天天看点

【设计模式】【第四章】【订单状态流转】【状态模式 + 享元模式+模板方法模式】

文章目录

  • ​​创建design-demo项目​​
  • ​​创建OrderController​​
  • ​​创建OrderService​​
  • ​​创建OrderServiceImpl​​
  • ​​创建AbstractAuditLogProcessor​​
  • ​​创建AuditLog​​
  • ​​创建LoginLogProcessor​​
  • ​​创建OrderLogProcessor​​
  • ​​创建PayLogProcessor​​
  • ​​创建Order​​
  • ​​创建OrderState​​
  • ​​创建OrderStateChangeAction​​
  • ​​创建OrderStateMachineConfig​​
  • ​​创建OrderStateListener​​
  • ​​创建StrategyFacade​​
  • ​​创建AddFuncFactory​​
  • ​​创建PayFactory​​
  • ​​创建StrategyFactory​​
  • ​​创建AddFuncDecorator​​
  • ​​创建AbstractAddFuncDecorator​​
  • ​​创建StrategyEnum​​
  • ​​校验是否正常工作​​

创建design-demo项目

项目代码:​​https://gitee.com/java_wxid/java_wxid/tree/master/demo/design-demo​​ 项目结构如下(示例):

【设计模式】【第四章】【订单状态流转】【状态模式 + 享元模式+模板方法模式】

创建OrderController

代码如下(示例):

package com.example.designdemo.controller;

import com.example.designdemo.order.pojo.Order;
import com.example.designdemo.pay.pojo.PayBody;
import com.example.designdemo.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description: 订单管理,这里简单写写,主要是设计模式,别抠细节
 */
@RestController
public class OrderController {
    @Autowired
    private OrderService orderService;

    @GetMapping("mkOrder")
    public Order createOrder(@RequestParam Integer oid) {
        return orderService.createOrder(oid);
    }

    @PostMapping("/pay")
    public Order payOrder(@RequestBody PayBody payBody){
        return orderService.pay(payBody);
    }

    @GetMapping("/send")
    public Order send(@RequestParam Integer oid) {
        return orderService.send(oid);
    }

    @GetMapping("/receive")
    public Order receive(@RequestParam Integer oid) {
        return orderService.receive(oid);
    }
}
      

创建OrderService

代码如下(示例):

package com.example.designdemo.service;

import com.example.designdemo.order.pojo.Order;
import com.example.designdemo.pay.pojo.PayBody;

/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/25 9:28
 * @Description:
 */
public interface OrderService {

    Order createOrder(Integer oid);

    Order pay(PayBody payBody);

    Order send(Integer oid);

    Order receive(Integer oid);
}
      

创建OrderServiceImpl

代码如下(示例):

package com.example.designdemo.service.impl;
import com.example.designdemo.order.auditlog.OrderLogProcessor;
 import com.example.designdemo.order.auditlog.PayLogProcessor;
 import com.example.designdemo.order.pojo.Order;
 import com.example.designdemo.order.pojo.OrderState;
 import com.example.designdemo.order.pojo.OrderStateChangeAction;
 import com.example.designdemo.pay.facade.StrategyFacade;
 import com.example.designdemo.pay.pojo.PayBody;
 import com.example.designdemo.service.OrderService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.support.MessageBuilder;
 import org.springframework.statemachine.StateMachine;
 import org.springframework.statemachine.persist.StateMachinePersister;
 import org.springframework.stereotype.Service;
 import java.util.ArrayList;
 import java.util.List;
 /**• @Author: zhiwei Liao
• @Date: 2022/9/26 21:29
• @Description:
 */
 @Service
 public class OrderServiceImpl implements OrderService {
@Autowired
 private StateMachine<OrderState, OrderStateChangeAction> orderStateMachine;
@Autowired
 private StateMachinePersister<OrderState, OrderStateChangeAction, Order> stateMachinePersister;
@Autowired
 private PayLogProcessor payLogProcessor;
@Autowired
 private OrderLogProcessor orderLogProcessor;
//模拟一个存储
 private List orders = new ArrayList<>();
public Order createOrder(Integer oid) {
 Order order = new Order();
 order.setOrderState(OrderState.ORDER_WAIT_PAY);
 order.setOrderId(oid);
 // 创建的order是不是得入库啊?如果不入库,下次访问的时候,是不是找不到了啊。
 orders.add(order); // 模拟存储到 db
 orderLogProcessor.processAuditLog(“acccount”, “createOrder”, oid.toString());
 return order;
 }
// 将来我们删除或者增加或者修改任何关于付款的模块,无需改动service。
 //不会对调用层产生任何代码的改动。
 // 调用层使用我们的pay 模块,无需关系实现的逻辑,只需要将入参传给我们的pay模块即可。
 public Order pay(PayBody payBody) {
 // 书写我们的付款逻辑
 boolean flag = false;
 flag = StrategyFacade.pay(payBody);
 if(flag) {
 Order order = (Order) orders.get(0); // 模拟查询db代码
 payLogProcessor.processAuditLog(payBody.getAccount(), “pay”, order.getOrderId().toString());
 Message message = MessageBuilder
 .withPayload(OrderStateChangeAction.PAY_ORDER).setHeader(“order”, order).build();
 //发送消息,发送给谁?和状态机有没有关系啊? 有
 if(changeStateAction(message,order)) {
 return order;
 }
 //如果是 true,我们要保存到db
 saveToDb(payBody);
 }
 return null;
 }
 private void saveToDb(PayBody payBody) {
 }
public Order send(Integer oid) {
 Order order = (Order) orders.get(0); // 模拟查询db代码
 Message message = MessageBuilder
 .withPayload(OrderStateChangeAction.SEND_ORDER).setHeader(“order”, order).build();
 if(changeStateAction(message,order)) {
 return order;
 }
 return null;
 }
public Order receive(Integer oid) {
 Order order = (Order) orders.get(0); // 模拟查询db代码
 Message message = MessageBuilder
 .withPayload(OrderStateChangeAction.RECEIVE_ORDER).setHeader(“order”, order).build();
 if(changeStateAction(message,order)) {
 return order;
 }
 return null;
 }
private boolean changeStateAction(Message message, Order order) {
 try {
 orderStateMachine.start();
 stateMachinePersister.restore(orderStateMachine, order); // 待议
 boolean res = orderStateMachine.sendEvent(message);
 stateMachinePersister.persist(orderStateMachine, order); // 持久
 return res;
 } catch (Exception e) {
 e.printStackTrace();
 } finally {
 orderStateMachine.stop();
 }
 return false;
 }
 }      

创建AbstractAuditLogProcessor

代码如下(示例):

package com.example.designdemo.order.auditlog;

import com.example.designdemo.order.auditlog.pojo.AuditLog;

import java.util.Date;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:
 */
public abstract class AbstractAuditLogProcessor {
    // 创建我们的 AuditLog (基础部分)
    public final AuditLog buildAuditLog(String account, String action, String orderId){
        AuditLog auditLog = new AuditLog();
        auditLog.setAccount(account);
        auditLog.setAction(action);
        auditLog.setOrderId(orderId);
        auditLog.setDate(new Date());
        return auditLog;
    }

    protected abstract AuditLog buildDetails(AuditLog auditLog);

    public final void sendToQueue(AuditLog auditLog) {
        //send toQueue(auditLog)
    }

    public final void processAuditLog(String account, String action, String orderId) {
        this.sendToQueue(buildDetails(buildAuditLog(account, action, orderId)));
    }
}
      

创建AuditLog

代码如下(示例):

package com.example.designdemo.order.auditlog.pojo;
import java.util.Date;
 /**• @Author: zhiwei Liao
• @Date: 2022/9/26 21:29
• @Description:
 */
 public class AuditLog {
 private String account;
 private String action;
 private Date date;
 private String orderId;
 private Object details; //订单创建需要有相关产品信息;
 // 订单支付需要有相关产品信息以及支付方式和支付金额。
public String getAccount() {
 return account;
 }
public void setAccount(String account) {
 this.account = account;
 }
public String getAction() {
 return action;
 }
public void setAction(String action) {
 this.action = action;
 }
public Date getDate() {
 return date;
 }
public void setDate(Date date) {
 this.date = date;
 }
public String getOrderId() {
 return orderId;
 }
public void setOrderId(String orderId) {
 this.orderId = orderId;
 }
public Object getDetails() {
 return details;
 }
public void setDetails(Object details) {
 this.details = details;
 }
@Override
 public String toString() {
 return “AuditLog{” +
 “account='” + account + ‘’’ +
 “, action='” + action + ‘’’ +
 “, date=” + date +
 “, orderId='” + orderId + ‘’’ +
 “, details=” + details +
 ‘}’;
 }
 }      

创建LoginLogProcessor

代码如下(示例):

package com.example.designdemo.order.auditlog;

import com.example.designdemo.order.auditlog.pojo.AuditLog;
import org.springframework.stereotype.Component;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:
 */
@Component
public class LoginLogProcessor extends AbstractAuditLogProcessor{
    @Override
    protected AuditLog buildDetails(AuditLog auditLog) {
        return auditLog;
    }
}
      

创建OrderLogProcessor

代码如下(示例):

package com.example.designdemo.order.auditlog;

import com.example.designdemo.order.auditlog.pojo.AuditLog;
import org.springframework.stereotype.Component;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:
 */
@Component
public class OrderLogProcessor extends AbstractAuditLogProcessor{
    @Override
    protected AuditLog buildDetails(AuditLog auditLog) {
        String orderId = auditLog.getOrderId();
        String productDetails = "通过 orderId 获取";
        auditLog.setDetails(productDetails);
        System.out.println(auditLog);
        return auditLog;
    }
}
      

创建PayLogProcessor

代码如下(示例):

package com.example.designdemo.order.auditlog;

import com.example.designdemo.order.auditlog.pojo.AuditLog;
import org.springframework.stereotype.Component;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:
 */
@Component
public class PayLogProcessor extends AbstractAuditLogProcessor{
    @Override
    protected AuditLog buildDetails(AuditLog auditLog) {
        String orderId = auditLog.getOrderId();
        String allDetails = "通过 orderId 或者是参数 获取产品信息,金额,支付方式";
        auditLog.setDetails(allDetails);
        System.out.println(auditLog);
        return auditLog;
    }
}
      

创建Order

代码如下(示例):

package com.example.designdemo.order.pojo;

/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:状态转化的一个控制机。状态机:初始化状态;配置我们的所有状态之间的转化关系;一些持久化的工作(redis)。
 */
public class Order {
    private Integer orderId;
    private OrderState orderState;//订单状态

    public Integer getOrderId() {
        return orderId;
    }

    public void setOrderId(Integer orderId) {
        this.orderId = orderId;
    }

    public OrderState getOrderState() {
        return orderState;
    }

    public void setOrderState(OrderState orderState) {
        this.orderState = orderState;
    }
}
      

创建OrderState

代码如下(示例):

package com.example.designdemo.order.pojo;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:订单状态
 */
public enum  OrderState {
    ORDER_WAIT_PAY, // 待支付
    ORDER_WAIT_SEND, // 待发货
    ORDER_WAIT_RECEIVE, // 待收货
    ORDER_FINISH; // 完成订单
}
      

创建OrderStateChangeAction

代码如下(示例):

package com.example.designdemo.order.pojo;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:订单状态操作
 */
public enum OrderStateChangeAction {
    PAY_ORDER, // 支付操作
    SEND_ORDER, // 发货操作
    RECEIVE_ORDER; // 收货操作
}
      

创建OrderStateMachineConfig

代码如下(示例):

package com.example.designdemo.order.config;

import com.example.designdemo.order.pojo.Order;
import com.example.designdemo.order.pojo.OrderState;
import com.example.designdemo.order.pojo.OrderStateChangeAction;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.statemachine.StateMachineContext;
import org.springframework.statemachine.StateMachinePersist;
import org.springframework.statemachine.config.EnableStateMachine;
import org.springframework.statemachine.config.StateMachineConfigurerAdapter;
import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;
import org.springframework.statemachine.persist.DefaultStateMachinePersister;
import org.springframework.statemachine.support.DefaultStateMachineContext;
import java.util.EnumSet;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:
 */
@Configuration
@EnableStateMachine(name="orderStateMachine")
public class OrderStateMachineConfig extends StateMachineConfigurerAdapter<OrderState, OrderStateChangeAction> {
    public void configure(StateMachineStateConfigurer<OrderState, OrderStateChangeAction> states) throws Exception {
        states.withStates().initial(OrderState.ORDER_WAIT_PAY)
                .states(EnumSet.allOf(OrderState.class));
    }

    public void configure(StateMachineTransitionConfigurer<OrderState, 
                                    OrderStateChangeAction> transitions) throws Exception {
        transitions.withExternal().source(OrderState.ORDER_WAIT_PAY)
                .target(OrderState.ORDER_WAIT_SEND)
                .event(OrderStateChangeAction.PAY_ORDER)
                .and()
                .withExternal().source(OrderState.ORDER_WAIT_SEND)
                .target(OrderState.ORDER_WAIT_RECEIVE)
                .event(OrderStateChangeAction.SEND_ORDER)
                .and()
                .withExternal().source(OrderState.ORDER_WAIT_RECEIVE)
                .target(OrderState.ORDER_FINISH)
                .event(OrderStateChangeAction.RECEIVE_ORDER);
    }

    // 配置状态机持久化
    @Bean
    public DefaultStateMachinePersister machinePersister() {
        return new DefaultStateMachinePersister<>(new StateMachinePersist<Object, Object, Order>() {

            @Override
            public void write(StateMachineContext<Object, Object> stateMachineContext, Order order) throws Exception {
                //持久化操作。可以通过任何形式进行持久化。redis 、 mongodb、mysql,ecache
            }

            @Override
            public StateMachineContext<Object, Object> read(Order order) throws Exception {
                // 本来是应该从持久化组件里进行读取的。但是没做持久化
                return new DefaultStateMachineContext(order.getOrderState(), null, null, null);
            }
        });
    }
}
      

创建OrderStateListener

代码如下(示例):

package com.example.designdemo.order.listener;

import com.example.designdemo.order.pojo.Order;
import com.example.designdemo.order.pojo.OrderState;
import com.example.designdemo.order.pojo.OrderStateChangeAction;
import org.springframework.messaging.Message;
import org.springframework.statemachine.annotation.OnTransition;
import org.springframework.statemachine.annotation.WithStateMachine;
import org.springframework.stereotype.Component;

/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/26 21:29
 * @Description:监听器是监听到 action 后进行状态的一个变更。
 */
@Component("orderStateListener")
@WithStateMachine(name="orderStateMachine")
public class OrderStateListener {
    @OnTransition(source = "ORDER_WAIT_PAY", target = "ORDER_WAIT_SEND")
    public boolean payToSend(Message<OrderStateChangeAction> message){
        Order order = (Order) message.getHeaders().get("order");
        order.setOrderState(OrderState.ORDER_WAIT_SEND);
        return true;
    }
    @OnTransition(source = "ORDER_WAIT_SEND", target = "ORDER_WAIT_RECEIVE")
    public boolean sendToReceive(Message<OrderStateChangeAction> message){
        Order order = (Order) message.getHeaders().get("order");
        order.setOrderState(OrderState.ORDER_WAIT_RECEIVE);
        return true;
    }
    @OnTransition(source = "ORDER_WAIT_RECEIVE", target = "ORDER_FINISH")
    public boolean receiveToFinish(Message<OrderStateChangeAction> message){
        Order order = (Order) message.getHeaders().get("order");
        order.setOrderState(OrderState.ORDER_FINISH);
        return true;
    }

}
      

创建StrategyFacade

代码如下(示例):

package com.example.designdemo.pay.facade;

import com.example.designdemo.pay.additionalDecorator.AddFuncDecorator;
import com.example.designdemo.pay.context.PayContext;
import com.example.designdemo.pay.factory.AddFuncFactory;
import com.example.designdemo.pay.factory.PayFactory;
import com.example.designdemo.pay.strategy.PayStrategy;
import com.example.designdemo.pay.factory.StrategyFactory;
import com.example.designdemo.pay.pojo.PayBody;
import com.example.designdemo.pay.strategyEnum.StrategyEnum;

/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/25 11:27
 * @Description: 门面模式,最终只暴露门面即可,门面就是我们的超级封装
 */

public class StrategyFacade {

    // 定义一个map,将对应关系提前初始化好。
    // 双十一的时候,有大量的用户进行下单(千万级),就会造成千万级的pay接口的调用。
    // 很可惜,这部分代码里边有两个 new 关键字(new PayContext(payStrategy) 和 new AddFuncDecorator)。
    // 如果瞬时见。有几十万的并发进来,那么会创建几十万个 context对象和 addFunc对象,造成 年轻代的eden区的频繁对象创建
    // 虽然说调用完就进行了对象的垃圾收集,但是这么多的访问对象进来会造成,minorgc。
    // 1. 单例模式吗?PayContext创建是基于payStrategy,不止一种paycontext啊,用单例不行呀。 AddFuncDecorator 是基于PayContext
    // 创建的,PayContext 不止一种,AddFuncDecorator 也不止一种。
    // 2. 享元模式。享元模式是单例模式的一种思想升级。单例模式,针对的是同一种对象,没有任何不同的细节。而享元模式,针对多个对象。
    // 多个对象:同一种class,但是里边的属性有些许不同。PayContext是同一种对象吧?是的; PayContext 是不是有细节上的不同呢?是的,
    // payStrategy不同; 那么我们是否可以知道这个PayContext的种类数量呢?是的,目前有三种。 享元模式能够对这可控数量的有不同细节的
    //同一种class对象进行共享,保证我们的程序不频繁的创建对象。
    public static Boolean pay(PayBody payBody) {
        //获取我们的 策略枚举
        StrategyEnum strategyEnum = getStrategyEnum(payBody.getType());
        if(strategyEnum == null) {
            return false;
        }
        //获取我们的策略对象
        PayStrategy payStrategy = StrategyFactory.getPayStrategy(strategyEnum);
        //生成我们的策略上下文
        PayContext context = PayFactory.getPayContext(payStrategy); // 享元模式解决高并发下频繁创建对象的问题
        // 装饰一下 context,。立马多了一个功能
        // 我看这行代码啊,就不顺眼。代理模式搞他。
        AddFuncDecorator addFuncDecorator = (AddFuncDecorator) AddFuncFactory.getAddFunc(context); // 享元模式解决高并发下频繁创建对象的问题
        //进行扣款
        return addFuncDecorator.execute(payBody);
    }

    private static StrategyEnum getStrategyEnum(int type) {
        switch (type) {
            case 0:
                return StrategyEnum.ZfbPayStrategy;
            case 1:
                return StrategyEnum.WxPayStrategy;
            case 2:
                return StrategyEnum.BankPayStrategy;
            default:
                return null;
        }
    }

}
      

创建AddFuncFactory

代码如下(示例):

package com.example.designdemo.pay.factory;

import com.example.designdemo.pay.additionalDecorator.AbstractAddFuncDecorator;
import com.example.designdemo.pay.additionalDecorator.AddFuncDecorator;
import com.example.designdemo.pay.context.PayContext;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/25 20:53
 * @Description:
 */
public class AddFuncFactory {
    // 工厂的目的是生产 AddFuncDecorator; 生产几个啊? 多个:享元
    // key 应该是能够和 AbstractAddFuncDecorator 做成对应的东西。
    // 这个map最多保存是三个对象。
    public final static Map<PayContext, AbstractAddFuncDecorator> maps = new ConcurrentHashMap<>();

    public static AbstractAddFuncDecorator getAddFunc(PayContext payContext) {
        if(maps.get(payContext) == null) {
            AddFuncDecorator addFuncDecorator = new AddFuncDecorator(payContext);
            maps.put(payContext, addFuncDecorator);
        }
        return maps.get(payContext);
    }
}
      

创建PayFactory

代码如下(示例):

package com.example.designdemo.pay.factory;


import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import com.example.designdemo.pay.context.PayContext;
import com.example.designdemo.pay.strategy.PayStrategy;

/**
 * @author zhiweiLiao<zhiwei.liao @ sgs.com>
 * @Description 享元模式解决高并发下频繁创建对象的问题
 * @Date create in 2022/9/28 0028 13:57
 */
public class PayFactory {

    public final static Map<PayStrategy, PayContext> maps = new ConcurrentHashMap<>();

    public static PayContext getPayContext(PayStrategy payStrategy) {
        if(maps.get(payStrategy) == null) {
            PayContext payContext = new PayContext(payStrategy);
            maps.put(payStrategy, payContext);
        }
        return maps.get(payStrategy);
    }

}
      

创建StrategyFactory

代码如下(示例):

package com.example.designdemo.pay.factory;

import com.example.designdemo.pay.strategy.PayStrategy;
import com.example.designdemo.pay.strategyEnum.StrategyEnum;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/25 10:53
 * @Description: 策略工厂 工厂类依靠策略枚举返回策略类 后面都不需要修改了,因为它是一个无状态的 使用饿汉单例模式创建
 */

public class StrategyFactory {

    private static final Map<String, PayStrategy> strategyMaps = new ConcurrentHashMap();

    public static PayStrategy getPayStrategy(StrategyEnum strategyEnum){
        PayStrategy payStrategy = strategyMaps.get(strategyEnum.getValue());
        try {
            payStrategy = (PayStrategy) Class.forName(strategyEnum.getValue()).newInstance();
            strategyMaps.put(strategyEnum.getValue(), payStrategy);
        } catch (Exception e) {
            //异常信息打印
        }
        return payStrategy;
    }

}
      

创建AddFuncDecorator

代码如下(示例):

package com.example.designdemo.pay.additionalDecorator;

import com.example.designdemo.pay.context.AbstractPayContext;
import com.example.designdemo.pay.pojo.PayBody;

/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/25 20:53
 * @Description:abstractPayContext 不是共享的,因为有的小伙伴选择 zfb 支付,有的小伙伴选择wx支付,等等。。。
 */
public class AddFuncDecorator extends AbstractAddFuncDecorator{
    public AddFuncDecorator(AbstractPayContext abstractPayContext) {
        super(abstractPayContext);
    }

    // 新活儿
    @Override
    public void additionalFunction(PayBody payBody) { // 共享的,跟支付策略没有任何关系
        String product = payBody.getProduct();
        // 从db里边获取 product的详细信息。
        // 从配置中心(redis缓存)里获取产品的更新策略。
        // 根据策略更新用户平台币 或(和) 发放红包。
        System.out.println("更新平台币成功,发送红包到用户优惠券模块成功。");
    }

    @Override
    public Boolean execute(PayBody payBody) { // 算共享的。共享的调用逻辑
        Boolean result = super.execute(payBody); //老活儿
        this.additionalFunction(payBody); // 新活儿. 新活儿的各种重试,失败补偿
        return result;
    }

}
      

创建AbstractAddFuncDecorator

代码如下(示例):

package com.example.designdemo.pay.additionalDecorator;


import com.example.designdemo.pay.context.AbstractPayContext;
import com.example.designdemo.pay.pojo.PayBody;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/25 20:53
 * @Description:
 */
public abstract class AbstractAddFuncDecorator extends AbstractPayContext {
    // 这是我们的装饰器类。专门干装修的。 专门添加新功能的(平台币,红包)
    // 装饰的是谁啊? 我作为一个称职的装饰器,我必须得知道装饰的是谁,不然我咋干活儿啊。
    private AbstractPayContext abstractPayContext = null;

    public AbstractAddFuncDecorator(AbstractPayContext abstractPayContext) {
        this.abstractPayContext = abstractPayContext;
    }

    // 开始干活儿
    //1. 老活儿。 支付。但是我又不能修改支付代码,也不能修改支付逻辑。
    @Override
    public Boolean execute(PayBody payBody) {
        return abstractPayContext.execute(payBody);
    }

    //2. 老活儿不合适,没你装饰器照样能execute。 新活儿:平台币,红包)
    public abstract void additionalFunction(PayBody payBody);
}      

创建StrategyEnum

代码如下(示例):

package com.example.designdemo.pay.strategyEnum;
/**
 * @Author: zhiwei Liao
 * @Date: 2022/9/25 10:56
 * @Description: 准备使用反射
 */

public enum StrategyEnum {

    ZfbPayStrategy("com.example.designdemo.pay.strategy.ZfbPayStrategy"),
    WxPayStrategy("com.example.designdemo.pay.strategy.WxPayStrategy"),
    BankPayStrategy("com.example.designdemo.pay.strategy.BankPayStrategy");

    String value = "";

    StrategyEnum(String value){
        this.value = value;
    }

    public String getValue(){
        return this.value;
    }
}
      

校验是否正常工作

【设计模式】【第四章】【订单状态流转】【状态模式 + 享元模式+模板方法模式】
【设计模式】【第四章】【订单状态流转】【状态模式 + 享元模式+模板方法模式】
【设计模式】【第四章】【订单状态流转】【状态模式 + 享元模式+模板方法模式】

继续阅读