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外观模式

蛋糕外观模式 Code

类

/*******************************************************************************
 * Package: com.example.demo.design.facade
 * Type:    AbsCake
 * Date:    2022-04-09 15:29
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.design.facade;

/**
 * 功能描述：
 *
 * @author Songxianyang
 * @date 2022-04-09 15:29
 */
public abstract class AbsCake {
    /**
     * 开启
     */
    public abstract void start();
    
    /**
     * 关闭
     */
    public abstract void end();
    
}

/*******************************************************************************
 * Package: com.example.demo.design.facade
 * Type:    Baking
 * Date:    2022-04-09 15:10
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.design.facade;

/**
 * 功能描述：烘烤
 *
 * @author Songxianyang
 * @date 2022-04-09 15:10
 */
public class Baking extends AbsCake{
    
    @Override
    public void start() {
        System.out.println("开启烘烤机器准备蛋糕");
    }
    
    @Override
    public void end() {
        System.out.println("关闭烘烤机");
    }
}

/*******************************************************************************
 * Package: com.example.demo.design.facade
 * Type:    CakeShopFacade
 * Date:    2022-04-09 15:05
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.design.facade;

/**
 * 功能描述： 蛋糕外观类
 * 我得理解：将功能复杂的调用关系封装在一个方法中，调用端调用即可。比较好理解
 * 例子：蛋糕店： 水果机器、烘烤机、打蛋器、奶油机、、、、
 *
 * @author Songxianyang
 * @date 2022-04-09 15:05
 */

public class CakeShopFacade {
    
    /**
     * 使用聚合的关系来使用对象 对 类的使用不够灵活 用着玩 学习外观模式
     * 面向接口编程 整着玩
     */
    private Baking baking;
    
    private Cream cream;
    
    private Fruits fruits;
    
    private Whisk whisk;
    
    public CakeShopFacade(Baking baking, Cream cream, Fruits fruits, Whisk whisk) {
        this.baking = baking;
        this.cream = cream;
        this.fruits = fruits;
        this.whisk = whisk;
    }
    
    public void startIn() {
        baking.start();
        cream.start();
        fruits.start();
        whisk.start();
    }
    
    public void end() {
        baking.end();
        cream.end();
        fruits.end();
        whisk.end();
    }
}

/*******************************************************************************
 * Package: com.example.demo.design.facade
 * Type:    Cream
 * Date:    2022-04-09 15:28
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.design.facade;

/**
 * 功能描述：奶油机器
 *
 * @author Songxianyang
 * @date 2022-04-09 15:28
 */
public class Cream extends AbsCake{
    
    @Override
    public void start() {
        System.out.println("奶油机器开始打奶油");
    }
    
    @Override
    public void end() {
        System.out.println("奶油机器关闭");
    }
    //、、、、
}

/*******************************************************************************
 * Package: com.example.demo.design.facade
 * Type:    Fruits
 * Date:    2022-04-09 15:09
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.design.facade;

/**
 * 功能描述： 水果机器
 *
 * @author Songxianyang
 * @date 2022-04-09 15:09
 */
public class Fruits extends AbsCake{
    @Override
    public void start() {
        System.out.println("各种水果已经做好");
    }
    
    @Override
    public void end() {
        System.out.println("关闭水果机器");
    }
    
}

/*******************************************************************************
 * Package: com.example.demo.design.facade
 * Type:    Test
 * Date:    2022-04-09 15:44
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.design.facade;

/**
 * 功能描述：
 *
 * @author Songxianyang
 * @date 2022-04-09 15:44
 */
public class Test {
    public static void main(String[] args) {
        CakeShopFacade facade = new CakeShopFacade(new Baking(), new Cream(), new Fruits(), new Whisk());
        facade.startIn();
    }
}

/*******************************************************************************
 * Package: com.example.demo.design.facade
 * Type:    Whisk
 * Date:    2022-04-09 15:10
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.design.facade;

/**
 * 功能描述：打蛋器
 *
 * @author Songxianyang
 * @date 2022-04-09 15:10
 */
public class Whisk extends AbsCake{
    @Override
    public void start() {
        System.out.println("打蛋器开始打蛋");
    }
    
    @Override
    public void end() {
        System.out.println("关闭打蛋器");
    }
}

测试结果

mybaitis 底层 外感模式 源码分析

/*******************************************************************************
 * Package: com.example.demo.jdk
 * Type:    MybatisFacade
 * Date:    2022-04-09 15:45
 *
 * Copyright (c) 2022 HUANENG GUICHENG TRUST CORP.,LTD All Rights Reserved.
 *
 * You may not use this file except in compliance with the License.
 *******************************************************************************/
package com.example.demo.jdk;

import org.apache.ibatis.session.Configuration;

/**
 * 功能描述：外观模式下的mybatis
 *
 * @author Songxianyang
 * @date 2022-04-09 15:45
 */
public class MybatisFacade {
    public static void main(String[] args) {
        new Configuration();
    }
}
分析如下
public MetaObject newMetaObject(Object object) {
        return MetaObject.forObject(object, this.objectFactory, this.objectWrapperFactory, this.reflectorFactory);
    }
其中调用的方法：
public static MetaObject forObject(Object object, ObjectFactory objectFactory, ObjectWrapperFactory objectWrapperFactory, ReflectorFactory reflectorFactory) {
        return object == null ? SystemMetaObject.NULL_META_OBJECT : new MetaObject(object, objectFactory, objectWrapperFactory, reflectorFactory);
    }
在掉构造器
    private MetaObject(Object object, ObjectFactory objectFactory, ObjectWrapperFactory objectWrapperFactory, ReflectorFactory reflectorFactory) {
        this.originalObject = object;
        this.objectFactory = objectFactory;
        this.objectWrapperFactory = objectWrapperFactory;
        this.reflectorFactory = reflectorFactory;
        if (object instanceof ObjectWrapper) {
            this.objectWrapper = (ObjectWrapper)object;
        } else if (objectWrapperFactory.hasWrapperFor(object)) {
            this.objectWrapper = objectWrapperFactory.getWrapperFor(this, object);
        } else if (object instanceof Map) {
            this.objectWrapper = new MapWrapper(this, (Map)object);
        } else if (object instanceof Collection) {
            this.objectWrapper = new CollectionWrapper(this, (Collection)object);
        } else {
            this.objectWrapper = new BeanWrapper(this, object);
        }

    }