設計一個線上教育知識付費源碼系統(www.xiaofeifei666.top)。
解決方案:假設我們想要設計一個基本的内容付費閱讀系統并帶小程式，提供以下功能：
•查找知識資料庫并閱讀付費内容；
•使用者成員的建立和擴充；
•基于使用者分級權限管理，并且這個使用者隻能獲權後閱讀。
倉庫完整源碼：zs.xcxyms.top
類OnlineReaderSystem代表程式的主體。我們可以實作這個類，讓它存儲有關所有涉及使用者管理的權限分級的資訊，并重新整理顯示，但這會使這個類變得相當龐大。相反，我們選擇将這些元件拆分成Library、UserManager和Display類。
類:
1、使用者
2、知識
3、UserManager
4、OnlineReaderSystem
代碼如下:
import java.util.HashMap;
/*
* This class represents the system
*/
class OnlineReaderSystem {
private Library library;
private UserManager userManager;
private Display display;
private Book activeBook;
private User activeUser;
public OnlineReaderSystem()
{
userManager = new UserManager();
library = new Library();
display = new Display();
}
public Library getLibrary()
{
return library;
}
public UserManager getUserManager()
{
return userManager;
}
public Display getDisplay()
{
return display;
}
public Book getActiveBook()
{
return activeBook;
}
public void setActiveBook(Book book)
{
activeBook = book;
display.displayBook(book);
}
public User getActiveUser()
{
return activeUser;
}
public void setActiveUser(User user)
{
activeUser = user;
display.displayUser(user);
}
}
/*
* We then implement separate classes to handle the user
* manager, the library, and the display components
*/
/*
* This class represents the Library which is responsible
* for storing and searching the books.
*/
class Library {
private HashMap<Integer, Book> books;
public Library()
{
books = new HashMap<Integer, Book>();
}
public Boolean addBook(int id, String details, String title)
{
if (books.containsKey(id)) {
return false;
}
Book book = new Book(id, details, title);
books.put(id, book);
return true;
}
public Boolean addBook(Book book)
{
if (books.containsKey(book.getId())) {
return false;
}
books.put(book.getId(), book);
return true;
}
public boolean remove(Book b)
{
return remove(b.getId());
}
public boolean remove(int id)
{
if (!books.containsKey(id)) {
return false;
}
books.remove(id);
return true;
}
public Book find(int id)
{
return books.get(id);
}
}
/*
* This class represents the UserManager which is responsible
* for managing the users, their membership etc.
*/
class UserManager {
private HashMap<Integer, User> users;
public UserManager()
{
users = new HashMap<Integer, User>();
}
public Boolean addUser(int id, String details, String name)
{
if (users.containsKey(id)) {
return false;
}
User user = new User(id, details, name);
users.put(id, user);
return true;
}
public Boolean addUser(User user)
{
if (users.containsKey(user.getId())) {
return false;
}
users.put(user.getId(), user);
return true;
}
public boolean remove(User u)
{
return remove(u.getId());
}
public boolean remove(int id)
{
if (users.containsKey(id)) {
return false;
}
users.remove(id);
return true;
}
public User find(int id)
{
return users.get(id);
}
}
/*
* This class represents the Display, which is responsible
* for displaying the book, it's pages and contents. It also
* shows the current user. * It provides the method
* turnPageForward, turnPageBackward, refreshPage etc.
*/
class Display {
private Book activeBook;
private User activeUser;
private int pageNumber = 0;
public void displayUser(User user)
{
activeUser = user;
refreshUsername();
}
public void displayBook(Book book)
{
pageNumber = 0;
activeBook = book;
refreshTitle();
refreshDetails();
refreshPage();
}
public void turnPageForward()
{
pageNumber++;
System.out.println("Turning forward to page no " +
pageNumber + " of book having title " +
activeBook.getTitle());
refreshPage();
}
public void turnPageBackward()
{
pageNumber--;
System.out.println("Turning backward to page no " +
pageNumber + " of book having title " +
activeBook.getTitle());
refreshPage();
}
public void refreshUsername()
{
/* updates username display */
System.out.println("User name " + activeUser.getName() +
" is refreshed");
}
public void refreshTitle()
{
/* updates title display */
System.out.println("Title of the book " +
activeBook.getTitle() + " refreshed");
}
public void refreshDetails()
{
/* updates details display */
System.out.println("Details of the book " +
activeBook.getTitle() + " refreshed");
}
public void refreshPage()
{
/* updated page display */
System.out.println("Page no " + pageNumber + " refreshed");
}
}
/*
* The classes for User and Book simply hold data and
* provide little functionality.
* This class represents the Book which is a simple POJO
*/
class Book {
private int bookId;
private String details;
private String title;
public Book(int id, String details, String title)
{
bookId = id;
this.details = details;
this.title = title;
}
public int getId()
{
return bookId;
}
public void setId(int id)
{
bookId = id;
}
public String getDetails()
{
return details;
}
public void setDetails(String details)
{
this.details = details;
}
public String getTitle()
{
return title;
}
public void setTitle(String title)
{
this.title = title;
}
}
/*
* This class represents the User which is a simple POJO
*/
class User {
private int userId;
private String name;
private String details;
public void renewMembership()
{
}
public User(int id, String details, String name)
{
this.userId = id;
this.details = details;
this.name = name;
}
public int getId()
{
return userId;
}
public void setId(int id)
{
userId = id;
}
public String getDetails()
{
return details;
}
public void setDetails(String details)
{
this.details = details;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
}
// This class is used to test the Application
public class AppTest {
public static void main(String[] args)
{
OnlineReaderSystem onlineReaderSystem = new OnlineReaderSystem();
Book dsBook = new Book(1, "It contains Data Structures", "Ds");
Book algoBook = new Book(2, "It contains Algorithms", "Algo");
onlineReaderSystem.getLibrary().addBook(dsBook);
onlineReaderSystem.getLibrary().addBook(algoBook);
User user1 = new User(1, " ", "Ram");
User user2 = new User(2, " ", "Gopal");
onlineReaderSystem.getUserManager().addUser(user1);
onlineReaderSystem.getUserManager().addUser(user2);
onlineReaderSystem.setActiveBook(algoBook);
onlineReaderSystem.setActiveUser(user1);
onlineReaderSystem.getDisplay().turnPageForward();
onlineReaderSystem.getDisplay().turnPageForward();
onlineReaderSystem.getDisplay().turnPageBackward();
}
}
知識付費源碼系統類圖:聚合和多重性是設計類圖時需要考慮的兩個重要問題。讓我們來詳細了解一下。
聚合,
聚合隻是表示一種關系，其中一件事可以獨立于其他事存在。它意味着在定義類時建立或組合不同的抽象。聚合表示為類圖中關系的一部分。在下面的圖中，我們可以看到聚合是由一個指向超類的菱形末端的邊表示的。“圖書管理系統”是由各種類組成的超類。
這些類是User、Book和Librarian。此外，對于“Account”類，“User”是一個超類。所有這些，共享一種關系，這些關系被稱為聚合關系。
多重性,
多重性意味着一個類的元素數量與另一個類相關聯。這些關系可以是一對一、多對多、多對一或一對多。用來表示我們使用的一個元素1，表示我們使用的零元素0，以及我們使用的許多元素＊． 我們可以從圖表中看到;許多使用者與表示的許多書相關聯＊這表示多對多類型的關系。一個使用者隻有一個用1表示的帳戶，這表示a一對一的類型的關系。
知識付費系統類圖簡單地描述了知識管理系統類的結構、屬性、方法或操作、對象之間的關系。
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版權聲明：本文為CSDN部落客「scxcyzm」的原創文章，遵循CC 4.0 BY-SA版權協定，轉載請附上原文出處連結及本聲明。
原文連結：https://blog.csdn.net/scxcyzm/article/details/123729468
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