图书馆管理系统

正文开始@Assassin

1. 整合性实践简介：

利用类，抽象类，封装，继承，多态，接口等知识点进行一个简单的小项目练习。

2. 核心需求：

• 1.简单的登录
• 2.管理端:
  • 整理书籍(该功能为可扩展功能)
  • 查阅书籍
  • 增加书籍
  • 删除书籍
  • 打印书籍列表
  • 退出
• 3.用户端:
  • 查询书籍
  • 借阅书籍
  • 归还书籍
  • 退出

3. 类的设计：

3.1 创建图书相关的类：

先创建 package book，再创建 Book类, 表示一本书

package com.haut.iot.book;public class Book {private String bookName; //书名private String author; //作者private double price; //价格private String type; //类型private boolean isBorrowed = false; //是否被借出//构造方法，初始化属性public Book(String bookName, String author, double price, String type) {this.bookName = bookName;this.author = author;this.price = price;this.type = type;}public String getBookName() {return bookName;}public void setBookName(String bookName) {this.bookName = bookName;}public String getAuthor() {return author;}public void setAuthor(String author) {this.author = author;}public double getPrice() {return price;}public void setPrice(double price) {this.price = price;}public String getType() {return type;}public void setType(String type) {this.type = type;}public boolean isBorrowed() {return isBorrowed;}public void setBorrowed(boolean borrowed) {isBorrowed = borrowed;}@Overridepublic String toString() { //重写toString方法return "Book{" +"bookName='" + bookName + '\'' +", author='" + author + '\'' +", price=" + price +", type='" + type + '\'' +", isBorrowed=" + isBorrowed +'}';}
}

创建 BookList 类, 用来保存 N本书

package com.haut.iot.book;public class BookList {private Book[] books = new Book[100]; //books数组存储书籍private int usedSize = 0; //已经使用过的大小//设置几个初始值, 方便后续测试.public BookList() {books[0] = new Book("三国演义", "罗贯中", 50, "小说");books[1] = new Book("水浒传", "施耐庵", 88, "小说");books[2] = new Book("西游记", "吴承恩", 100, "小说");this.usedSize = 3; //将useSize置为3}public Book getBook(int pos) { //get bookreturn books[pos];}public void setBook(int pos, Book book) { //set bookbooks[pos] = book;}public int getUsedSize() { //get usedSizereturn usedSize;}public void setUsedSize(int usedSize) { // set usedSizethis.usedSize = usedSize;}
}

3.2 创建操作相关的类：

先创建 package operation，再创建一个IOperation接口：

package com.haut.iot.operation;import com.haut.iot.book.BookList; //导包public interface IOperation { //接口void work(BookList bookList);//抽象方法
}

接下来创建一组操作类, 每个类对应一个用户的动作：

• AddOperation
• DeleteOperation
• FindOperation
• RemoveOperation
• DisplayOperation
• BorrowOperation
• ReturnOperation
• ExitOperation

先把空类创建好, 不着急实现细节。
抽象出 Operation 的好处：让操作和操作之间低耦合，让操作和用户之间低耦合

3.3 创建用户相关的类：

先创建 package user包，再创建 User 类, 这是一个抽象类：

package com.haut.iot.user;import com.haut.iot.book.BookList;
import com.haut.iot.operation.IOperation;// User类是一个抽象类, 每个子类需要做两件事情
// 1. 初始化对应的操作数组
// 2. 实现 Menu 菜单
public abstract class User {protected String name; //姓名protected IOperation[] operations;public User(String name) {this.name = name;}//显示菜单public abstract int showMenu();//根据用户选项执行操作public void doOperation(BookList bookList, int choice) {this.operations[choice].work(bookList);}
}

创建普通用户 NormalUser 类, 是 User 的子类：

package com.haut.iot.user;import com.haut.iot.operation.*;import java.util.Scanner;public class NormalUser extends User {public NormalUser(String name) { //构造方法super(name); //帮助父类先完成构造this.operations = new IOperation[] { //初始化操作数组new ExitOperation(), //0 退出new FindOperation(), //1 查找new BorrowOperation(), //2 借阅new ReturnOperation() //3 归还};}@Overridepublic int showMenu() {System.out.println("===========================");System.out.println("hello " + this.name + " 欢迎来到图书管理系统~");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.退出系统");System.out.println("===========================");Scanner scanner = new Scanner(System.in);int choice = scanner.nextInt();return choice; //返回选择}
}

创建管理员用户 Admin 类，也是User类的子类：

package com.haut.iot.user;import com.haut.iot.operation.*;import java.util.Scanner;public class Admin extends User{public Admin(String name) { //构造方法super(name); //帮助父类先完成构造方法this.operations = new IOperation[] { //初始化操作数组new ExitOperation(), //0 退出new FindOperation(), //1 查找new AddOperation(), //2 添加new DeleteOperation(), //3 删除new DisplayOperation() //4 显示};}@Overridepublic int showMenu() {System.out.println("===========================");System.out.println("hello " + this.name + " 欢迎来到图书管理系统~");System.out.println("1.查找图书");System.out.println("2.新增图书");System.out.println("3.删除图书");System.out.println("4.显示所有图书");System.out.println("0.退出系统");System.out.println("===========================");Scanner scanner = new Scanner(System.in);int choice = scanner.nextInt();return choice; //返回选择}
}

3.4 进行代码整合：

创建 TestMain 类和 main 方法, 搭建整体逻辑：

package com.haut.iot;import com.haut.iot.book.BookList;
import com.haut.iot.user.Admin;
import com.haut.iot.user.NormalUser;
import com.haut.iot.user.User;import java.util.Scanner;public class TestMain {public static void main(String[] args) {//1.准备书籍BookList bookList = new BookList();//2.登录User user = login();//向上转型//主循环while (true) {int choice = user.showMenu();//选择是几，就可以对应哪个方法user.doOperation(bookList, choice);//动态绑定}}public static User login() {Scanner scanner = new Scanner(System.in);System.out.println("Please input your name :>");String name = scanner.nextLine();System.out.println("Please enter your identity(1.Admin 2.NormalUser) :>");int choice = scanner.nextInt();if (choice == 1) { //选择是1，则为管理员，反之则为普通用户return new Admin(name);} else {return new NormalUser(name);}}
}

4. 具体实现Operation：

4.1 AddOperation：

package com.haut.iot.operation;import com.haut.iot.book.Book;
import com.haut.iot.book.BookList;import java.util.Scanner;public class AddOperation implements IOperation {@Overridepublic void work(BookList bookList) {System.out.println("新增图书");Scanner scanner = new Scanner(System.in);//扫描器//输入书名System.out.println("Please enter the name of the book :>");String name = scanner.nextLine();//输入作者System.out.println("Please enter author of book :>");String author = scanner.nextLine();//输入价格System.out.println("Please enter the price of the book :>");double price = scanner.nextDouble();//输入类型System.out.println("Please enter the type of book :>");String type = scanner.next(); //这里用next避免nextDouble带来的影响Book book = new Book(name, author, price, type);int curSize = bookList.getUsedSize();//获取当前已存放大小bookList.setBook(curSize, book);bookList.setUsedSize(curSize + 1);//usedSize + 1System.out.println("Added books successfully~");}}

4.2 BorrowOperation：

package com.haut.iot.operation;import com.haut.iot.book.Book;
import com.haut.iot.book.BookList;import java.util.Scanner;public class BorrowOperation implements IOperation {@Overridepublic void work(BookList bookList) {System.out.println("借阅图书");Scanner scanner = new Scanner(System.in);System.out.println("Please enter the name of the book :>");String name = scanner.nextLine();for (int i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);if (book.getBookName().equals(name)) {//可以借阅book.setBorrowed(true);System.out.println("Borrowing successful~");return;}}System.out.println("There is no such book as you want to borrow~");}
}

4.3 DeleteOperation：

package com.haut.iot.operation;import com.haut.iot.book.Book;
import com.haut.iot.book.BookList;import java.util.Scanner;public class DeleteOperation implements IOperation {@Overridepublic void work(BookList bookList) {System.out.println("删除图书");Scanner scanner = new Scanner(System.in);System.out.println("Please enter the name of the book :>");String name = scanner.nextLine();int i = 0;//从0开始遍历for (i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);if (book.getBookName().equals(name)) {//可以删除break;}}if (i == bookList.getUsedSize()) {System.out.println("There are no books you want to delete~");return;}//删除 ==>类比顺序表for (int pos = i; pos < bookList.getUsedSize() - 1; pos++) {Book book = bookList.getBook(pos + 1);bookList.setBook(pos, book); //下一个元素覆盖上一个元素}System.out.println("Delete successful~");bookList.setUsedSize(bookList.getUsedSize() - 1);//有效个数减一}
}

4.4 DisplayOperation：

package com.haut.iot.operation;import com.haut.iot.book.Book;
import com.haut.iot.book.BookList;public class DisplayOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("显示图书");for (int i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);System.out.println(book); //打印每一本书}}
}

4.5 ExitOperation：

package com.haut.iot.operation;import com.haut.iot.book.BookList;public class ExitOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("退出系统");System.exit(1); //退出}
}

4.6 FindOperation：

package com.haut.iot.operation;import com.haut.iot.book.Book;
import com.haut.iot.book.BookList;import java.util.Scanner;public class FindOperation implements IOperation {@Overridepublic void work(BookList bookList) {System.out.println("查找图书");Scanner scanner = new Scanner(System.in);System.out.println("Please enter the name of the book :>");String name = scanner.nextLine();for (int i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);if (book.getBookName().equals(name)) {//可以查找System.out.println(book);System.out.println("Finding successful~");return;}}System.out.println("There is no such book as you are looking for~");}
}

4.7 ReturnOperation：

package com.haut.iot.operation;import com.haut.iot.book.Book;
import com.haut.iot.book.BookList;
import javafx.scene.transform.Scale;import java.util.Scanner;public class ReturnOperation implements IOperation {@Overridepublic void work(BookList bookList) {System.out.println("归还图书");Scanner scanner = new Scanner(System.in);System.out.println("Please enter the name of the book :>");String name = scanner.nextLine();for (int i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);if (book.getBookName().equals(name)) {//可以归还book.setBorrowed(false);System.out.println("Return successful~");return;}}System.out.println("There is no book you want to return~");}
}

5. 测试结果：

测试Admin：

1.查找图书：

2.新增图书：

3.删除图书：

4.显示图书：

测试NormalUser：

1.查找图书：

2.借阅图书：

3.归还图书：

归还后标志位isBorrowed又置为false

0.退出系统：

6. 项目地址：

图书管理系统源代码：
点我跳转到github~