Java实现简单图书馆管理系统

2023-08-08 06:18| 来源: 网络整理| 查看: 265

编写图书馆管理系统源码https://github.com/Hu1Wence/Learn_Java/tree/master/BookManage 思路

要编写这个程序我们首相要清楚这个程序中有哪些对象,不考虑复杂情况，基本的对象有三个：

书用户

那么我们就分别讨论这三个对象有哪些属性和有哪些动作。

书籍它会有书名，编号(id)，作者，类别，价格，是否被借这些简单的属性用户包括：管理员和普通用户，管理员它会有姓名，增加书籍，删除书籍，查找书籍，打印所有书籍信息，退出系统这些简单属性。普通用户它会有姓名，查找书籍，借阅书籍，归还书籍，退出系统这些简单的属性。

我们把这三个对象分别放入三个包中，这样在分别完成这些对象中所需的动作(方法)。我们书籍包中的代码：

package book; public class Book { private String name; private String id; private String author; private String type; private int price; private boolean isBorrow; public Book(String name, String id, String author, String type, int price, boolean isBorrow) { this.name = name; this.id = id; this.author = author; this.type = type; this.price = price; this.isBorrow = isBorrow; } public String getId() { return id; } public boolean isBorrow() { return isBorrow; } public void setBorrow(boolean borrow) { isBorrow = borrow; } public String getName() { return name; } @Override public String toString() { return "Book{" + "name='" + name + '\'' + ", id='" + id + '\'' + ", author='" + author + '\'' + ", type='" + type + '\'' + ", price=" + price + ", isBorrow=" + isBorrow + '}'; } }

同时创建一个类似顺序表的书籍数组保存书籍。

package book; public class BookList { private Book[] books = new Book[100]; private int size; public BookList() { books[0] = new Book("金瓶梅", "001", "兰陵笑笑生","古典名著", 100, false); books[1] = new Book("水浒传", "002", "施耐庵","古典名著", 100, false); books[2] = new Book("西游记", "003", "吴承恩","古典名著", 100, false); size = 3; } public int getSize() { return size; } public void setSize(int size) { this.size = size; } public Book getBook(int index) { return books[index]; } public void setBooks(int index, Book book) { books[index] = book; } }

我们将用所有的操作方法放入operation包中，所有的方法都用接口来实现，这样我们就避免了使用一大堆的 if else

接口：

package operation; import book.BookList; public interface IOperation { void work(BookList bookList); }

增加新书籍：

package operation; import book.Book; import book.BookList; import java.util.Scanner; public class AddBookOperation implements IOperation{ @Override public void work(BookList bookList) { System.out.println("新增一本书籍!"); System.out.println("请输入新增书籍的书名: "); Scanner scanner = new Scanner(System.in); String name = scanner.next(); System.out.println("请输入新增书籍的id: "); String id = scanner.next(); System.out.println("请输入新增书籍的作者: "); String author = scanner.next(); System.out.println("请输入新增书籍的类型: "); String type = scanner.next(); System.out.println("请输入新增书籍的价格: "); int price = scanner.nextInt(); Book book = new Book(name, id, author, type, price, false); bookList.setBooks(bookList.getSize(), book); bookList.setSize(bookList.getSize() + 1); } }

删除书籍：

package operation; import book.Book; import book.BookList; import java.util.Scanner; public class DeleteBookOperation implements IOperation { @Override public void work(BookList bookList) { System.out.println("删除书籍!"); System.out.println("请输入您想要删除书籍的id: "); Scanner scanner = new Scanner(System.in); String id = scanner.next(); int i = 0; for (; i break; } } if (i >= bookList.getSize()) { System.out.println("未找到要找的书籍!"); return; } Book lastBook = bookList.getBook(bookList.getSize() - 1); bookList.setBooks(i, lastBook); bookList.setSize(bookList.getSize() - 1); System.out.println("删除成功!"); } }

查找书籍：

package operation; import book.Book; import book.BookList; import java.util.Scanner; public class FindOperation implements IOperation { @Override public void work(BookList bookList) { System.out.println("查找书籍!"); System.out.println("请输入要查找书籍的书名: "); Scanner scanner = new Scanner(System.in); String name = scanner.next(); int count = 0; for (int i = 0; i System.out.println(book); count++; } } if (count == 0) { System.out.println("没找到此书籍!"); } else { System.out.println("共找到 " + count + " 本相同书籍!"); } } }

借阅书籍：

package operation; import book.Book; import book.BookList; import java.util.Scanner; public class BorrowOperation implements IOperation { @Override public void work(BookList bookList) { System.out.println("借阅书籍!"); System.out.println("请输入要借阅的书籍的id: "); Scanner scanner = new Scanner(System.in); String id = scanner.next(); for (int i = 0; i continue; } if (book.isBorrow()) { System.out.println("此书已经被借走了!"); break; } book.setBorrow(true); System.out.println("借阅成功"); } } }

归还书籍：

package operation; import book.Book; import book.BookList; import java.util.Scanner; public class ReturnOperation implements IOperation { @Override public void work(BookList bookList) { System.out.println("归还书籍!"); System.out.println("请输入要归还书籍的id: "); Scanner scanner = new Scanner(System.in); String id = scanner.next(); int i = 0; for ( ; i continue; } if (!book.isBorrow()) { System.out.println("这本书未借出去,归还失败!"); } book.setBorrow(false); } } }

打印所有书籍信息：

package operation; import book.BookList; public class PrintAllOperation implements IOperation { @Override public void work(BookList bookList) { for (int i = 0; i @Override public void work(BookList bookList) { System.out.println("GoodBye!"); System.exit(0); } }

我们用户中先创建一个抽象的用户，再将不同用户通过实现这个抽象的用户来实现不同用户的操作权限。我们用户包中的代码抽象的用户代码：

package user; import book.BookList; import operation.IOperation; abstract public class User { protected String name; protected IOperation[] operations; public User(String name) { this.name = name; } abstract public int menu(); public void doOperation(int choice, BookList bookList) { operations[choice].work(bookList); } }

管理员用户：

package user; import book.BookList; import operation.*; import java.util.Scanner; public class Admin extends User{ public Admin(String name) { super(name); operations = new IOperation[] { new ExitOperation(), new AddBookOperation(), new DeleteBookOperation(), new FindOperation(), new PrintAllOperation(), }; } @Override public int menu() { System.out.println("============"); System.out.println("hello " + name); System.out.println("1. 增加书籍"); System.out.println("2. 删除书籍"); System.out.println("3. 查找书籍"); System.out.println("4. 打印所有信息"); System.out.println("0. 退出"); System.out.println("============"); System.out.println("请输入您的选择: "); Scanner scanner = new Scanner(System.in); int choice = scanner.nextInt(); return choice; } }

普通用户：

package user; import operation.*; import java.util.Scanner; public class NormalUser extends User { public NormalUser(String name) { super(name); operations = new IOperation[] { new ExitOperation(), new FindOperation(), new BorrowOperation(), new ReturnOperation(), }; } @Override public int menu() { System.out.println("============"); System.out.println("hello " + name); System.out.println("1. 查找图书"); System.out.println("2. 借阅图书"); System.out.println("3. 归还图书"); System.out.println("0. 退出"); System.out.println("============"); System.out.println("请输入您的选择: "); Scanner scanner = new Scanner(System.in); int choice = scanner.nextInt(); return choice; } }

这样就完成了一个简单的图书馆管理系统。

这是测试类代码块

import book.BookList; import user.Admin; import user.NormalUser; import user.User; import java.util.Scanner; public class Test { public static void main(String[] args) { BookList bookList = new BookList(); User user = login(); while (true) { int choice = user.menu(); user.doOperation(choice, bookList); } } public static User login() { Scanner scanner = new Scanner(System.in); System.out.println("欢迎来到图书管理系统!"); System.out.println("请输入您的姓名: "); String name = scanner.next(); System.out.println("请输入您的用户选项: 1 -> 管理员 2 -> 普通用户"); int role = scanner.nextInt(); if (role == 1) { return new Admin(name); } else { return new NormalUser(name); } } }

新增登录、注册模块创建dao包

我们的用户User类，包含用户名，密码

package dao; public class User { String username; String password; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }

UserDao包含登录和注册

package dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; public class UserDao { //注册 public void login(User user) { Connection connection = DBUtil.getConnection(); PreparedStatement statement = null; String sql = "insert into user values(?, ?)"; try { statement = connection.prepareStatement(sql); statement.setString(1, user.getUsername()); statement.setString(2, user.getPassword()); int ret = statement.executeUpdate(); if (ret != 1) { System.out.println("当前数据库执行插入数据出错"); return; } } catch (SQLException throwables) { throwables.printStackTrace(); } finally { DBUtil.close(connection, statement, null); } } //登录 public int enter(String username, String password) { List list = new ArrayList(); Connection connection = DBUtil.getConnection(); String sql = "select username, password from user where username = ?"; PreparedStatement statement = null; ResultSet resultSet = null; int ret = 0; try { statement = connection.prepareStatement(sql); statement.setString(1, username); while (resultSet.next()) { String pass = resultSet.getString(password); list.add(pass); } if (list.contains(password)) { ret = 1; } } catch (SQLException throwables) { throwables.printStackTrace(); } finally { DBUtil.close(connection, statement, resultSet); } return ret; } }

DBUtil实现连接数据库

package dao; import java.sql.*; public class DBUtil { private static final String URL = "jdbc:mysql://localhost:3306/java_github_crawler"; private static final String USERNAME = "root"; private static final String PASSWORD = "123456"; private static Connection conn = null; static{ try { //1.加载驱动程序 Class.forName("com.mysql.jdbc.Driver"); //2. 获得数据库连接 conn = DriverManager.getConnection(URL, USERNAME, PASSWORD); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } } public static Connection getConnection(){ return conn; } //释放资源 public static void close(Connection connection, Statement statement, ResultSet resultSet) { try { if (resultSet != null) { resultSet.close(); } if (statement != null) { statement.close(); } if (connection != null) { connection.close(); } } catch (Exception e) { throw new RuntimeException("释放数据库资源失败", e); } } }

新的测试类：

import book.BookList; import dao.UserDao; import user.Admin; import user.NormalUser; import user.User; import java.util.Scanner; public class Test { public static void main(String[] args) { BookList bookList = new BookList(); User user = login(); if (user == null) { return; } while (true) { int choice = user.menu(); user.doOperation(choice, bookList); } } public static User login() { Scanner scanner = new Scanner(System.in); System.out.println("欢迎来到图书管理系统!"); dao.User user = new dao.User(); System.out.println("请输入您的用户选项: 1 -> 注册 2 -> 登录"); int role = scanner.nextInt(); UserDao userDao = new UserDao(); boolean isEnter = false; if (role == 1) { System.out.println("请输入用户名: "); user.setUsername(scanner.nextLine()); System.out.println("请输入密码: "); user.setPassword(scanner.nextLine()); userDao.login(user); } else { for (int i = 3; i >= 0; i--) { System.out.println("请输入用户名: "); String username = scanner.nextLine(); System.out.println("请输入密码: "); String password = scanner.nextLine(); int ret = userDao.enter(username, password); if (ret != 1) { System.out.println("登录失败,您还有 " + i + "次机会"); } else { System.out.println("登录成功"); isEnter = true; break; } } } if (!isEnter) { return null; } String name = user.getUsername(); System.out.println("请输入您的用户选项: 1 -> 管理员 2 -> 普通用户"); if (role == 1) { return new Admin(name); } else { return new NormalUser(name); } } }

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