Developer Documentation v2.0

Minecraft Plugin Integration

Complete guide for integrating UlisesLib with Minecraft plugins

UlisesLib.jar 23rd June, 2026

Updated library with enhanced connectivity and detailed license information methods.

Minecraft Plugin Integration

1. Load Configuration File

private void loadAntileakConfig() {
    File krakenDir = getDataFolder();
    if (!krakenDir.exists()) {
        krakenDir.mkdirs();
    }

    File antileakFile = new File(krakenDir, "antileak.yml");
    if (!antileakFile.exists()) {
        try {
            antileakFile.createNewFile();
            this.antileakConfig = YamlConfiguration.loadConfiguration(antileakFile);
            this.antileakConfig.set("license.key", "your-license-key-here");
            this.antileakConfig.save(antileakFile);
        } catch (IOException e) {
            e.printStackTrace();
        }
    } else {
        this.antileakConfig = YamlConfiguration.loadConfiguration(antileakFile);
    }
}

2. License Validation with Retry Logic

private void validateLicense() {
    UlisesLib ulib = new UlisesLib();
    Sring productid = "myproductid";
    String licenseKey = this.antileakConfig.getString("license.key", "");
   
    boolean licenseValid = false;
    while (!licenseValid) {
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
Id, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
y)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
ctId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
seKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
ductId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
icenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
roductId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
d, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
uctId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
me(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
n
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
(productId, licenseKey);
            String productName = ulib.getProductName(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
dId = ulib.getDiscordId(productId, licenseKey);
            String productName = ulib.getProductName(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
g expiresAt = ulib.getExpirationDate(productId, licenseKey);
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
            String productName = ulib.getProductName(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.DARK_AQUA + "✓ Authentication successful. Powering up Kraken..."
            );
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.GRAY + " » Discord ID: " + ChatColor.AQUA + discordId
            );
            
            // Continue loading your plugin...
            loadPlugin();
            
        } else {
            String lastError = ulib.getLastError();
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.RED + "✗ License authentication failed: " + lastError
            );
            
            if (lastError != null && lastError.contains("Unable to connect to the backend server")) {
                Bukkit.getConsoleSender().sendMessage(
                    ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                    ChatColor.YELLOW + "⚠ Retrying connection in 30 seconds..."
                );
                
                try {
                    Thread.sleep(30000);
                } catch (InterruptedException e) {
                    Bukkit.getPluginManager().disablePlugin(this);
                    return;
                }
            } else {
                Bukkit.getPluginManager().disablePlugin(this);
                return;
            }
        }
    }
}

3. Periodic Security Checks

private void startSecurityChecks() {
    ScheduledExecutorService licenseService = Executors.newSingleThreadScheduledExecutor();
    
    licenseService.scheduleAtFixedRate(() -> {
        UlisesLib ulib = new UlisesLib();
        String productId = antileakConfig.getString("license.product-id", "");
        String licenseKey = antileakConfig.getString("license.key", "");
        
        if (!ulib.isLicenseValid(productId, licenseKey)) {
            String lastError = ulib.getLastError();
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.RED + "✗ License validation failed during periodic check."
            );
            
            if (lastError != null && lastError.contains("Unable to connect to the backend server")) {
                Bukkit.getConsoleSender().sendMessage(
                    ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                    ChatColor.YELLOW + "⚠ Will retry in next check cycle..."
                );
            } else {
                Bukkit.getScheduler().runTask(this, () -> Bukkit.getPluginManager().disablePlugin(this));
                licenseService.shutdown();
            }
        } else {
            // Display successful check with details
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.GREEN + "✓ License check passed. Status: " + 
                ulib.getLicenseStatus(productId, licenseKey)
            );
        }
    }, 10L, 10L, TimeUnit.MINUTES);
}

Complete Plugin Example

public class KrakenAntiCheat extends JavaPlugin {
    private FileConfiguration antileakConfig;
    
    @Override
    public void onEnable() {
        loadAntileakConfig();
        
        String productId = antileakConfig.getString("license.product-id");
        String licenseKey = antileakConfig.getString("license.key");
        
        if (productId.equals("your-product-id-here") || licenseKey.equals("your-license-key-here")) {
            getLogger().severe("License details not configured. Please edit antileak.yml");
            Bukkit.getPluginManager().disablePlugin(this);
            return;
        }
        
        validateLicense(productId, licenseKey);
    }
    
    private void validateLicense(String productId, String licenseKey) {
        UlisesLib ulib = new UlisesLib();
        
        while (true) {
            if (ulib.isLicenseValid(productId, licenseKey)) {
                // License is valid - continue loading plugin
                String discordId = ulib.getDiscordId(productId, licenseKey);
                String expiresAt = ulib.getExpirationDate(productId, licenseKey);
                
                getLogger().info("License validated for Discord ID: " + discordId);
                getLogger().info("License expires: " + expiresAt);
                
                // Load your plugin features
                loadFeatures();
                startPeriodicChecks();
                break;
                
            } else {
                String error = ulib.getLastError();
                getLogger().severe("License validation failed: " + error);
                
                if (error != null && error.contains("Unable to connect to the backend server")) {
                    getLogger().warning("Retrying connection in 30 seconds...");
                    try {
                        Thread.sleep(30000);
                    } catch (InterruptedException e) {
                        Bukkit.getPluginManager().disablePlugin(this);
                        break;
                    }
                } else {
                    Bukkit.getPluginManager().disablePlugin(this);
                    break;
                }
            }
        }
    }
    
    private void startPeriodicChecks() {
        Bukkit.getScheduler().runTaskTimerAsynchronously(this, () -> {
            UlisesLib ulib = new UlisesLib();
            String productId = antileakConfig.getString("license.product-id");
            String licenseKey = antileakConfig.getString("license.key");
            
            if (!ulib.isLicenseValid(productId, licenseKey)) {
                String error = ulib.getLastError();
                getLogger().severe("Periodic license check failed: " + error);
                
                if (!error.contains("Unable to connect to the backend server")) {
                    Bukkit.getScheduler().runTask(this, () -> 
                        Bukkit.getPluginManager().disablePlugin(this)
                    );
                }
            } else {
                getLogger().info("Periodic license check passed.");
            }
        }, 20L * 60 * 10, 20L * 60 * 10); // Every 10 minutes
    }
}

Enhanced API Methods

String getDiscordId(String productId, String licenseKey)

Retrieves the Discord ID associated with the license. Returns null if validation fails.

String discordId = ulib.getDiscordId(productId, licenseKey);
// Returns: "1216532655592439862"

String getProductName(String productId, String licenseKey)

Retrieves the product name from the license. Returns null if validation fails.

String productName = ulib.getProductName(productId, licenseKey);
// Returns: "KrakenAnticheat"

String getExpirationDate(String productId, String licenseKey)

Retrieves the expiration date in ISO format. Returns null if validation fails.

String expiresAt = ulib.getExpirationDate(productId, licenseKey);
// Returns: "2025-12-05T00:00:00.000Z"

String getLicenseStatus(String productId, String licenseKey)

Retrieves the license status (active/revoked/expired). Returns null if validation fails.

String status = ulib.getLicenseStatus(productId, licenseKey);
// Returns: "active"

String getSubType(String productId, String licenseKey)

Retrieves the license subtype (Enterprise, Advanced, etc). Returns null if validation fails.

String subType = ulib.getSubType(productId, licenseKey);
// Returns: "Enterprise"

String getLastError()

Returns the last error message. Useful for debugging connection issues.

Connection Management

Automatic Reconnection

The library now handles connection issues automatically

Infinite Retry: When backend is unreachable, the library retries every 30 seconds until successful

Clear Messages: Console shows "Unable to connect to the backend server" with retry countdown

Graceful Handling: Only disables plugin for actual license issues, not connection problems

Important Note for Plugin Developers

Your plugin should continue running normally during connection issues. Only disable the plugin when there are actual license validation failures (expired, revoked, invalid). Connection problems should trigger retry attempts, not immediate shutdown.

Auto-Update Integration

UlisesLib includes built-in methods for checking updates, downloading the latest jar, and verifying its integrity. All security validations (license status, HWID binding, IP limits) are handled automatically by the library.

boolean checkForUpdate(String productId, String licenseKey, String currentVersion)

Checks if a newer version of the product jar is available. Returns true if an update exists.

String currentVersion = "1.0.0";
if (ulib.checkForUpdate(productId, licenseKey, currentVersion)) {
    getLogger().info("Update available! Downloading...");
    ulib.downloadUpdate(productId, licenseKey, hwid);
}

File downloadUpdate(String productId, String licenseKey, String hwid)

Downloads the latest jar file. Automatically handles HWID binding on first download. Returns the downloaded File, or null if download fails.

String hwid = ulib._getHwid();
File updatedJar = ulib.downloadUpdate(productId, licenseKey, hwid);
if (updatedJar != null) {
    getLogger().info("Update downloaded: " + updatedJar.getName());
    // Optionally verify checksum
    if (ulib.verifyChecksum(productId, licenseKey, hwid, updatedJar)) {
        getLogger().info("Checksum verified!");
    }
}

boolean verifyChecksum(String productId, String licenseKey, String hwid, File jarFile)

Verifies the SHA-256 checksum of the downloaded jar file to ensure file integrity.

File jarFile = new File("plugins/MyPlugin.jar");
boolean valid = ulib.verifyChecksum(productId, licenseKey, hwid, jarFile);
if (!valid) {
    getLogger().warning("Checksum mismatch! File may be corrupted.");
}

String getCurrentVersion(String productId, String licenseKey)

Returns the latest version string of the product jar available on the server.

String latestVersion = ulib.getCurrentVersion(productId, licenseKey);
getLogger().info("Latest version available: " + latestVersion);

Security Validations

All update operations automatically validate:

License Status: Only active, non-expired licenses can download updates

HWID Binding: Hardware ID is validated and bound to the license on first download

IP Limit: Respects the IP limit configured per license

Complete Auto-Update Example

private void checkAndApplyUpdate(String productId, String licenseKey) {
    String currentVersion = this.getDescription().getVersion();
    String hwid = ulib.getHardwareId();

    // Check if update is available
    if (ulib.checkForUpdate(productId, licenseKey, currentVersion)) {
        String latestVersion = ulib.getCurrentVersion(productId, licenseKey);
        getLogger().info("New version available: " + latestVersion + " (current: " + currentVersion + ")");

        // Download the update
        File updatedJar = ulib.downloadUpdate(productId, licenseKey, hwid);
        if (updatedJar != null) {
            // Verify integrity
            if (ulib.verifyChecksum(productId, licenseKey, hwid, updatedJar)) {
                getLogger().info("Update downloaded and verified successfully!");
                getLogger().info("Restart the server to apply the update.");
            } else {
                getLogger().warning("Checksum verification failed. Update may be corrupted.");
            }
        }
    } else {
        getLogger().info("Plugin is up to date.");
    }
}

Best Practices

✓

Do This

Use infinite retry loops for connection issues
Display detailed license information on successful validation
Implement periodic checks (every 10 minutes)
Create configuration file with default values

✗

Avoid This

Disabling plugin on connection timeout
Hardcoding credentials in source code
Exposing error details to end users
Running validation on main thread

Developer Documentation v2.0

Minecraft Plugin Integration

Complete guide for integrating UlisesLib with Minecraft plugins

UlisesLib.jar 23rd June, 2026

Updated library with enhanced connectivity and detailed license information methods.

Download UlisesLib.jar v2.0

Minecraft Plugin Integration

1. Load Configuration File

private void loadAntileakConfig() {
    File krakenDir = getDataFolder();
    if (!krakenDir.exists()) {
        krakenDir.mkdirs();
    }

    File antileakFile = new File(krakenDir, "antileak.yml");
    if (!antileakFile.exists()) {
        try {
            antileakFile.createNewFile();
            this.antileakConfig = YamlConfiguration.loadConfiguration(antileakFile);
            this.antileakConfig.set("license.key", "your-license-key-here");
            this.antileakConfig.save(antileakFile);
        } catch (IOException e) {
            e.printStackTrace();
        }
    } else {
        this.antileakConfig = YamlConfiguration.loadConfiguration(antileakFile);
    }
}

2. License Validation with Retry Logic

private void validateLicense() {
    UlisesLib ulib = new UlisesLib();
    Sring productid = "myproductid";
    String licenseKey = this.antileakConfig.getString("license.key", "");
   
    boolean licenseValid = false;
    while (!licenseValid) {
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
Id, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
y)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
ctId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
seKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
ductId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
icenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
roductId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
d, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
uctId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
me(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
n
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
(productId, licenseKey);
            String productName = ulib.getProductName(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
dId = ulib.getDiscordId(productId, licenseKey);
            String productName = ulib.getProductName(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
g expiresAt = ulib.getExpirationDate(productId, licenseKey);
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
oductId, licenseKey)) {
            licenseValid = true;
            
            // Get detailed license information
            String discordId = ulib.getDiscordId(productId, licenseKey);
            String productName = ulib.getProductName(productId, licenseKey);
            String expiresAt = ulib.getExpirationDate(productId, licenseKey);
            String licenseStatus = ulib.getLicenseStatus(productId, licenseKey);
            
            // Display license information
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.DARK_AQUA + "✓ Authentication successful. Powering up Kraken..."
            );
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.GRAY + " » Discord ID: " + ChatColor.AQUA + discordId
            );
            
            // Continue loading your plugin...
            loadPlugin();
            
        } else {
            String lastError = ulib.getLastError();
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.RED + "✗ License authentication failed: " + lastError
            );
            
            if (lastError != null && lastError.contains("Unable to connect to the backend server")) {
                Bukkit.getConsoleSender().sendMessage(
                    ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                    ChatColor.YELLOW + "⚠ Retrying connection in 30 seconds..."
                );
                
                try {
                    Thread.sleep(30000);
                } catch (InterruptedException e) {
                    Bukkit.getPluginManager().disablePlugin(this);
                    return;
                }
            } else {
                Bukkit.getPluginManager().disablePlugin(this);
                return;
            }
        }
    }
}

3. Periodic Security Checks

private void startSecurityChecks() {
    ScheduledExecutorService licenseService = Executors.newSingleThreadScheduledExecutor();
    
    licenseService.scheduleAtFixedRate(() -> {
        UlisesLib ulib = new UlisesLib();
        String productId = antileakConfig.getString("license.product-id", "");
        String licenseKey = antileakConfig.getString("license.key", "");
        
        if (!ulib.isLicenseValid(productId, licenseKey)) {
            String lastError = ulib.getLastError();
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.RED + "✗ License validation failed during periodic check."
            );
            
            if (lastError != null && lastError.contains("Unable to connect to the backend server")) {
                Bukkit.getConsoleSender().sendMessage(
                    ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                    ChatColor.YELLOW + "⚠ Will retry in next check cycle..."
                );
            } else {
                Bukkit.getScheduler().runTask(this, () -> Bukkit.getPluginManager().disablePlugin(this));
                licenseService.shutdown();
            }
        } else {
            // Display successful check with details
            Bukkit.getConsoleSender().sendMessage(
                ChatColor.GRAY + "[" + ChatColor.DARK_AQUA + "Kraken" + ChatColor.GRAY + "] " +
                ChatColor.GREEN + "✓ License check passed. Status: " + 
                ulib.getLicenseStatus(productId, licenseKey)
            );
        }
    }, 10L, 10L, TimeUnit.MINUTES);
}

Complete Plugin Example

public class KrakenAntiCheat extends JavaPlugin {
    private FileConfiguration antileakConfig;
    
    @Override
    public void onEnable() {
        loadAntileakConfig();
        
        String productId = antileakConfig.getString("license.product-id");
        String licenseKey = antileakConfig.getString("license.key");
        
        if (productId.equals("your-product-id-here") || licenseKey.equals("your-license-key-here")) {
            getLogger().severe("License details not configured. Please edit antileak.yml");
            Bukkit.getPluginManager().disablePlugin(this);
            return;
        }
        
        validateLicense(productId, licenseKey);
    }
    
    private void validateLicense(String productId, String licenseKey) {
        UlisesLib ulib = new UlisesLib();
        
        while (true) {
            if (ulib.isLicenseValid(productId, licenseKey)) {
                // License is valid - continue loading plugin
                String discordId = ulib.getDiscordId(productId, licenseKey);
                String expiresAt = ulib.getExpirationDate(productId, licenseKey);
                
                getLogger().info("License validated for Discord ID: " + discordId);
                getLogger().info("License expires: " + expiresAt);
                
                // Load your plugin features
                loadFeatures();
                startPeriodicChecks();
                break;
                
            } else {
                String error = ulib.getLastError();
                getLogger().severe("License validation failed: " + error);
                
                if (error != null && error.contains("Unable to connect to the backend server")) {
                    getLogger().warning("Retrying connection in 30 seconds...");
                    try {
                        Thread.sleep(30000);
                    } catch (InterruptedException e) {
                        Bukkit.getPluginManager().disablePlugin(this);
                        break;
                    }
                } else {
                    Bukkit.getPluginManager().disablePlugin(this);
                    break;
                }
            }
        }
    }
    
    private void startPeriodicChecks() {
        Bukkit.getScheduler().runTaskTimerAsynchronously(this, () -> {
            UlisesLib ulib = new UlisesLib();
            String productId = antileakConfig.getString("license.product-id");
            String licenseKey = antileakConfig.getString("license.key");
            
            if (!ulib.isLicenseValid(productId, licenseKey)) {
                String error = ulib.getLastError();
                getLogger().severe("Periodic license check failed: " + error);
                
                if (!error.contains("Unable to connect to the backend server")) {
                    Bukkit.getScheduler().runTask(this, () -> 
                        Bukkit.getPluginManager().disablePlugin(this)
                    );
                }
            } else {
                getLogger().info("Periodic license check passed.");
            }
        }, 20L * 60 * 10, 20L * 60 * 10); // Every 10 minutes
    }
}

Enhanced API Methods

String getDiscordId(String productId, String licenseKey)

Retrieves the Discord ID associated with the license. Returns null if validation fails.

String discordId = ulib.getDiscordId(productId, licenseKey);
// Returns: "1216532655592439862"

String getProductName(String productId, String licenseKey)

Retrieves the product name from the license. Returns null if validation fails.

String productName = ulib.getProductName(productId, licenseKey);
// Returns: "KrakenAnticheat"

String getExpirationDate(String productId, String licenseKey)

Retrieves the expiration date in ISO format. Returns null if validation fails.

String expiresAt = ulib.getExpirationDate(productId, licenseKey);
// Returns: "2025-12-05T00:00:00.000Z"

String getLicenseStatus(String productId, String licenseKey)

Retrieves the license status (active/revoked/expired). Returns null if validation fails.

String status = ulib.getLicenseStatus(productId, licenseKey);
// Returns: "active"

String getSubType(String productId, String licenseKey)

Retrieves the license subtype (Enterprise, Advanced, etc). Returns null if validation fails.

String subType = ulib.getSubType(productId, licenseKey);
// Returns: "Enterprise"

String getLastError()

Returns the last error message. Useful for debugging connection issues.

Connection Management

Automatic Reconnection

The library now handles connection issues automatically

Infinite Retry: When backend is unreachable, the library retries every 30 seconds until successful

Clear Messages: Console shows "Unable to connect to the backend server" with retry countdown

Graceful Handling: Only disables plugin for actual license issues, not connection problems

Important Note for Plugin Developers

Auto-Update Integration

boolean checkForUpdate(String productId, String licenseKey, String currentVersion)

Checks if a newer version of the product jar is available. Returns true if an update exists.

String currentVersion = "1.0.0";
if (ulib.checkForUpdate(productId, licenseKey, currentVersion)) {
    getLogger().info("Update available! Downloading...");
    ulib.downloadUpdate(productId, licenseKey, hwid);
}

File downloadUpdate(String productId, String licenseKey, String hwid)

Downloads the latest jar file. Automatically handles HWID binding on first download. Returns the downloaded File, or null if download fails.

String hwid = ulib._getHwid();
File updatedJar = ulib.downloadUpdate(productId, licenseKey, hwid);
if (updatedJar != null) {
    getLogger().info("Update downloaded: " + updatedJar.getName());
    // Optionally verify checksum
    if (ulib.verifyChecksum(productId, licenseKey, hwid, updatedJar)) {
        getLogger().info("Checksum verified!");
    }
}

boolean verifyChecksum(String productId, String licenseKey, String hwid, File jarFile)

Verifies the SHA-256 checksum of the downloaded jar file to ensure file integrity.

File jarFile = new File("plugins/MyPlugin.jar");
boolean valid = ulib.verifyChecksum(productId, licenseKey, hwid, jarFile);
if (!valid) {
    getLogger().warning("Checksum mismatch! File may be corrupted.");
}

String getCurrentVersion(String productId, String licenseKey)

Returns the latest version string of the product jar available on the server.

String latestVersion = ulib.getCurrentVersion(productId, licenseKey);
getLogger().info("Latest version available: " + latestVersion);

Security Validations

All update operations automatically validate:

License Status: Only active, non-expired licenses can download updates

HWID Binding: Hardware ID is validated and bound to the license on first download

IP Limit: Respects the IP limit configured per license

Complete Auto-Update Example

private void checkAndApplyUpdate(String productId, String licenseKey) {
    String currentVersion = this.getDescription().getVersion();
    String hwid = ulib.getHardwareId();

    // Check if update is available
    if (ulib.checkForUpdate(productId, licenseKey, currentVersion)) {
        String latestVersion = ulib.getCurrentVersion(productId, licenseKey);
        getLogger().info("New version available: " + latestVersion + " (current: " + currentVersion + ")");

        // Download the update
        File updatedJar = ulib.downloadUpdate(productId, licenseKey, hwid);
        if (updatedJar != null) {
            // Verify integrity
            if (ulib.verifyChecksum(productId, licenseKey, hwid, updatedJar)) {
                getLogger().info("Update downloaded and verified successfully!");
                getLogger().info("Restart the server to apply the update.");
            } else {
                getLogger().warning("Checksum verification failed. Update may be corrupted.");
            }
        }
    } else {
        getLogger().info("Plugin is up to date.");
    }
}

Best Practices

✓

Do This

Use infinite retry loops for connection issues
Display detailed license information on successful validation
Implement periodic checks (every 10 minutes)
Create configuration file with default values

✗

Avoid This

Disabling plugin on connection timeout
Hardcoding credentials in source code
Exposing error details to end users
Running validation on main thread