【Java代码】 import Java.util.ArrayList import java.util.List （1） class AbstractFile｛ protected String name public void printName()｛System.out.println(name)｝ public abstract boolean addChild(AbstractFile file) public abstract boolean removeChild(AbstractF ile file) public abstract List getChildren() ｝ class File extends AbstractFile｛ public File(String name）｛this.name＝name｝ public boolean addChild(AbstractFile file)｛return false｝ public boolean removeChild(AbstractFile file)｛return false｝ public List getChildren()｛return （2） ｝ ｝ class Folder extends AbstractFile｛ private List childList public Folder(String name)｛ this.name＝name this.childList＝new ArrayList () ｝ public boolean addChild(AbstractFile file) { return childList．add(file)｝ public boolean removeChild(AbstractFile file)｛return childList．remove(file)｝ public （3） getChildren()｛return （4） ｝ ｝ public class Client｛ public static void main(String[] args)｛ //构造一个树形的文件／目录结构 AbstractFile rootFolder＝ new Folder('c:// ') AbstractFile compositeFolder＝new Folder('composite') AbstractFile windowsFolder＝new Folder('windows') AbstractFile file＝new File('TestComposite.java') rootFolder.addChild(compositeFolder) rootFolder.addChild(windowsFolder) compositeFolder.addChild(file) //打印目录文件树 printTree(rootFolder) ｝ private static void printTree(AbslractFile ifile)｛ ifile.printName() List children＝ifile．getChildreno： if(children==null) return for (AbstractFile file:children) { （5） ｝ } ｝ 该程序运行后输出结果为： c:/ composite TestComposite.java Windows