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Overview

The GameServer class is the main entry point and initialization engine for the L2J Mobius Chronicle 4 game server. It orchestrates the complete server startup sequence, initializing all subsystems in the correct order. Package: org.l2jmobius.gameserver Location: GameServer.java:158

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Class Signature

public class GameServer

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Constructor

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GameServer()

public GameServer() throws Exception
Initializes the game server and all its subsystems. This constructor performs the complete server bootstrap sequence. Throws: Exception - if any critical initialization step fails

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Initialization Sequence

The GameServer follows a carefully orchestrated initialization sequence:

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1. Logging Configuration

final File logFolder = new File(".", "log");
logFolder.mkdir();

try (InputStream is = new FileInputStream(new File("./log.cfg")))
{
    LogManager.getLogManager().readConfiguration(is);
}
Creates the log directory and configures the logging system from log.cfg.

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2. GUI Initialization (Optional)

InterfaceConfig.load();
if (InterfaceConfig.ENABLE_GUI)
{
    LOGGER.info("GameServer: Running in GUI mode.");
    new Gui();
}
If enabled in configuration, starts the graphical user interface for server monitoring.

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3. Core Systems

Initialized in this order:
1

Configuration

Loads all server configuration files via ConfigLoader.init()
2

Database

Initializes the HikariCP connection pool via DatabaseFactory.init()
3

Thread Pool

Starts the managed thread pool for asynchronous operations
4

Game Time

Starts the in-game time manager early for time-dependent systems
5

ID Manager

Initializes object ID generation and tracking

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4. Scripting Engine

EventDispatcher.getInstance();
ScriptEngine.getInstance();
Starts the scripting engine for AI, quests, and custom functionality.

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5. World Systems

InstanceManager.getInstance();
World.getInstance();
MapRegionManager.getInstance();
AnnouncementsTable.getInstance();
GlobalVariablesManager.getInstance();
Initializes the game world, instance management, and map regions.

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6. Game Data

Loads game data in sections:
  • Skills: Effect handlers, skill trees, pet skills
  • Items: Item templates, enchant data, armor sets, fishing, recipes
  • Characters: Classes, templates, experience tables, clans
  • NPCs: NPC templates, doors, zones, spawns, teleporters
  • Olympiad: Hero system and olympiad competitions
  • Seven Signs: Seven Signs event system

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7. Scripts and Spawns

LOGGER.info("Loading server scripts...");
ScriptEngine.getInstance().executeScript(ScriptEngine.MASTER_HANDLER_FILE);
ScriptEngine.getInstance().executeScriptList();

SpawnData.getInstance();
DayNightSpawnManager.getInstance().trim().notifyChangeMode();
Executes all server scripts and spawns NPCs/monsters into the world.

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8. Network Layer

new ConnectionManager<>(
    new InetSocketAddress(ServerConfig.PORT_GAME), 
    GameClient::new, 
    new GamePacketHandler()
);

LoginServerThread.getInstance().start();
Starts the network connection manager on the configured game port and establishes connection to the login server. See: ConnectionManager, GameClient

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9. Final Steps

  • Restores offline traders and auto-play characters
  • Starts server restart scheduler (if enabled)
  • Starts deadlock detection watchdog (if enabled)
  • Plays system beep to indicate successful startup

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Static Methods

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getStartTime()

public static long getStartTime()
Returns the server start timestamp in milliseconds.
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returns
long
The system time in milliseconds when the server was started

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main()

public static void main(String[] args) throws Exception
The application entry point. Creates a new GameServer instance.
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args
String[]
Command line arguments (currently unused)

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Instance Methods

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getUsedMemoryMB()

public long getUsedMemoryMB()
Calculates the current memory usage in megabytes.
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returns
long
The amount of memory currently in use by the JVM in megabytes
Implementation: 
return (Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory()) / 1048576;

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Usage Example

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Starting the Server

public static void main(String[] args) throws Exception
{
    new GameServer();
}
The constructor handles all initialization. The server will log its progress through each initialization phase.

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Typical Startup Log Output

--------------------------=[ Database ]
Database: HikariCP pool initialized successfully.
--------------------------=[ ThreadPool ]
--------------------------=[ IdManager ]
--------------------------=[ Scripting Engine ]
--------------------------=[ World ]
--------------------------=[ Skills ]
--------------------------=[ Items ]
--------------------------=[ Characters ]
...
GameServer: Started, using 512 of 4096 MB total memory.
GameServer: Maximum number of connected players is 2000.
GameServer: Server loaded in 47 seconds.

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Configuration Dependencies

The GameServer relies on these configuration classes:
  • InterfaceConfig - GUI settings
  • ServerConfig - Server ports, restart schedules, deadlock detection
  • GeneralConfig - General game settings
  • DatabaseConfig - Database connection settings (via DatabaseFactory)
See: DatabaseFactory

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Shutdown Handling

Runtime.getRuntime().addShutdownHook(Shutdown.getInstance());
Registers a shutdown hook to ensure graceful server shutdown when the JVM exits.

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Performance Monitoring

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Memory Statistics

The server logs memory usage on startup: 
final long totalMem = Runtime.getRuntime().maxMemory() / 1048576;
LOGGER.info(getClass().getSimpleName() + ": Started, using " + getUsedMemoryMB() + " of " + totalMem + " MB total memory.");

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Deadlock Detection

If enabled, starts a watchdog thread to detect and optionally recover from deadlocks: 
if (ServerConfig.DEADLOCK_WATCHER)
{
    final DeadlockWatcher deadlockWatcher = new DeadlockWatcher(
        Duration.ofSeconds(ServerConfig.DEADLOCK_CHECK_INTERVAL), 
        () ->
        {
            if (ServerConfig.RESTART_ON_DEADLOCK)
            {
                Broadcast.toAllOnlinePlayers("Server has stability issues - restarting now.");
                Shutdown.getInstance().startShutdown(null, 60, true);
            }
        }
    );
    deadlockWatcher.setDaemon(true);
    deadlockWatcher.start();
}

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Notes

The initialization order is critical. Changing the sequence can cause initialization failures due to dependencies between subsystems.
The GameServer constructor blocks until initialization is complete. On a typical system, this takes 30-60 seconds depending on data size and database performance.
  • DatabaseFactory - Database connection pooling
  • ConnectionManager - Network connection management
  • GameClient - Client connection handling
  • Shutdown - Graceful server shutdown
  • ThreadPool - Managed thread pool for async operations

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