extras/src/main/java/pw/kaboom/extras/commands/CommandBroadcastRainbow.java

package pw.kaboom.extras.commands;

import net.kyori.adventure.text.Component;
import net.kyori.adventure.text.format.NamedTextColor;
import net.kyori.adventure.text.minimessage.MiniMessage;
import org.bukkit.Bukkit;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;

import javax.annotation.Nonnull;

public final class CommandBroadcastRainbow implements CommandExecutor {
    private static final MiniMessage MINI_MESSAGE = MiniMessage.miniMessage();

    public boolean onCommand(final @Nonnull CommandSender sender,
                             final @Nonnull Command command,
                             final @Nonnull String label,
                             final String[] args) {
        if (args.length == 0) {
            sender.sendMessage(Component
                    .text("Usage: /" + label + " <message ..>",
                            NamedTextColor.RED));
            return true;
        }
        final String strippedTags = MINI_MESSAGE.stripTags(String.join(" ", args));
        final Component component = MINI_MESSAGE.deserialize("<rainbow>" + strippedTags);
        Bukkit.getServer().broadcast(component);
        return true;
    }
}