the action is a right-click
        if (event.getAction().toString().contains("RIGHT")) {
            ItemStack item = event.getItem();
            // Check if the player is holding an empty hand
            if (item == null || item.getAmount() == 0) {
                String playerName = event.getPlayer().getName();
                long currentTime = System.currentTimeMillis();

                // Check if this is the second click within a certain timeframe (e.g., 300 milliseconds)
                if (lastClickTimes.containsKey(playerName) &&
                        (currentTime - lastClickTimes.get(playerName) <= 300)) {
                    // Handle double right-click action
                    event.getPlayer().sendMessage("You double right-clicked with an empty hand!");

                    // Clear the record to prevent further processing of double click
                    lastClickTimes.remove(playerName);
                } else {
                    // Record the time of the current click
                    lastClickTimes.put(playerName, currentTime);
                }
            }
        }
    }
}
```

### Explanation:
1. **Event Listener**: The plugin registers an event listener for `PlayerInteractEvent`.
2. **Check Right-Click**: It checks if the action is a right-click (either block or entity interactions).
3. **Empty Hand Check**: It verifies if the player is holding nothing.
4. **Double Click Handling**: It timestamps each click and checks if the second click occurs within a specified timeframe (300 milliseconds in this case).
5. **Message on Double Click**: If it detects a double-click, it sends a message to the player.

### Deployment:
- Ensure you have a suitable development environment with Spigot or Bukkit API available.
- Compile your plugin as a `.jar` and place it in the `plugins` folder of your Minecraft server.
- Start the server and test the behavior.

### Note:
Please adjust the time frame and responses according to your needs. The above implementation is quite basic and might need more robust handling based on your plugin's complexity!