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;    }}