Java与模式：合成模式

import java.util.Vector;

/**
* Created by IntelliJ IDEA.
* User: leizhimin
* Date: 2008-8-2 16:15:03
* 文件夹角色
*/
public class Folder implements IFile {
    private String name;    //文件名字
    private int deep;       //层级深度，根深度为0
    private Vector componentVector = new Vector();

    public Folder(String name) {
        this.name = name;
    }

    //返回自己的实例
    public IFile getComposite() {
        return this;
    }

    //某个商业方法
    public void sampleOperation() {
        System.out.println("执行了某个商业方法！");
    }

    //增加一个文件或文件夹
    public void add(IFile IFile) {
        componentVector.addElement(IFile);
        IFile.setDeep(this.deep + 1);

    }

    //删除一个文件或文件夹
    public void remove(IFile IFile) {
        componentVector.removeElement(IFile);
    }

    //返回直接子文件（夹）集合
    public Vector getAllComponent() {
        return componentVector;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getDeep() {
        return deep;
    }

    public void setDeep(int deep) {
        this.deep = deep;
    }
}
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import java.util.Iterator;
import java.util.Vector;

/**
* Created by IntelliJ IDEA.
* User: leizhimin
* Date: 2008-8-2 16:35:25
* 遍历树的一个测试
*/
public class Client {
    public static String indentChar = "\t";       //文件层次缩进字符

    public static void main(String args[]) {
        new Client().test();
    }

    /**
     * 客户端测试方法
     */
    public void test() {
        //根下文件及文件夹
        Folder root = new Folder("树根");

        Folder b1_1 = new Folder("1_枝1");
        Folder b1_2 = new Folder("1_枝2");
        Folder b1_3 = new Folder("1_枝3");
        File l1_1 = new File("1_叶1");
        File l1_2 = new File("1_叶2");
        File l1_3 = new File("1_叶3");

        //b1_2下的文件及文件夹
        Folder b2_1 = new Folder("2_枝1");
        Folder b2_2 = new Folder("2_枝2");
        File l2_1 = new File("2_叶1");

        //缔造树的层次关系（简单测试，没有重复添加的控制）
        root.add(b1_1);
        root.add(b1_2);
        root.add(l1_1);
        root.add(l1_2);

        b1_2.add(b2_1);
        b1_2.add(b2_2);
        b1_2.add(l2_1);
        root.add(l1_3);
        root.add(b1_3);
        //控制台打印树的层次
        outTree(root);
    }

    public void outTree(Folder folder) {
        System.out.println(folder.getName());
        iterateTree(folder);
    }

    /**
     * 遍历文件夹，输入文件树
     *
     * @param folder
     */
    public void iterateTree(Folder folder) {
        Vector clist = folder.getAllComponent();
        //todo:遍历之前可以对clist进行排序，这些都不是重点
        for (Iterator it = clist.iterator(); it.hasNext();) {
            IFile em = it.next();
            if (em instanceof Folder) {
                Folder cm = (Folder) em;
                System.out.println(getIndents(em.getDeep()) + cm.getName());
                iterateTree(cm);
            } else {
                System.out.println(getIndents(em.getDeep()) + ((File) em).getName());
            }
        }
    }

    /**
     * 文件层次缩进字符串
     *
     * @param x 缩进字符个数
     * @return 缩进字符串
     */
    public static String getIndents(int x) {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < x; i++) {
            sb.append(indentChar);
        }
        return sb.toString();
    }
}
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