shutodwn hook

core/src/main/java/mc/core/Main.java

@@ -33,6 +33,7 @@ public class Main {
         gameLoop.start();
 
         Server server = appContext.getBean("server", Server.class);
+        Runtime.getRuntime().addShutdownHook(new Thread(server::stop));
         try {
             server.start();
         } catch (StartServerException e) {

core/src/main/java/mc/core/network/Server.java

@@ -6,4 +6,5 @@ package mc.core.network;
 
 public interface Server {
     void start() throws StartServerException;
+    void stop();
 }

proto125_netty/src/main/java/mc/core/network/proto_125/netty/NettyServer.java

@@ -72,4 +72,11 @@ public class NettyServer implements Server {
             throw new StartServerException(e);
         }
     }
+
+    @Override
+    public void stop() {
+        log.info("Server shutdown");
+        workerGroup.shutdownGracefully();
+        bossGroup.shutdownGracefully();
+    }
 }