外观模式

Author: anxpp

src/com/anxpp/designpattern/facade/Discount.java

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+package com.anxpp.designpattern.facade;
+//计算优惠
+public class Discount {
+	int getDiscount(String discountCode){
+		return Math.abs(discountCode.hashCode())%3;
+	}
+}

src/com/anxpp/designpattern/facade/FinalPrice.java

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+package com.anxpp.designpattern.facade;
+//计费子系统
+public class FinalPrice {
+	ProductPrice productPrice;
+	Postage postage;
+	Discount discount;
+	public FinalPrice(){
+		productPrice = new ProductPrice();
+		postage = new Postage();
+		discount = new Discount();
+	}
+	int getFinalPrice(String product,String addr,String discountCode){
+		return productPrice.getPrice(product)+postage.getPostage(addr)-discount.getDiscount(discountCode);
+	}
+}

src/com/anxpp/designpattern/facade/Postage.java

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+package com.anxpp.designpattern.facade;
+//计算邮费
+public class Postage {
+	int getPostage(String addr){
+		return Math.abs(addr.hashCode())%20+6;//模拟邮费计算
+	}
+}

src/com/anxpp/designpattern/facade/ProductPrice.java

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+package com.anxpp.designpattern.facade;
+//获取商品价格
+public class ProductPrice {
+	int getPrice(String product){
+		return Math.abs(product.hashCode());//模拟获取商品价格
+	}
+}

src/com/anxpp/designpattern/facade/ProductSalesman.java

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+package com.anxpp.designpattern.facade;
+//外观
+public enum ProductSalesman {
+	instance;
+	Stock stock = new Stock();
+	FinalPrice finalPrice = new FinalPrice();
+	Object buySomething(String product,String addr,String discountCode){
+		if(!stock.hasStock(product))
+			return "库存不足";
+		int price = finalPrice.getFinalPrice(product, addr, discountCode);
+		return "订单信息:" + product + "-" + addr + "-"  + discountCode + "-"  + price;
+	}
+}

src/com/anxpp/designpattern/facade/Stock.java

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+package com.anxpp.designpattern.facade;
+
+import java.util.Random;
+//库存子系统
+public class Stock {
+	boolean hasStock(String product){
+		return new Random().nextInt(Math.abs(product.hashCode()))>0;//模拟是否还有库存
+	}
+}

src/com/anxpp/designpattern/facade/TestUse.java

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+package com.anxpp.designpattern.facade;
+public class TestUse {
+	public static void main(String args[]){
+		Object info = ProductSalesman.instance.buySomething("银河飞船", "地球", "K1234523");
+		System.out.println(info);
+	}
+}

src/com/anxpp/designpattern/facade/package-info.java

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+/**
+ * @author Administrator
+ * 外观模式
+ */
+package com.anxpp.designpattern.facade;