Shutdown about tdlight-java HOT 1 CLOSED

You must send TdApi.Close() and wait for the TdApi.Ok response.
If you want to make sure that tdlib is closed when the app is closed, you must send TdApi.Close() and wait for its response in a shutdown hook.

Runtime.getRuntime().addShutdownHook(new Thread() { 
  public void run() { 
    // Send here TdApi.Close(), and wait for TdApi.Ok response
  } 
}); 

from tdlight-java.