设计模式＝＝组合模式（Composite）
/* * * 组合模式（Composite） * * * 把整体和局部的关系用树状结构描述出来，使得客户端把整体对象和局部对象同等看待。 */package model;import java.util.*;public class TestComposite { public static void main(String[] args) { Node n1 = new LeafNode(3); Node n2 = new LeafNode(4); Node n3 = new LeafNode(6); Node n4 = new LeafNode(5); Node n5 = new LeafNode(2); Node n6 = new LeafNode(9); Node n7 = new LeafNode(12); Node n8 = new LeafNode(7); Node n9 = new LeafNode(8); Node c1 = new CompositeNode(n1, n2, n3); Node c4 = new CompositeNode(n8, n9); Node c3 = new CompositeNode(n5, c4); Node c2 = new CompositeNode(n4, c3); Node c5 = new CompositeNode(n6, n7); Node root = new CompositeNode(c1, c2, c5); System.out.println(root.getValue()); }}abstract class Node { public abstract int getValue();}class LeafNode extends Node { int value; public LeafNode(int value) { this.value = value; } public int getValue() { return value; }}class CompositeNode extends Node { private List<Node> children = new ArrayList<Node>(); public CompositeNode(Node... nodes) { for (Node n : nodes) { children.add(n); } } public int getValue() { int result = 0; for (Node n : children) { result += n.getValue(); } return result; }}?