实验10：组合模式

本次实验属于模仿型实验，通过本次实验学生将掌握以下内容：

1、理解组合模式的动机，掌握该模式的结构；

2、能够利用组合模式解决实际问题。

[实验任务一]：组合模式

用透明组合模式实现教材中的“文件夹浏览”这个例子。

实验要求：

1. 类图如下

2. 源代码以及相关截图；

运行截图

源代码

package a10;  
public abstract class AbstractFile  
{  
public abstract void add(AbstractFile element);  
public abstract void remove(AbstractFile element);  
public abstract void display();  
}  
 

package a10;  
import java.util.*;  
public class Folder extends AbstractFile  
{  
private String fileName;  
private ArrayList<AbstractFile> fileList=new ArrayList();  
public Folder(String filename)  
{  
this.fileName=new String();  
this.fileName=filename;  
}  
public void add(AbstractFile element)  
{  
fileList.add(element);  
System.out.println("add Folder");  
}  
public void remove(AbstractFile element)  
{  
fileList.remove(element);  
System.out.println("remove Folder");  
}  
public void display()  
{  
System.out.println(fileName);  
for(Object object:fileList)  
{  
((AbstractFile)object).display();  
}  
System.out.println("****Folder display****");  
}  
}  
package a10;  
public class ImageFile extends AbstractFile  
{  
private String fileName;  
public ImageFile(String filename)  
{  
this.fileName=new String();  
this.fileName=filename;  
}  
public void add(AbstractFile element)  
{  
System.out.println("add ImageFile");  
}  
public void remove(AbstractFile element)  
{  
System.out.println("remove ImageFile");  
}  
public void display()  
{  
System.out.print(fileName);  
System.out.println(" ImageFile");  
}  
}  
package a10;  
public class TextFile extends AbstractFile  
{  
private String fileName;  
public TextFile(String filename)  
{  
this.fileName=new String();  
this.fileName=filename;  
}  
public void add(AbstractFile element)  
{  
System.out.println("add TextFile");  
}  
public void remove(AbstractFile element)  
{  
System.out.println("remove TextFile");  
}  
public void display()  
{  
System.out.print(fileName);  
System.out.println(" TextFile");  
}  
}  
package a10;  
public class VideoFile extends AbstractFile  
{  
private String fileName;  
public VideoFile(String filename)  
{  
this.fileName=new String();  
this.fileName=filename;  
}  
public void add(AbstractFile element)  
{  
System.out.println("add VideoFile");  
}  
public void remove(AbstractFile element)  
{  
System.out.println("remove VideoFile");  
}  
public void display()  
{  
System.out.print(fileName);  
System.out.println(" VideoFile");  
}  
}  
package a10;  
public class Client  
{  
public static void main(String a[])  
{  
AbstractFile obj1,obj2,obj3,obj4;  
Folder plate1,plate2,plate3;  
obj1=new ImageFile("a.jpg");  
obj2=new TextFile("b.txt");  
plate1=new Folder("Image_Text");  
plate1.add(obj1);  
plate1.add(obj2);  
obj3=new VideoFile("c.mp4");  
plate2=new Folder("Image_Video");  
plate2.add(obj1);  
plate2.add(obj3);  
obj4=new ImageFile("d.jpg");  
plate3=new Folder("Image_Text_Video_Folder");  
plate3.add(plate1);  
plate3.add(plate2);  
plate3.add(obj4);  
plate3.display();  
}