字符串的 ArrayList 和另一个 arraylist

Question

所以我正在制作一个程序来管理一家书店，这是一个示例，说明应该如何处理以下主要内容：

        bookStore bookStore = new bookStore("Lelo");
        book l1 = new TecnicalBook("H. Schildt", "\"Java: The Complete Reference\"", 80, "Computer Science- Java");
        bookStore.addBook(l1);
        book l2= new AdventureBook("A. Christie", "\"The Man in the Brown Suit\"", 75, 14);
        bookStore.addBook(l2);
                
        
        Client c1 = new Premium("B. Antunes", "antunes@books.com");
        bookStore.addClient(c1);
        Client c2 = new Frequent("A. Oliveira", "oliveira@books.com");
        bookStore.addClient(c2);
        System.out.println("Initial stock:");
        bookStore.showBooks();
        bookStore.sale(l1, c1);
        System.out.println("Stock after selling:");
        bookStore.showBooks();
        System.out.println("Sales Volume:"+bookStore.SalesVolume);        
        bookStore.showClientsBooks(c1);

应该显示这个结果：

Initial stock:
Author:H. Schildt   Title:"Java: The Complete Reference"   Base Price:80.0
Author:A. Christie   Title:"The Man in the Brown Suit"   Base Price:75.0
B. Antunes bought "Java: The Complete Reference", Tecnical Book of Computer Science- Java, for 72.0
Stock after selling:
Author:A. Christie   Title:"The Man in the Brown Suit"   Base Price:75.0
Sales Volume:72.0
B. Antunes bought: "UML Distilled". "The Man in the Brown Suit".

我唯一不能做的是最后一行，显示每个客户购买的产品，我正在考虑制作一个 class，其中包含一个带有客户名称的字符串和一个数组列表预订 class，然后为每个客户提供一个 class 的数组列表，但我不确定如何制作它，可能有更好的方法，谢谢

编辑：我有这个 classes： class本书 class 技术书籍扩展书籍 class 冒险书扩展书本

class 客户端 class 常规扩展客户端 class 经常扩展客户端 class 高级扩展客户

而且我有书店 class，其中有书籍和客户对象的数组列表。

Answer 1

在每个 class 中覆盖 toString 很重要。然后，当您打印 class 的实例时，将打印字符串而不是一些奇怪的值。

此方法还允许您一次添加所有图书或单独添加图书。

此 class 尚未经过测试，但应该可以让您了解如何进行。

class Client {
  String name;
  private List<Book> clientBooks = new ArrayList<>();
  public Client(String name) {
     this.name = name;
  }

  public addBooks(List<Book> books) {
      clientBooks.addAll(books);
  }

  public void addBook(Book bk) {
      clientBooks.add(bk);
  }

  public String toString() {
     StringBuilder sb = new StringBuilder(name).append(":");
     // add either the entire toString for book here or just selected
     // items like the title.  It's up to you.
     for (Book b :clientBooks) {
        sb.append(b.toString()).append(", ");
     }
     
     return sb.toString().substring(0,sb.length()-2);
  }
}

Answer 2

您可以将图书列表添加到您的客户 class 以跟踪销售情况：

class Client {

    ...

    private List<Book> books;

    ClientBooks(Client client) {
        ...

        this.books = new ArrayList<>();
    }

    public void addBook(Book book) {
        this.books.add(book);
    }

    public void printBooks() {
        for (Book book : this.books) {
            System.out.println(book);
        }
    }
}

卖书可以这样实现：

List<Client> clients = ...

String buyer = ...
Book book = ...

for(Client client : clients) {
    if (client.getName().equals(buyer)) {
        client.addBook(book);
    }
}

字符串的 ArrayList 和另一个 arraylist

ArrayList of string and another arraylist

java

oop

polymorphism

arraylist

hierarchy