NOT FOR COPY PASTE. Its specific code, written for a specific project, you may need to change the code in some parts.

filters.java

// Global Vars

private HashMap<ProxiedPlayer, List<List<String>>> previosMessageList = new HashMap<>();
private HashMap<ProxiedPlayer, Integer> anitSpamWarnings = new HashMap<>();


// START BAD WORD FILTER

int filteredWords = 0;
String editedMessage = e.getMessage().replaceAll("[ !.,\\-_?/&%$§\"'()\\[\\]{}=*#+~:;<>|²³`´]", "").replace("0", "o")
        .replace("1", "i").replace("2", "z").replace("3", "e").replace("4", "a")
        .replace("5", "s").replace("8", "b").toLowerCase();
for (String character : editedMessage.split(""))
    editedMessage = editedMessage.replaceAll(character + "{2,}", character);
for (String word : BungeeSystem.blacklistManager.getBlacklistedWords()) {
    if (editedMessage.contains(word.toLowerCase()))
        filteredWords++;
}
if (filteredWords > 0) {
    e.setCancelled(true);
    p.sendMessage(TextComponent.fromLegacyText(BungeeSystem.INSTANCE.getConfig().getString("filter.warning_badword_message")));
    ProxyServer.getInstance().getScheduler().runAsync(BungeeSystem.INSTANCE, () -> BungeeSystem.INSTANCE.getDiscord().sendFilterWarning(p, e.getMessage(), "Wortfilter"));
    MySQLUtils.getActiveModerators().forEach(proxiedPlayer -> {
        String notifyMessage = BungeeSystem.INSTANCE.getConfig().getString("filter.notify_message")
                .replace("{PLAYER}", p.getName())
                .replace("{MESSAGE}", e.getMessage());
        proxiedPlayer.sendMessage(TextComponent.fromLegacyText(notifyMessage));
    });
    return;
}

// END BAD WORD FILTER

// START IP, DOMAIN, LINK, EMAIL-FILTER

String[] preparedMessage = ChatColor.stripColor(ChatColor.translateAlternateColorCodes('&', e.getMessage().toLowerCase()))
        .replace(" {2,}", " ")
        .replace(" . ", ".")
        .replace(" .", ".")
        .replace("@", "")
        .split("[ /]");
for (String item : preparedMessage) {
    if (
            /*!item.matches("(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])")
            && */!item.matches("(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\\.)+[a-z][a-z-]{0,61}[a-z]")
            && !item.matches("(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)"))
        continue;
    e.setCancelled(true);
    p.sendMessage(TextComponent.fromLegacyText(BungeeSystem.INSTANCE.getConfig().getString("filter.warning_message")));
    ProxyServer.getInstance().getScheduler().runAsync(BungeeSystem.INSTANCE, () -> BungeeSystem.INSTANCE.getDiscord().sendFilterWarning(p, e.getMessage(), "Domain, Ip oder Mail-Adressen Filter"));
    MySQLUtils.getActiveModerators().forEach(proxiedPlayer -> {
        String notifyMessage = BungeeSystem.INSTANCE.getConfig().getString("filter.notify_message")
                .replace("{PLAYER}", p.getName())
                .replace("{MESSAGE}", e.getMessage());
        proxiedPlayer.sendMessage(TextComponent.fromLegacyText(notifyMessage));
    });
}

// END IP, DOMAIN, LINK, E-MAIL-FILTER

// START ANTI-SPAM

if (!BungeeSystem.INSTANCE.getPm().hasPermission(p, "antispam.bypass") &&
        !(e.getMessage().startsWith("/") || e.getMessage().startsWith("7"))) {
    List<String> preparedMessage = Arrays.asList(e.getMessage().toLowerCase().split(" "));
    List<List<String>> previousMessages = previosMessageList.computeIfAbsent(p, ignored -> new ArrayList<>());
    if (!previousMessages.isEmpty()) {
        for (List<String> message : previousMessages) {
            double i = 0;
            for (String msg : preparedMessage) {
                if (message.contains(msg))
                    i++;
            }
            double equality = i / message.size();
            if (equality > 0.85 && equality < 1.15) {
                int warnings = anitSpamWarnings.getOrDefault(p, 0) + 1;
                if (warnings > 10) {
                    ProxyServer.getInstance().getPluginManager().dispatchCommand(
                            ProxyServer.getInstance().getConsole(),
                            "mute " + p.getName() + " Spam 2h");
                    p.sendMessage(TextComponent.fromLegacyText(BungeeSystem.INSTANCE.getConfig().getString("antispam.mute_message")));
                    MySQLUtils.getActiveModerators().forEach(proxiedPlayer -> {
                        String notifyMessage = BungeeSystem.INSTANCE.getConfig().getString("antispam.mute_notify_message")
                                .replace("{PLAYER}", p.getName());
                        proxiedPlayer.sendMessage(TextComponent.fromLegacyText(notifyMessage));
                    });
                    warnings = 0;
                    e.setCancelled(true);
                } else {
                    ProxyServer.getInstance().getScheduler().schedule(BungeeSystem.INSTANCE, () -> {
                        int warings = anitSpamWarnings.getOrDefault(p, 0);
                        if (warings > 0) warings--;
                        anitSpamWarnings.put(p, warings);
                    }, 5, TimeUnit.MINUTES);
                }

                anitSpamWarnings.put(p, warnings);
                if (!e.isCancelled()) {
                    ProxyServer.getInstance().getScheduler().runAsync(BungeeSystem.INSTANCE, () -> BungeeSystem.INSTANCE.getDiscord().sendFilterWarning(p, e.getMessage(), "Spamfilter"));
                    p.sendMessage(TextComponent.fromLegacyText(BungeeSystem.INSTANCE.getConfig().getString("antispam.warning_message")));
                    e.setCancelled(true);
                }
                break;
            }
        }
    }
    if (previousMessages.size() > 2)
        previousMessages.remove(0);
    previousMessages.add(preparedMessage);
    ProxyServer.getInstance().getScheduler().schedule(BungeeSystem.INSTANCE, () -> previousMessages.remove(preparedMessage), 30, TimeUnit.SECONDS);
}

// END ANTI-SPAM

// BLACKLIST MANAGER

public class BlacklistManager {

    private final ArrayList<String> blacklistedWords;
    private final Configuration config;
    private final File file;

    public BlacklistManager() throws IOException {
        file = new File(BungeeSystem.INSTANCE.getDataFolder().getPath(), "blacklist.yml");
        if (!file.exists()) {
            file.createNewFile();
        }
        config = ConfigurationProvider.getProvider(YamlConfiguration.class).load(file);
        blacklistedWords = (ArrayList<String>) config.getList("words", new ArrayList<>());
    }

    public void addWords(List<String> words) {
        blacklistedWords.addAll(words);
        save();
    }

    private void save() {
        config.set("words", blacklistedWords);
        try {
            ConfigurationProvider.getProvider(YamlConfiguration.class).save(config, file);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void removeWords(List<String> words) {
        blacklistedWords.removeAll(words);
        save();
    }

    public ArrayList<String> getBlacklistedWords() {
        return blacklistedWords;
    }
}