这是一个加载的问题。
如果它纯粹是关于布局，那么我会使用一系列具有自己布局的复合组件来实现您需要的结果......
如果是关于方法，那么它会变得更加复杂......
基本上，您希望划分职责范围。
从问题来看，有两种不同的模型，电梯模型和建筑模型。
电梯模型控制单个竖井的电梯所在的位置，因为建筑模型控制诸如楼层数、单个电梯模型、确定电梯如何被呼叫到楼层的算法……
以下是一个想法的基本示例。它缺少（除其他外）将电梯呼叫到楼层所需的逻辑或有关电梯的状态信息（移动、等待、打开......）
public class Elevator {
public static void main(String[] args) {
new Elevator();
}
public Elevator() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new BuildingPane());
frame.pack();
frame.setVisible(true);
}
});
}
public enum ElevatorShaft {
Left,
Right
}
public interface ElevatorModel {
public int getFloor();
public void setFloor(int floor);
public void addPropertyChangeListener(PropertyChangeListener listener);
public void removePropertyChangeListener(PropertyChangeListener listener);
}
public class DefaultElevatorModel implements ElevatorModel {
private int floor;
private PropertyChangeSupport propertyChangeSupport;
public DefaultElevatorModel(int floor) {
this.floor = floor;
propertyChangeSupport = new PropertyChangeSupport(this);
}
@Override
public void addPropertyChangeListener(PropertyChangeListener listener) {
propertyChangeSupport.addPropertyChangeListener(listener);
}
@Override
public void removePropertyChangeListener(PropertyChangeListener listener) {
propertyChangeSupport.removePropertyChangeListener(listener);
}
@Override
public int getFloor() {
return floor;
}
@Override
public void setFloor(int value) {
if (value != floor) {
int old = floor;
floor = value;
propertyChangeSupport.firePropertyChange("floor", old, floor);
}
}
}
public interface BuildingModel {
public int getFloorCount();
public int getFloor(ElevatorShaft shaft);
public ElevatorModel getElevatorModel(ElevatorShaft shaft);
public void call(int floor);
}
public class DefaultBuildingModel implements BuildingModel {
private int floorCount;
private Map<ElevatorShaft, ElevatorModel> shaftManager;
public DefaultBuildingModel(int floorCount) {
this.floorCount = floorCount;
shaftManager = new HashMap<ElevatorShaft, ElevatorModel>(2);
shaftManager.put(ElevatorShaft.Left, new DefaultElevatorModel((int)Math.round(Math.random() * (floorCount - 1))));
shaftManager.put(ElevatorShaft.Right, new DefaultElevatorModel((int)Math.round(Math.random() * (floorCount - 1))));
}
@Override
public ElevatorModel getElevatorModel(ElevatorShaft shaft) {
return shaftManager.get(shaft);
}
@Override
public int getFloorCount() {
return floorCount;
}
@Override
public int getFloor(ElevatorShaft shaft) {
return shaftManager.get(shaft).getFloor();
}
@Override
public void call(int floor) {
// This will need to determine which elevator should be called
// and call that elevators model "setFloor" method...
}
}
public class BuildingPane extends JPanel {
public BuildingPane() {
setLayout(new GridBagLayout());
BuildingModel model = new DefaultBuildingModel(3);
Shaft leftShaft = new Shaft(model, ElevatorShaft.Left);
Shaft rightShaft = new Shaft(model, ElevatorShaft.Right);
ButtonsPane buttonsPane = new ButtonsPane(model);
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.fill = GridBagConstraints.VERTICAL;
add(leftShaft, gbc);
gbc.gridx++;
add(buttonsPane, gbc);
gbc.gridx++;
add(rightShaft, gbc);
}
}
public class ButtonsPane extends JPanel {
private BuildingModel model;
public ButtonsPane(BuildingModel model) {
this.model = model;
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 0;
gbc.weighty = 1;
gbc.anchor = GridBagConstraints.CENTER;
int floorCount = model.getFloorCount();
ActionHandler handler = new ActionHandler();
for (int floor = floorCount; floor > 0; floor--) {
JButton button = new JButton("Floor " + floor);
button.setActionCommand(Integer.toString(floor));
button.addActionListener(handler);
add(button, gbc);
gbc.gridy++;
}
}
public BuildingModel getModel() {
return model;
}
public class ActionHandler implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
try {
int floor = Integer.parseInt(cmd);
getModel().call(floor);
} catch (NumberFormatException exp) {
exp.printStackTrace();
}
}
}
}
public class Shaft extends JPanel {
private BufferedImage elevator;
private BuildingModel buildingModel;
private ElevatorShaft shaft;
public Shaft(BuildingModel model, ElevatorShaft shaft) {
this.buildingModel = model;
this.shaft = shaft;
buildingModel.getElevatorModel(shaft).addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equalsIgnoreCase("floor")) {
// Need to update our position, this could
// be done via animation or directly call something
// like repaint..
}
}
});
setBorder(new LineBorder(Color.DARK_GRAY));
setBackground(Color.GRAY);
try {
elevator = ImageIO.read(new File("elevator.png"));
} catch (IOException ex) {
Logger.getLogger(Elevator.class.getName()).log(Level.SEVERE, null, ex);
}
}
public BuildingModel getBuildingModel() {
return buildingModel;
}
public ElevatorShaft getShaft() {
return shaft;
}
public int getFloorCount() {
return getBuildingModel().getFloorCount();
}
public int getFloor() {
return getBuildingModel().getFloor(getShaft());
}
@Override
public Dimension getPreferredSize() {
Dimension size = new Dimension(elevator.getWidth(), elevator.getHeight() * getFloorCount());
Insets insets = getInsets();
size.width += (insets.left + insets.right);
size.height += (insets.top + insets.bottom);
return size;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Insets insets = getInsets();
int x = insets.left;
int y = insets.top;
int height = getHeight() - (insets.top + insets.bottom);
int floor = getFloor();
y = height - (elevator.getHeight() * (floor + 1));
g.drawImage(elevator, x, y, this);
}
}
}