example

public class MyPlugin extends JavaPlugin {
     private MyManager myManager;

     @Override
     public void onEnable() {
          this.myManager = new MyManager();
          registerListener(new MyListener(this));
     }

     public MyManager getMyManager() {
          return this.myManager;
     }
}

public class MyListener {

     private final MyPlugin myPlugin;

     public MyListener(MyPlugin myPlugin) {
          this.myPlugin = myPlugin;
     }

     @EventHandler
     public void on(BlockBreakEvent event) {
          this.myPlugin.getMyManager().incrementCount(event.getPlayer());
     }
}