add strategy

Author: laileon

src/com/blankj/custom/factory/Benz.java renamed to src/com/blankj/custom/desingn_pattern/factory/Benz.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.factory;
+package com.blankj.custom.desingn_pattern.factory;
 
 public class Benz implements Car {
 

src/com/blankj/custom/factory/BenzFactory.java renamed to src/com/blankj/custom/desingn_pattern/factory/BenzFactory.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.factory;
+package com.blankj.custom.desingn_pattern.factory;
 
 public interface BenzFactory {
 	static Car createCar() {

src/com/blankj/custom/factory/Bmw.java renamed to src/com/blankj/custom/desingn_pattern/factory/Bmw.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.factory;
+package com.blankj.custom.desingn_pattern.factory;
 
 public class Bmw implements Car{
 

src/com/blankj/custom/factory/BmwFactory.java renamed to src/com/blankj/custom/desingn_pattern/factory/BmwFactory.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.factory;
+package com.blankj.custom.desingn_pattern.factory;
 
 public interface BmwFactory {
 	static Car createCar() {

src/com/blankj/custom/desingn_pattern/factory/Car.java

@@ -0,0 +1,5 @@
+package com.blankj.custom.desingn_pattern.factory;
+
+public interface Car {
+	void create();
+}

src/com/blankj/custom/factory/Main.java renamed to src/com/blankj/custom/desingn_pattern/factory/Main.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.factory;
+package com.blankj.custom.desingn_pattern.factory;
 
 public class Main {
 	public static void main(String[] args) {

src/com/blankj/custom/single/Single1.java renamed to src/com/blankj/custom/desingn_pattern/single/Single1.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.single;
+package com.blankj.custom.desingn_pattern.single;
 
 // 懒汉式（线程安全问题）
 public class Single1 {

src/com/blankj/custom/single/Single2.java renamed to src/com/blankj/custom/desingn_pattern/single/Single2.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.single;
+package com.blankj.custom.desingn_pattern.single;
 
 // 懒汉式（）
 public class Single2 {

src/com/blankj/custom/single/Single3.java renamed to src/com/blankj/custom/desingn_pattern/single/Single3.java

@@ -1,4 +1,4 @@
-package com.blankj.custom.single;
+package com.blankj.custom.desingn_pattern.single;
 
 /**
  * 码家学院

src/com/blankj/custom/desingn_pattern/strategy/ConcreteStrategyA.java

@@ -0,0 +1,8 @@
+package com.blankj.custom.desingn_pattern.strategy;
+
+public class ConcreteStrategyA implements Strategy {
+    @Override
+    public void strategyInterface() {
+        //相关的业务
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/ConcreteStrategyB.java

@@ -0,0 +1,8 @@
+package com.blankj.custom.desingn_pattern.strategy;
+
+public class ConcreteStrategyB implements Strategy {
+    @Override
+    public void strategyInterface() {
+        //相关的业务
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/Context.java

@@ -0,0 +1,22 @@
+package com.blankj.custom.desingn_pattern.strategy;
+
+public class Context {
+    //持有一个具体策略的对象
+    private Strategy strategy;
+
+    /**
+     * 构造函数，传入一个具体策略对象
+     *
+     * @param strategy 具体策略对象
+     */
+    public Context(Strategy strategy) {
+        this.strategy = strategy;
+    }
+
+    /**
+     * 策略方法
+     */
+    public void contextInterface() {
+        strategy.strategyInterface();
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/ReadMe

@@ -0,0 +1,7 @@
+这个模式涉及到三个角色：
+
+环境(Context)角色：持有一个Strategy的引用。
+
+抽象策略(Strategy)角色：这是一个抽象角色，通常由一个接口或抽象类实现。此角色给出所有的具体策略类所需的接口。
+
+具体策略(ConcreteStrategy)角色：包装了相关的算法或行为。

src/com/blankj/custom/desingn_pattern/strategy/Strategy.java

@@ -0,0 +1,8 @@
+package com.blankj.custom.desingn_pattern.strategy;
+
+public interface Strategy {
+    /**
+     * 策略方法
+     */
+    void strategyInterface();
+}

src/com/blankj/custom/desingn_pattern/strategy/example/CalPrice.java

@@ -0,0 +1,6 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+public interface CalPrice {
+    //根据原价返回一个最终的价格
+    Double calPrice(Double orgnicPrice);
+}

src/com/blankj/custom/desingn_pattern/strategy/example/CalPriceFactory.java

@@ -0,0 +1,111 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+public class CalPriceFactory {
+    private CalPriceFactory() {
+    }
+
+    //根据客户的总金额产生相应的策略
+    public static CalPrice createCalPrice(Player customer) {
+        if (customer.getTotalAmount() > 30000) {//3000则改为金牌会员计算方式
+            return new GoldVip();
+        } else if (customer.getTotalAmount() > 20000) {//类似
+            return new SuperVip();
+        } else if (customer.getTotalAmount() > 10000) {//类似
+            return new Vip();
+        } else {
+            return new Orgnic();
+        }
+    }
+
+//    private static final String CAL_PRICE_PACKAGE = "com.blankj.custom.desingn_pattern.strategy.example";//这里是一个常量，表示我们扫描策略的包
+//
+//    private ClassLoader classLoader = getClass().getClassLoader();
+//
+//    private List<Class<? extends CalPrice>> calPriceList;//策略列表
+//
+//    //根据玩家的总金额产生相应的策略
+//    public CalPrice createCalPrice(Player player) {
+//        //在策略列表查找策略
+//        for (Class<? extends CalPrice> clazz : calPriceList) {
+//            PriceRegion validRegion = handleAnnotation(clazz);//获取该策略的注解
+//            //判断金额是否在注解的区间
+//            if (player.getTotalAmount() > validRegion.min() && player.getTotalAmount() < validRegion.max()) {
+//                try {
+//                    //是的话我们返回一个当前策略的实例
+//                    return clazz.newInstance();
+//                } catch (Exception e) {
+//                    throw new RuntimeException("策略获得失败");
+//                }
+//            }
+//        }
+//        throw new RuntimeException("策略获得失败");
+//    }
+//
+//    private PriceRegion handleAnnotation(Class<? extends CalPrice> clazz) {
+//        Annotation[] annotations = clazz.getDeclaredAnnotations();
+//        if (annotations == null || annotations.length == 0) {
+//            return null;
+//        }
+//        for (int i = 0; i < annotations.length; i++) {
+//            if (annotations[i] instanceof PriceRegion) {
+//                return (PriceRegion) annotations[i];
+//            }
+//        }
+//        return null;
+//    }
+//
+//    //单例
+//    private CalPriceFactory() {
+//        init();
+//    }
+//
+//    //在工厂初始化时要初始化策略列表
+//    private void init() {
+//        calPriceList = new ArrayList<Class<? extends CalPrice>>();
+//        File[] resources = getResources();//获取到包下所有的class文件
+//        Class<CalPrice> calPriceClazz = null;
+//        try {
+//            calPriceClazz = (Class<CalPrice>) classLoader.loadClass(CalPrice.class.getName());//使用相同的加载器加载策略接口
+//        } catch (ClassNotFoundException e1) {
+//            throw new RuntimeException("未找到策略接口");
+//        }
+//        for (int i = 0; i < resources.length; i++) {
+//            try {
+//                //载入包下的类
+//                Class<?> clazz = classLoader.loadClass(CAL_PRICE_PACKAGE + "." + resources[i].getName().replace(".class", ""));
+//                //判断是否是CalPrice的实现类并且不是CalPrice它本身，满足的话加入到策略列表
+//                if (CalPrice.class.isAssignableFrom(clazz) && clazz != calPriceClazz) {
+//                    calPriceList.add((Class<? extends CalPrice>) clazz);
+//                }
+//            } catch (ClassNotFoundException e) {
+//                e.printStackTrace();
+//            }
+//        }
+//    }
+//
+//    //获取扫描的包下面所有的class文件
+//    private File[] getResources() {
+//        try {
+//            File file = new File(classLoader.getResource(CAL_PRICE_PACKAGE.replace(".", "/")).toURI());
+//            return file.listFiles(new FileFilter() {
+//                public boolean accept(File pathname) {
+//                    if (pathname.getName().endsWith(".class")) {//我们只扫描class文件
+//                        return true;
+//                    }
+//                    return false;
+//                }
+//            });
+//        } catch (URISyntaxException e) {
+//            throw new RuntimeException("未找到策略资源");
+//        }
+//    }
+//
+//    public static CalPriceFactory getInstance() {
+//        return CalPriceFactoryInstance.instance;
+//    }
+//
+//    private static class CalPriceFactoryInstance {
+//
+//        private static CalPriceFactory instance = new CalPriceFactory();
+//    }
+}

src/com/blankj/custom/desingn_pattern/strategy/example/Client.java

@@ -0,0 +1,15 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+public class Client {
+    public static void main(String[] args) {
+        Player player = new Player();
+        player.buy(5000D);
+        System.out.println("玩家需要付钱：" + player.calLastAmount());
+        player.buy(12000D);
+        System.out.println("玩家需要付钱：" + player.calLastAmount());
+        player.buy(12000D);
+        System.out.println("玩家需要付钱：" + player.calLastAmount());
+        player.buy(12000D);
+        System.out.println("玩家需要付钱：" + player.calLastAmount());
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/example/GoldVip.java

@@ -0,0 +1,9 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+@PriceRegion(min=3000)
+public class GoldVip implements CalPrice {
+    @Override
+    public Double calPrice(Double orgnicPrice) {
+        return orgnicPrice  * 0.7;
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/example/Orgnic.java

@@ -0,0 +1,9 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+@PriceRegion(max = 10000)
+public class Orgnic implements CalPrice {
+    @Override
+    public Double calPrice(Double orgnicPrice) {
+        return orgnicPrice;
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/example/Player.java

@@ -0,0 +1,38 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+public class Player {
+    private Double totalAmount = 0D;//客户在鹅厂消费的总额
+    private Double amount = 0D;//客户单次消费金额
+    private CalPrice calPrice = new Orgnic();//每个客户都有一个计算价格的策略，初始都是普通计算，即原价
+
+//    //客户购买皮肤，就会增加它的总额
+//    public void buy(Double amount) {
+//        this.amount = amount;
+//        totalAmount += amount;
+//        if (totalAmount > 30000) {//30000则改为金牌会员计算方式
+//            calPrice = new GoldVip();
+//        } else if (totalAmount > 20000) {//类似
+//            calPrice = new SuperVip();
+//        } else if (totalAmount > 10000) {//类似
+//            calPrice = new Vip();
+//        }
+//    }
+
+    //客户购买皮肤，就会增加它的总额
+    public void buy(Double amount) {
+        this.amount = amount;
+        totalAmount += amount;
+        /* 变化点，我们将策略的制定转移给了策略工厂，将这部分责任分离出去 */
+        calPrice = CalPriceFactory.createCalPrice(this);
+//        calPrice = CalPriceFactory.getInstance().createCalPrice(this);
+    }
+
+    //计算客户最终要付的钱
+    public Double calLastAmount() {
+        return calPrice.calPrice(amount);
+    }
+
+    public Double getTotalAmount() {
+        return totalAmount;
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/example/PriceRegion.java

@@ -0,0 +1,14 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+//这是有效价格区间注解，可以给策略添加有效区间的设置
+@Target(ElementType.TYPE)//表示只能给类添加该注解
+@Retention(RetentionPolicy.RUNTIME)//这个必须要将注解保留在运行时
+public @interface PriceRegion {
+    int max() default Integer.MAX_VALUE;
+    int min() default Integer.MIN_VALUE;
+}

src/com/blankj/custom/desingn_pattern/strategy/example/SuperVip.java

@@ -0,0 +1,9 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+@PriceRegion(min=20000,max=30000)
+public class SuperVip implements CalPrice {
+    @Override
+    public Double calPrice(Double orgnicPrice) {
+        return orgnicPrice  * 0.8;
+    }
+}

src/com/blankj/custom/desingn_pattern/strategy/example/Vip.java

@@ -0,0 +1,9 @@
+package com.blankj.custom.desingn_pattern.strategy.example;
+
+@PriceRegion(max=20000)
+public class Vip implements CalPrice {
+    @Override
+    public Double calPrice(Double orgnicPrice) {
+        return orgnicPrice  * 0.9;
+    }
+}