组合模式

组合模式：将对象组合成树形结构以表示"部分-整体"的层次结构。"Composite使得用户对单个对象和组合对象的使用具有一致性。"

public abstract class AComponent {

protected String name;

public AComponent(String name){

System.out.println(name);

}

abstract public void Add(AComponent c); //添加结点

abstract public void Remove(AComponent c); //移除结点

abstract public void Display(int i); //输出结点结构

}

 

//组合类 

public class Composite extends AComponent{

static AComponent component;

private ArrayList children = new ArrayList();

public Composite(String name) {

super(name);  }

public void Add(AComponent c) {

this.component = c; children.add(c); }

public void Remove(AComponent c) {

children.remove(c); }

public void Display(int i) {

Iterator iter = children.iterator();

AComponent c = null;

c = (AComponent) iter.next();

while(iter.hasNext()&&iter.next().equals(null))

{ System.out.println("abc------"+c.name); } } }

 

//单对象类

public class Leaf extends AComponent{  

public Leaf(String name) {

super(name); }

public void Add(AComponent c) {

System.out.println("不能添加子项!"); }

public void Remove(AComponent c) {

System.out.println("不能移除子项!"); }

public void Display(int i) {

System.out.println("abc"+new String()+name); } }

 

//测试类 

public class Test {

public static void main(String[] args) {

Composite root = new Composite("根目录");

root.Add(new Leaf("---子项A"));

root.Add(new Leaf("---子项B"));

Composite comp = new Composite("组合X");

comp.Add(new Leaf("---子项XA"));

comp.Add(new Leaf("---子项XB"));

root.Add(comp);

root.Add(new Leaf("---子项C"));

Leaf l = new Leaf("---子项D");

root.Add(l);

root.Remove(l);

root.Display(2);

}

}