当前页面: 开发资料首页 → Java 专题 → java设计模式之Composite(组合)
摘要: java设计模式之Composite(组合)
public abstract class Equipment
{
private String name;
//实价
public abstract double netPrice();
//折扣价格
public abstract double discountPrice();
//增加部件方法
public boolean add(Equipment equipment) { return false; }
//删除部件方法
public boolean remove(Equipment equipment) { return false; }
//注意这里,这里就提供一种用于访问组合体类的部件方法。
public Iterator iter() { return null; }
public Equipment(final String name) { this.name=name; }
}
public class Disk extends Equipment
{
public Disk(String name) { super(name); }
//定义Disk实价为1
public double netPrice() { return 1.; }
//定义了disk折扣价格是0.5 对折。
public double discountPrice() { return .5; }
}
abstract class CompositeEquipment extends Equipment
{
private int i=0;
//定义一个Vector 用来存放'儿子'
private Lsit equipment=new ArrayList();
public CompositeEquipment(String name) { super(name); }
public boolean add(Equipment equipment) {
this.equipment.add(equipment);
return true;
}
public double netPrice()
{
double netPrice=0.;
Iterator iter=equipment.iterator();
for(iter.hasNext())
netPrice+=((Equipment)iter.next()).netPrice();
return netPrice;
}
public double discountPrice()
{
double discountPrice=0.;
Iterator iter=equipment.iterator();
for(iter.hasNext())
discountPrice+=((Equipment)iter.next()).discountPrice();
return discountPrice;
}
//注意这里,这里就提供用于访问自己组合体内的部件方法。
//上面dIsk 之所以没有,是因为Disk是个单独(Primitive)的元素.
public Iterator iter()
{
return equipment.iterator() ;
{
//重载Iterator方法
public boolean hasNext() { return i//重载Iterator方法
public Object next()
{
if(hasNext())
return equipment.elementAt(i++);
else
throw new NoSuchElementException();
}
}
public class Chassis extends CompositeEquipment
{
public Chassis(String name) { super(name); }
public double netPrice() { return 1.+super.netPrice(); }
public double discountPrice() { return .5+super.discountPrice(); }
}
public class Cabinet extends CompositeEquipment
{
public Cabinet(String name) { super(name); }
public double netPrice() { return 1.+super.netPrice(); }
public double discountPrice() { return .5+super.discountPrice(); }
}
public interface ForumThread {
....
public void addMessage(ForumMessage parentMessage, ForumMessage newMessage)
throws UnauthorizedException;
public void deleteMessage(ForumMessage message)
throws UnauthorizedException;
public Iterator messages();
....
}