外观模式，改造前

src/main/java/top/fjy8018/designpattern/pattern/structural/facade/GiftExchangeService.java

@@ -0,0 +1,49 @@
+package top.fjy8018.designpattern.pattern.structural.facade;
+
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * 外观类——礼物兑换逻辑
+ * <p>
+ * 该服务定义了与各个子系统交互的逻辑，业务系统无需知道与内部子系统的交互逻辑，符合迪米特法则
+ *
+ * @author F嘉阳
+ * @date 2020/2/28 10:44
+ */
+@Slf4j
+public class GiftExchangeService {
+
+    private PointPaymentService pointPaymentService;
+
+    private QualifyService qualifyService;
+
+    private ShippingService shippingService;
+
+    public void setPointPaymentService(PointPaymentService pointPaymentService) {
+        this.pointPaymentService = pointPaymentService;
+    }
+
+    public void setQualifyService(QualifyService qualifyService) {
+        this.qualifyService = qualifyService;
+    }
+
+    public void setShippingService(ShippingService shippingService) {
+        this.shippingService = shippingService;
+    }
+
+    /**
+     * 系统交互逻辑
+     *
+     * @param pointGift
+     */
+    public void giftExchange(PointGift pointGift) {
+        if (qualifyService.isAvalible(pointGift)) {
+            // 资格校验通过
+            if (pointPaymentService.pay(pointGift)) {
+                // 如果积分支付成功
+                String shippingOrderNo = shippingService.shipGift(pointGift);
+                log.info("物流系统下单成功，订单号为{}", shippingOrderNo);
+            }
+        }
+    }
+}

src/main/java/top/fjy8018/designpattern/pattern/structural/facade/PointGift.java

@@ -0,0 +1,17 @@
+package top.fjy8018.designpattern.pattern.structural.facade;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+/**
+ * 外观模式又叫门面模式,提供了一个统一的接口,用来访问子系统中的一群接口
+ * 积分礼物
+ *
+ * @author F嘉阳
+ * @date 2020/2/28 10:33
+ */
+@Getter
+@AllArgsConstructor
+public class PointGift {
+    private String name;
+}

src/main/java/top/fjy8018/designpattern/pattern/structural/facade/PointPaymentService.java

@@ -0,0 +1,19 @@
+package top.fjy8018.designpattern.pattern.structural.facade;
+
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * 积分支付校验子系统
+ *
+ * @author F嘉阳
+ * @date 2020/2/28 10:37
+ */
+@Slf4j
+public class PointPaymentService {
+
+    public boolean pay(PointGift pointGift) {
+        // 扣减积分逻辑
+        log.info("支付礼物 {} 积分成功", pointGift.getName());
+        return true;
+    }
+}

src/main/java/top/fjy8018/designpattern/pattern/structural/facade/QualifyService.java

@@ -0,0 +1,24 @@
+package top.fjy8018.designpattern.pattern.structural.facade;
+
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * 积分校验子系统
+ *
+ * @author F嘉阳
+ * @date 2020/2/28 10:34
+ */
+@Slf4j
+public class QualifyService {
+
+    /**
+     * 模拟积分校验逻辑
+     *
+     * @param pointGift
+     * @return
+     */
+    public boolean isAvalible(PointGift pointGift) {
+        log.info("校验礼物 {} 通过，积分校验通过，库存通过", pointGift.getName());
+        return true;
+    }
+}

src/main/java/top/fjy8018/designpattern/pattern/structural/facade/ShippingService.java

@@ -0,0 +1,25 @@
+package top.fjy8018.designpattern.pattern.structural.facade;
+
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * 物流子系统
+ *
+ * @author F嘉阳
+ * @date 2020/2/28 10:39
+ */
+@Slf4j
+public class ShippingService {
+
+    /**
+     * 返回物流运单号
+     *
+     * @param pointGift
+     * @return
+     */
+    public String shipGift(PointGift pointGift) {
+        // 物流系统对接逻辑
+        log.info("礼物 {} 进入物流系统", pointGift.getName());
+        return "123456";
+    }
+}

src/test/java/top/fjy8018/designpattern/pattern/structural/decorator/BattercakeTest.java

@@ -1,4 +1,4 @@
-package top.fjy8018.designpattern.pattern.structural.decorator.before;
+package top.fjy8018.designpattern.pattern.structural.decorator;
 
 import lombok.extern.slf4j.Slf4j;
 import org.junit.jupiter.api.Test;
@@ -7,8 +7,6 @@ import top.fjy8018.designpattern.pattern.structural.decorator.after.AbstractBatt
 import top.fjy8018.designpattern.pattern.structural.decorator.after.EggBattercake;
 import top.fjy8018.designpattern.pattern.structural.decorator.after.SausageBattercake;
 
-import static org.junit.jupiter.api.Assertions.*;
-
 @Slf4j
 class BattercakeTest {
 

src/test/java/top/fjy8018/designpattern/pattern/structural/facade/GiftExchangeServiceTest.java

@@ -0,0 +1,24 @@
+package top.fjy8018.designpattern.pattern.structural.facade;
+
+import lombok.extern.slf4j.Slf4j;
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author F嘉阳
+ * @date 2020/2/28 10:53
+ */
+@Slf4j
+class GiftExchangeServiceTest {
+
+    @Test
+    void giftExchange() {
+        PointGift pointGift = new PointGift("手环");
+        // 注入服务
+        GiftExchangeService exchangeService = new GiftExchangeService();
+        exchangeService.setPointPaymentService(new PointPaymentService());
+        exchangeService.setQualifyService(new QualifyService());
+        exchangeService.setShippingService(new ShippingService());
+        // 兑换
+        exchangeService.giftExchange(pointGift);
+    }
+}