Design Pattern(1)-Template Method Pattern

编程时为了提高复用性、可维护性，我们希望把共性的东西提取到一处，这是很自然的想法。但是往往有的时候不是那么容易提取共性， 因为他只是类似，并非一致，又夹杂着差异。典型的例子是JDBC代码。

那么为了实现这种情况下的复用，唯有使粒度变小，将基本的原子操作提为共性。 类图如下：

People类

public abstract class People { abstract void cookWater(); abstract void cleanVegetable(); abstract void washDishes(); void cook(){ cleanVegetable(); cookWater(); washDishes(); } }

ConcretePeople_A类

public class ConcretePeople_A extends People { @Override void cookWater() { System.out.println("A: water has been cooked"); } @Override void cleanVegetable() { System.out.println("A: vegetable has been cleaned"); } @Override void washDishes() { System.out.println("A: dishes have been washed"); } }

ConcretePeople_B类

public class ConcretePeople_B extends People { @Override void cookWater() { System.out.println("B: water has been cooked"); } @Override void cleanVegetable() { System.out.println("B: vegetable has been cleaned"); } @Override void washDishes() { System.out.println("B: dishes have been washed"); } }

main方法：

public class Main { public static void main(String[] args){ People a=new ConcretePeople_A(); People b=new ConcretePeople_B(); a.cook(); b.cook(); } }