PlaceholderUtil

InternalPlaceholder.java

package mc.obliviate.masterduels.utils.placeholder;

public class InternalPlaceholder {

	private final String placeholder;
	private final String value;

	protected InternalPlaceholder(final String placeholder, final String value) {
		this.placeholder = placeholder;
		this.value = value;
	}

	public String getPlaceholder() {
		return placeholder;
	}

	public String getValue() {
		if (value == null) return "";
		return value;
	}
}

PlaceholderUtil.java

package mc.obliviate.masterduels.utils.placeholder;

import java.util.ArrayList;
import java.util.List;

public class PlaceholderUtil {

	private final List<InternalPlaceholder> placeholders = new ArrayList<>();

	public PlaceholderUtil add(final String key, final String value) {
		placeholders.add(new InternalPlaceholder(key, value));
		return this;
	}

	public List<InternalPlaceholder> getPlaceholders() {
		return placeholders;
	}

	public List<String> apply(final List<String> texts) {
		final List<String> result = new ArrayList<>();
		for (final String text : texts) {
			result.add(apply(text));
		}
		return result;
	}
	public String apply(String text) {
		for (final InternalPlaceholder placeholder : placeholders) {
			text = text.replace(placeholder.getPlaceholder(), placeholder.getValue());
		}
		return text;
	}


}

Compatible with Message Utils gist.

Example Usage:

MessageUtils.sendMessage(player, "queue.queue-not-found", new PlaceholderUtil().add("{player}", player.getName()));