设计模式6：Composite

Entry.java:

package gendwang.cisco.com;

public abstract class Entry
{
	private int height = 0;
	private String name;
	private Type type;

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

	public int getHeight() {
		return height;
	}

	public void setHeight(int height) {
		this.height = height;
	}

	public String getName() {
		return name;
	}

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

	public Type getType() {
		return type;
	}

	public void setType(Type type) {
		this.type = type;
	}

	public abstract void print();
}

File.java:

package gendwang.cisco.com;

public class File extends Entry
{
	public File(String name)
	{
		super(name);
		setType(Type.File);
	}

	public void print()
	{
		int numOfWhiteSpace = getHeight() * 2;
		for(int i = 0; i < numOfWhiteSpace; i++)
		{
			System.out.print(" ");
		}

		System.out.println(getName());
	}
}

Directory.java:

package gendwang.cisco.com;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

public class Directory extends Entry
{
	private List<Entry> list = new LinkedList<Entry>();

	public Directory(String name)
	{
		super(name);
		setType(Type.Directory);
	}

	public void addEntry(Entry entry)
	{
		int myHeight = getHeight();
		incrementHeight(entry, myHeight + 1);

		list.add(entry);
	}

	public List<Entry> getChilden()
	{
		return list;
	}

	public void print()
	{
		int numOfWhiteSpace = getHeight() * 2;
		for(int i = 0; i < numOfWhiteSpace; i++)
		{
			System.out.print(" ");
		}
		System.out.println(getName());

		Iterator<Entry> itor = list.iterator();
		while(itor.hasNext())
		{
			Entry entry = itor.next();
			entry.print();
		}
	}

	private void incrementHeight(Entry entry, int added)
	{
		int height = entry.getHeight();
		entry.setHeight(height + added);

		if(entry.getType() == Type.Directory)
		{
			Directory dir = (Directory)entry;
			List<Entry> list = dir.getChilden();
			Iterator<Entry> itor = list.iterator();
			while(itor.hasNext())
			{
				Entry tmp = itor.next();
				incrementHeight(tmp, added);
			}
		}
	}
}

Type.java:

package gendwang.cisco.com;

public enum Type
{
	File,
	Directory
}

Test.java:

package gendwang.cisco.com;

public class Test
{
	public static void main(String[] args)
	{
		Directory dir1 = new Directory("tmp");
		Entry file1 = new File("hello.jpg");
		Entry file2 = new File("install.log");
		dir1.addEntry(file1);
		dir1.addEntry(file2);

		Directory dir2 = new Directory("system");

		Directory dir3 = new Directory("windows");
		dir3.addEntry(dir1);
		dir3.addEntry(dir2);

		Directory dir4 = new Directory("root");
		Entry file3 = new File("password");
		dir4.addEntry(file3);
		dir4.addEntry(dir3);

		dir4.print();
	}
}