Optional In the Wild

StoneBreakingListener.java

package com.krinchan.minecraft.spongediamondfinder.listeners;

import org.slf4j.Logger;
import org.spongepowered.api.entity.living.player.Player;
import org.spongepowered.api.event.Listener;
import org.spongepowered.api.event.block.ChangeBlockEvent;

/**
 * Created by david on 2/6/16.
 */
public class StoneBreakingListener {

    Logger logger;

    public StoneBreakingListener(Logger logger) {
        this.logger = logger;
    }

    @Listener
    public void handle(ChangeBlockEvent.Break event) throws Exception {
        String playerString = event.getCause().first(Player.class) //Returns Optional<Player>
                .map(player -> player.getName() + "/" + player.getUniqueId().toString())
                .orElse("UNKNOWN");

        String blockName = event.getTransactions().get(0).getFinal().getState().getType().getName();

        logger.info(String.format("Player %s broke %s",
                playerString, blockName));
    }
}