組合模式:允許你將對象組合成樹形結構來表現“整體/部分”層次結構。組合能讓客戶以一致的方式處理個別對象以及對象組合。
組合模式類圖: Client:客戶使用Component接口操作組合中的對象。 Component:Component為組合中的所有對象定義一個接口,不管是組合還是節點,Component可以為add(),remove(),eachChild()實現一些默認的行為。 Leaf:葉節點沒有孩子。葉節點通過實現Composite支持的操作,定義了組合內元素的行為。 Composite:Composite的角色是要定義組件的行為,而這樣的組件具有子節點。
抽象類Component代碼實現:
public abstract class Component { String name; public Component(String name){ this.name = name; } public abstract void Add(Component component); public abstract void remove(Component component); public abstract void eachChild();}Leaf類代碼實現:
public class Leaf extends Component{ public Leaf(String name) { super(name); // TODO Auto-generated constructor stub } @Override public void Add(Component component) { // TODO Auto-generated method stub } @Override public void remove(Component component) { // TODO Auto-generated method stub } @Override public void eachChild() { // TODO Auto-generated method stub System.out.Composite類代碼實現:public class Composite extends Component{ ArrayList<Component> list = new ArrayList<Component>(); public Composite(String name) { super(name); // TODO Auto-generated constructor stub } @Override public void Add(Component component) { // TODO Auto-generated method stub list.add(component); } @Override public void remove(Component component) { // TODO Auto-generated method stub list.remove(component); } @Override public void eachChild() { // TODO Auto-generated method stub System.out.println("節點:"+name); for(Component component : list){ component.eachChild(); } }}Client類代碼實現:
public class Client { public static void main(String[] args){ Component rootComposite = new Composite("根節點"); Component leftComposite = new Composite("左子節點"); Component rightComposite = new Composite("右子節點"); Component leftleaf1 = new Leaf("左葉節點1"); Component leftleaf2 = new Leaf("左葉節點2"); leftComposite.Add(leftleaf1); leftComposite.Add(leftleaf2); rootComposite.Add(leftComposite); rootComposite.Add(rightComposite); rootComposite.eachChild(); }}運行結果:
節點:根節點節點:左子節點葉節點:左葉節點1葉節點:左葉節點2節點:右子節點新聞熱點
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