设计模式-模板方法实现
// 抽象类：饮品制作流程
abstract class Beverage {
// 模板方法：定义饮品制作的算法骨架
public final void prepareRecipe() {
boilWater();
brew();
pourInCup();
if (customerWantsCondiments()) {
addCondiments();
}
}
// 公共步骤，所有饮品都需要
private void boilWater() {
System.out.println("Boiling water.");
}
private void pourInCup() {
System.out.println("Pouring into cup.");
}
// 抽象步骤，由子类实现
protected abstract void brew();
protected abstract void addCondiments();
// 钩子方法：提供默认实现，子类可选择覆盖
protected boolean customerWantsCondiments() {
return true;
}
}
// 具体类：制作茶
class Tea extends Beverage {
@Override
protected void brew() {
System.out.println("Steeping the tea.");
}
@Override
protected void addCondiments() {
System.out.println("Adding lemon.");
}
}
// 具体类：制作咖啡
class Coffee extends Beverage {
@Override
protected void brew() {
System.out.println("Dripping coffee through filter.");
}
@Override
protected void addCondiments() {
System.out.println("Adding sugar and milk.");
}
}
// 测试代码
public class TemplateMethodExample {
public static void main(String[] args) {
System.out.println("Making tea:");
Beverage tea = new Tea();
tea.prepareRecipe();
System.out.println("\nMaking coffee:");
Beverage coffee = new Coffee();
coffee.prepareRecipe();
}
}