修改项目目录

src/chapter3/demo31/PayBooks.java

@@ -0,0 +1,64 @@
+package chapter3.demo31;
+
+import java.util.Scanner;
+
+public class PayBooks {
+    public static void main(String[] args) {
+        Book[] books = new Book[3];
+        // 模拟从数据库中读取图书信息并输出
+        outBooks(books);
+        // 顾客购买图书
+        Order order = purchase(books);
+        // 输出订单信息
+        outOrder(order);
+    }
+
+    // 顾客购买图书
+    public static Order purchase(Book[] books) {
+        Order order = new Order("00001");
+        OrderItem item = null;
+        Scanner in = new Scanner(System.in);
+
+        for (int i = 0; i < 3; i++) {
+            System.out.println("请输入图书编号选择图书：");
+            int cno = in.nextInt();
+            System.out.println("请输入购买图书数量：");
+            int pnum = in.nextInt();
+            item = new OrderItem(books[cno - 1], pnum);
+            order.setItem(item, i);
+            System.out.println("请继续购买图书。");
+        }
+        in.close();
+        return order;
+    }
+
+    // 输出订单信息
+    public static void outOrder(Order order) {
+        System.out.println("\n===================图书订单===================");
+        System.out.println("图书订单号：" + order.getOrderId());
+        System.out.println("图书名称\t购买数量\t图书单价");
+        System.out.println("--------------------------------------");
+        OrderItem[] items = order.getItems();
+        for (OrderItem item : items) {
+            System.out.println(
+                    item.getBook().getName() + "\t" + item.getNum() + "\t" + item.getBook().getPrice());
+        }
+        System.out.println("---------------------------------------");
+        System.out.println("订单总额：\t\t" + order.getTotal());
+    }
+
+    // 模拟从数据库中读取图书信息并输出
+    public static void outBooks(Book[] books) {
+        books[0] = new Book(1, "Java教程", 30.6, 30);
+        books[1] = new Book(2, "JSP教程", 42.1, 40);
+        books[2] = new Book(3, "SSH架构", 47.3, 15);
+        System.out.println("===================图书列表===================");
+        System.out.println("图书编号\t图书名称\t\t图书单价\t库存数量");
+        System.out.println("---------------------------------------");
+        for (int i = 0; i < books.length; i++) {
+            System.out.println(
+                    i + 1 + "\t" + books[i].getName() + "\t" + books[i].getPrice() + "\t" + books[i].getStorage());
+        }
+        System.out.println("---------------------------------------");
+    }
+}