使用Iterator遍历hashMap

  1 package com.ls.service;
  2
  3 import java.util.*;
  4 import com.ls.domain.Book;
  5 import com.sun.media.sound.AlawCodec;
  6 public class MyCartService {
  7
  8     HashMap<String,Book> hm=new HashMap<String, Book>();
  9     //Add2 books
 10
 11     public void addBook(String id){
 12         if(hm.containsKey(id)){
 13         Book book =hm.get(id);
 14         int shoppingNum=book.getShoppingNum();
 15         book.setShoppingNum(shoppingNum+1);
 16         }else{
 17         hm.put(id, new BookService().getBookById(id));
 18         }
 19     }
 20
 21
 22
 23     //Add books
 24     public void addBook(String id,Book book){
 25         if(hm.containsKey(id)){
 26         System.out.println("hm.containsKey(id)");
 27         int shoppingNum=book.getShoppingNum();
 28         book.setShoppingNum(shoppingNum+1);
 29         }else{
 30             System.out.println("xxx");
 31             hm.put(id, book);
 32         }
 33     }
 34
 35
 36
 37     //Delete books
 38     public void deleteBook(String id){
 39         hm.remove(id);
 40     }
 41
 42
 43
 44
 45     //Update books/myCart   numbers
 46
 47     public void updateBook(String id,String num){
 48         //取出ID对应book
 49         Book book =hm.get(id);
 50         book.setShoppingNum(Integer.parseInt(num));
 51
 52     }
 53
 54
 55     //显示购物车中的所有商品信息
 56     public ArrayList showMyCart(){
 57
 58                   ArrayList<Book> alBook=new ArrayList<Book>();
 59
 60     //遍历hashMap
 61
 62
 63     Iterator iterator =hm.keySet().iterator();
 64     while(iterator.hasNext()){
 65     //key
 66     String id=(String)iterator.next();
 67     //Book
 68     Book book=hm.get(id);
 69     alBook.add(book);
 70         }
 71         return alBook;
 72     }
 73
 74     //返回该购物车的总价
 75     public float getToatlPrice(){
 76         float totalPrice=0.0f;
 77
 78         //得到总价格
 79         ArrayList<Book> al =new ArrayList<Book>();
 80
 81         Iterator iterator=hm.keySet().iterator();
 82         while(iterator.hasNext()){
 83             //取出书号
 84
 85             String bookId=(String)iterator.next();
 86             //取出书号对应的bookbean
 87             Book book=hm.get(bookId);
 88     totalPrice+=book.getPrice()*book.getShoppingNum();
 89
 90         }
 91
 92
 93         return totalPrice;
 94     }
 95
 96     //Clear books/myCart
 97     public void cleanBook(){
 98         hm.clear();
 99     }
100
101
102 }