Java设计模式（七） 模板模式

【模板模式】在一个方法中定义了一个算法的骨架，而将一些步骤延迟到子类中。模板方法使得子类可以在不改变算法结构的情况下，重新定义算法中的某些步骤。

1，定义模板类

package com.pattern.template;public abstract class CaffeineBeverage {final void prepareRecipe(){
boilWater();
brew();
pourInCup();
addCondiments();
}abstract void brew();
abstract void addCondiments();void boilWater(){
System.out.println("Boiling water");
}void pourInCup(){
System.out.println("Pouring into cup");
}}

2，定义模板的子类实现类

package com.pattern.template;public class Coffee extends CaffeineBeverage{/**
* @see com.pattern.template.CaffeineBeverage#brew()
*/
@Override
void brew() {
System.out.println("Dripping Coffee through filter");
}/**
* @see com.pattern.template.CaffeineBeverage#addCondiments()
*/
@Override
void addCondiments() {
System.out.println("Adding Sugar and Milk");
}
}

package com.pattern.template;public class Tea extends CaffeineBeverage{/**
* @see com.pattern.template.CaffeineBeverage#brew()
*/
@Override
void brew() {
System.out.println("Steeping the tea");
}/**
* @see com.pattern.template.CaffeineBeverage#addCondiments()
*/
@Override
void addCondiments() {
System.out.println("Adding Lemon");
}}

3，测试类

package com.pattern.template;public class BeverageTestDrive {public static void main(String[] args) {
Coffee coffee = new Coffee();
coffee.prepareRecipe();
}
}

运行结果如下：

Boiling water

Dripping Coffee through filter

Pouring into cup

Adding Sugar and Milk

类图如下所示：