ziemnia watcher

package com.example.threadpoller;

import com.google.gson.*;
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.entity.Player;
import org.bukkit.plugin.java.JavaPlugin;

import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class ThreadPoller extends JavaPlugin implements CommandExecutor {
    private ScheduledExecutorService scheduler;
    private Set<Long> seenPosts = new HashSet<>();
    private FileConfiguration cfg;
    private Boolean bFirst;

    @Override
    public void onEnable() {
        saveDefaultConfig();
        cfg = getConfig();
        bFirst = true;
        getCommand("pollreload").setExecutor(this);
        startPolling();
    }

    @Override
    public void onDisable() {
        if (scheduler != null)
            scheduler.shutdownNow();
    }

    private void startPolling() {
        if (scheduler != null)
            scheduler.shutdownNow();
        scheduler = Executors.newSingleThreadScheduledExecutor();
        int interval = cfg.getInt("interval-seconds", 30);
        scheduler.scheduleAtFixedRate(this::pollOnce, 0, interval, TimeUnit.SECONDS);
    }

    private void pollOnce() {
        try {
            String urlStr = cfg.getString("url");
            HttpURLConnection conn = (HttpURLConnection) new URL(urlStr).openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5000);
            conn.setReadTimeout(5000);

            conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                    + "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36");
            conn.setRequestProperty("Accept", "application/json");
            conn.setRequestProperty("Accept-Language", "en-US,en;q=0.9");
            conn.setRequestProperty("Referer", "https://ziemniachan.org/");
            conn.setRequestProperty("Connection", "keep-alive");

            JsonObject root = JsonParser.parseReader(
                    new InputStreamReader(conn.getInputStream())).getAsJsonObject();
            JsonArray posts = root.getAsJsonArray("posts");
            String prefix = cfg.getString("prefix", "[fred na ziemniaku]");

            for (JsonElement el : posts) {
                JsonObject post = el.getAsJsonObject();
                long no = post.get("no").getAsLong();
                if (!seenPosts.contains(no)) {
                    seenPosts.add(no);
                    if (bFirst) {
                        continue;
                    }
                    String raw = post.has("com") ? post.get("com").getAsString() : "";
                    String noHtml = raw.replaceAll("(?i)<[^>]*>", "");
                    noHtml = noHtml.replaceAll("^(>+[0-9]+)", "$1 ");
                    String com = noHtml.replace("&gt;", ">")
                            .replace("&lt;", "<")
                            .replace("&amp;", "&");
                    String message = ChatColor.RED + prefix +
                            ChatColor.GREEN + "<" + no + ">" +
                            ChatColor.YELLOW + ": " + com;

                    Bukkit.getScheduler().runTask(this, () -> Bukkit.broadcastMessage(message));
                }
            }

            bFirst = false;
        } catch (Exception e) {
            getLogger().warning("Error polling thread: " + e.getMessage());
        }
    }

    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if (command.getName().equalsIgnoreCase("pollreload")) {
            reloadConfig();
            cfg = getConfig();
            seenPosts.clear();
            startPolling();
            sender.sendMessage(ChatColor.GREEN + "ThreadPoller reloaded.");
            return true;
        }
        return false;
    }
}z