一起来学设计模式之模板方法模式

// 抽象类 AbstractClass
abstract class AbstractClass {
    // 模版方法 templateMethod，定义算法骨架
    public final void templateMethod() {
        step1();
        step2();
        step3();
    }
     // 步骤1，抽象方法，由子类实现
    abstract void step1();
     // 步骤2，抽象方法，由子类实现
    abstract void step2();
     // 步骤3，抽象方法，由子类实现
    abstract void step3();
}
 // 具体子类 ConcreteClass1
class ConcreteClass1 extends AbstractClass {
    // 实现步骤1
    void step1() {
        System.out.println("ConcreteClass1: step1");
    }
     // 实现步骤2
    void step2() {
        System.out.println("ConcreteClass1: step2");
    }
     // 实现步骤3
    void step3() {
        System.out.println("ConcreteClass1: step3");
    }
}
 // 具体子类 ConcreteClass2
class ConcreteClass2 extends AbstractClass {
    // 实现步骤1
    void step1() {
        System.out.println("ConcreteClass2: step1");
    }
     // 实现步骤2
    void step2() {
        System.out.println("ConcreteClass2: step2");
    }
     // 实现步骤3
    void step3() {
        System.out.println("ConcreteClass2: step3");
    }
}
 // 客户端代码 Client
public class Client {
    public static void main(String[] args) {
        AbstractClass object1 = new ConcreteClass1();
        object1.templateMethod();
         AbstractClass object2 = new ConcreteClass2();
        object2.templateMethod();
    }
}

ConcreteClass1: step1
ConcreteClass1: step2
ConcreteClass1: step3
ConcreteClass2: step1
ConcreteClass2: step2
ConcreteClass2: step3

// 抽象类 Order
public abstract class Order {
    // 模版方法，定义订单处理流程
    public final void processOrder() {
        createOrder();
        payOrder();
        deliveryOrder();
    }
     // 创建订单，由具体子类实现
    abstract void createOrder();
     // 支付订单，由具体子类实现
    abstract void payOrder();
     // 发货，由具体子类实现
    abstract void deliveryOrder();
}
 // 具体子类 OnlineOrder
public class OnlineOrder extends Order {
    // 实现创建订单
    void createOrder() {
        System.out.println("Online order created");
    }
     // 实现支付订单
    void payOrder() {
        System.out.println("Online order paid and confirmed");
    }
     // 实现发货
    void deliveryOrder() {
        System.out.println("Online order delivered through courier");
    }
}
 // 具体子类 OfflineOrder
public class OfflineOrder extends Order {
    // 实现创建订单
    void createOrder() {
        System.out.println("Offline order created");
    }
     // 实现支付订单
    void payOrder() {
        System.out.println("Offline order paid");
    }
     // 实现发货
    void deliveryOrder() {
        System.out.println("Offline order delivered through physical store");
    }
}
 // 客户端代码 Client
public class Client {
    public static void main(String[] args) {
        Order onlineOrder = new OnlineOrder();
        onlineOrder.processOrder();
         Order offlineOrder = new OfflineOrder();
        offlineOrder.processOrder();
        // Online order created
        // Online order paid and confirmed
        // Online order delivered through courier
        // Offline order created
        // Offline order paid
        // Offline order delivered through physical store
    }
}