《JAVA程序设计》实验报告(DOC)(7)

所遇问题 及 解决办法 shop.addBooks(); //购物车中加东西 HashMap book4=(HashMap)shop.getBook3(); shop.getSum(book4); //购物车算总价 } } While 条件写错，找了好久。 package unit7; 调试后的public class Book { 程序代码 private String name; private double singlePrice; public String getName() { return name; } public double getSinglePrice() { return singlePrice; } public void setName(String name) { this.name = name; } public void setSinglePrice(double singlePrice) { this.singlePrice = singlePrice; } } package unit7; public class Books { Book book; private int num; public Book getBook() { return book; } public int getNum() { return num; } public void setBook(Book book) { this.book = book; } public void setNum(int num) { this.num = num; } } package unit7; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Scanner; public class ShopCart { private Map book3 = new HashMap(); //每个购物车一个单独的HashMap放东西 public Map getBook3() { // 返回一个购物车中int MaxOrder = 2; int order = 1; 的HashMap public void addBooks() { // 向购物车中的HashMap添 } return book3; 加Books对象，数目不大于MaxOrder while (order <= MaxOrder) { System.out.println(\请输入书名回车结束\ } } Scanner sc1 = new Scanner(System.in); String str = sc1.next(); System.out.println(\请输入该书单价回车结束\Scanner sc2 = new Scanner(System.in); double dou = sc2.nextDouble(); System.out.println(\请输入该书购买数目回车结束\Scanner sc3 = new Scanner(System.in); int i = sc3.nextInt(); Books book1 = new Books(); Book book2 = new Book(); book2.setName(str); book2.setSinglePrice(dou); book1.setBook(book2); book1.setNum(i); book3.put(order, book1); order++; public void getSum(HashMap bookss) {//取得购物车HashMap中的信息算出总价格 double sum = 0.0; Books book5 = new Books(); for (Iterator iterator = bookss.keySet().iterator(); iterator.hasNext();) { book5 = (Books)iterator.next(); sum += (book5.getNum()) * (book5.getBook().getSinglePrice()); } package unit7; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.Scanner; public class ShopCartDemo { public static void main(String[] args) { ShopCart shop=new ShopCart();//新建一个购物车 } } System.out.println(sum);