[java] Global methods in Java?

//SomeClass.javapublic final SomeClass {    private static int value = 0;    public static void setValue(int param) {        value = param;    }    public static int getValue() {        }//OtherClass.javaSomeClass.setValue(5);int b = SomeClass.getValue();

public class MyGlobals {    public static Vector<Object> objects; //All classes in Java inherit from Object, primitive types however would have to be wrapped in Classes like Integer, Float etc)}//you can then store anything in that list by doing for example:SomeClass instance = new SomeClass(54,23);MyGlobals.objects.add(instance);

public class MyFrame extends JFrame {    private someObject = null;    public MyFrame(SomeObject stuff) {        someObject = stuff;    }}

SomeObject something = new SomeObject();JFrame f = new MyFrame(something);

interface TradeRouteListener{  public void tradeRouteAdded( TradeRouteEvent event );  public void tradeRouteRemoved( TradeRouteEvent event );}class TradeRouteManager{  public void addTradeRouteListener( TradeRouteListener listener );  public void removeTradeRouteListener( TradeRouteListener listener );}

class TradeRouteEvent{  public TradeRouteManager source;  public Entity routeStart;  public Entity routeEnd;  ....}

class TradeRouteGui extends JForm implements TradeRouteListener{  public void tradeRouteAdded( TradeRouteEvent event )  {    // routeList is your GUI component that displays names of the routs    routeList.add( event.routeStart.getName().toString() + event.routeStart.getName().toString());  }  public void tradeRouteRemoved( TradeRouteEvent event )  {    // When a route is removed, clear it from GUI as well    routeList.remove( event.routeStart.getName().toString() + event.routeStart.getName().toString());  }  TradeRouteGui( TradeRouteManager manager )  {    routeManager = manager;    routeManager.addTradeRouteListener( this );  }  private TradeRouteManager routeManager;  ....  // when something happens in GUI, you can now manipulate the routes  void onAddRouteButtonClicked( ... ) {    routeManager.addRoute( new Route( ) );  }}The obvious problem now is, how does RouteManagerGUI know about entities, clans, etc..., when all it has is the RouteManager.Here the design of the game becomes important, so there is no general answer.One is to make your Entity, clan, ... managers statically accessible. This is bad since if will lock you into design. If you ever want to change something, you'll affect your entire codebase.Another is to define basic component hierarchy.interface GameSystem{  public String getName();  GameSystem getParent();}class AbstractGameSystem implements GameSystem{  public AbstractGameSystem( String systemName, GameSystem sparent )  {    name = systemName;    parent = sparent;  }  public String getName()  {    return name;  }  public GameSystem getParent()  {    return parent;  }  private GameSystem parent;  private String name;}interface TradeRouteSystem extends GameSystem{  public static final String TRADE_SYS_NAME = "TradeSystem";  ... getTradeRoutes() ...  ... addTradeRoute() ...  ... removeTradeRoute() ...  ... addTradeRouteListener() ...  ... removeTradeRouteListener() ...}class TradeRouteManager extends AbstractGameSystem implements TradeRouteSystem{  public  TradeRouteManager( GameSystem game )  {    super( TradeRouteSystem.TRADE_SYS_NAME, sparent );  }  // rest of the logic implementation}

class GameSystems extends AbstractGameSystem{  GameSystems( )  {    // no parent, this is the core game    super("Game", null);    systems = new HashMap();  }  void addSystem( GameSystem sys )  {    systems.put( sys.getName(), sys );  }  GameSystem findByName( String name )  {    return (GameSystem)systems.get( name );  }  private HashMap systems;}

// When you start your gameGameSystems game = new GameSystems();game.addSystem( new TradeRouteManager( game ) );...game.addSystem( new ClanManager( game ) );game.addSystem( new EntityManager( game ) );...

class TradeRouteGui extends JForm implements TradeRouteListener{  // The rest remains the same  ....  // when something happens in GUI, you can now manipulate the routes  void onAddRouteButtonClicked( ... ) {    // Now we can get access to other systems        GameSystems gs = (GameSystems)routeManager.getParent();    ClanManager cm = (ClanManager)gs.findByName( ClanManager.CLAN_SYS_NAME );    EntityManager em = (EntityManager)gs.findByName( ClanManager.CLAN_SYS_NAME );    Entity routeStart = em... // find the entity you want    Entity routeEnd = em... // find the entity you want    // create new route    routeManager.addRoute( new Route( routeStart, routeEnd ) );  }}

MainFrame() {   super("Main Game Frame");   //... other initialization code   clanForm.getAddButton().addActionListener(        new ActionListener() {          public void actionPerformed( ActionEvent e ) {             Clan c = new Clan();             c.setName( clanForm.getClanNameComponent().getText() );             c.setMemberList( clanForm.getMemberList() );             clanList.add(c);          }       });   //... other initialization code   //you can do the same for all the components that modifies   //objects in the mainframe.}

public final class Game {   private static final Game myGameSingleton = new Game();   //this is where you could keep all your entity objects   private ArrayList<Entity> entities = new ArrayList<Entity>();   //and your routes   private MasterTradeRouteList routeList = new MasterTradeRouteList();   protected Game() {   }     /// Main method for accessing the one and only instance.   /// It is globally accessible.   public static Game getGameSingleton() {return myGameSingleton;}   //then you would have your accessors and adding, modifying, removing methods   public void addEntity( Entity e ) {entities.add(e);)   //etc...}