Java实现图书管理系统-阿里云开发者社区

1.系统导读

Java最主要的特征便是面向对象，这个小练习就是让我们加强对面向对象的理解，所以系统的实现肯定是通过分多个包和类来共同实现系统功能的。

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该系统的通过四部分来实现：

1.book包下为图书信息的存储

2.user包下为用户的信息及操作逻辑

3.Main文件下为整个系统的逻辑实现

4.operation包下为系统功能的具体实现

首先是登陆页面，输入姓名后选择身份，然后跳转到不同的菜单（管理员和普通用户两份菜单），然后在用户进一步选择功能以后去实现对应的功能。

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2.创建系统所需类

2.1图书信息（book包）

该系统是通过顺序表来实现的，在顺序表的数组中存储的是每一本书的信息，然后通过顺序表进行增删查改功能的实现（顺序表了解可以博主之前的文章【Java数据结构之顺序表】

Book.java

书需要包含书名、作者、价格、类型、是否被借出等信息

package book;
public class Book {
    private String name;
    private String author;
    private int price;
    private String type;
    private boolean isBorrowed;
    public Book(String name, String author, int price, String type) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.type = type;
    }
    public String getName() {//以下getter、setter实现通过idea中的快捷键alt+insert来实现
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAuthor() {
        return author;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
    public int getPrice() {
        return price;
    }
    public void setPrice(int 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;
    }
    @Override
    //重写toString()方法是为了打印书的具体信息，如果不重写不会打印出书的具体内容
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                 ((isBorrowed==true)?"已被借出":"未被借出") +
                '}';
    }
}

BookList.java

package book;
public class BookList {
    private Book [] books=new Book[10];
    //顺序表数组，暂时先将长度设小，随着接下来的学习，该部分还会继续改进
    private int useSize;
    //记录目前书的本数
    public BookList() {
    //在构造方法中先存储三本书的信息
        books[0] = new Book("三国演义","罗贯中",17,"小说");
        books[1] = new Book("西游记","吴承恩",47,"小说");
        books[2] = new Book("水浒传","施耐庵",37,"小说");
        this.useSize=3;
    }
    public int getUseSize() {
        return useSize;
    }
    public void setUseSize(int useSize) {
        this.useSize = useSize;
    }
    //以下两个方法为手敲（非快捷键）
    public Book getPos(int pos) {
        return this.books[pos];
    }//得到角标为pos位置的书
    public void setBook(int pos,Book book) {
        this.books[pos] = book;
    }//将角标为pos位置的书改为函数传参传过来的book.
}

2.2用户信息（user包）

因为使用者有管理者和普通用户两个对象，但两者多有相同属性且有细致区别的方法，所以将相同代码抽取出来创建抽象类User，再建立AdminUser和NormalUser分别继承User。

User.java

package user;
import book.BookList;
import operation.IOperation;
public abstract class User {
    String name;//使用者姓名
    IOperation[] iOperations;
    //创建使用者操作数组，数组内用于存储多项功能
    public User(String name) {
        this.name = name;
    }
    public abstract int menu();
    //两个对象的菜单不同，所以创建抽象方法
    public void doWork(int choice, BookList bookList) {
        iOperations[choice].work(bookList);
    }//这个方法是在用户进行选择后，根据对应操作数组的选择进行不同操作
}

AdminUser.java

package user;
import operation.*;
import java.util.Scanner;
public class AdminUser extends User {
    public AdminUser(String name) {
        super(name);
        this.iOperations = new IOperation[] {
                new ExitOperation(),
                new FindOperation(),
                new AddOperation(),
                new DelOperation(),
                new DisplayOperation()
        };
        //构造方法内实例化不同对象对应的不同操作菜单
    }
    //打印不同菜单
    public int menu() {
        System.out.println("===========管理员菜单===========");
        System.out.println("hello " + this.name +" 欢迎来到这里！");
        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;
        //用户进行选择，选择后将choice值返回，调用实现对应功能
    }
}

NormalUser.java

package user;
import operation.*;
import java.util.Scanner;
public class NormalUser extends User {
    public NormalUser(String name) {
        super(name);
        this.iOperations = new IOperation[] {
                new ExitOperation(),
                new FindOperation(),
                new BorrowOperation(),
                new ReturnOperation(),
        };
    }
    public int menu() {
        System.out.println("===========普通用户的菜单===========");
        System.out.println("hello " + this.name +" 欢迎来到这里！");
        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;
    }
}

3.系统逻辑（Main.java）

import book.BookList;
import user.AdminUser;
import user.NormalUser;
import user.User;
import java.util.Scanner;
public class Main {
//无论对象是谁，都需要先展示登录界面
    public static User login() {
        System.out.println("请输入你的姓名：");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        System.out.println("请输入你的身份：1-》管理员,0-》普通用户");
        int choice = scanner.nextInt();
        if(choice == 1) {
        //根据choice的不同值，实例化不同对象并将其返回
            return new AdminUser(name);
        }else {
            return new NormalUser(name);
        }
    }
    public static void main(String[] args) {
        BookList bookList=new BookList();
        User user=login();
        while (true) {
            int choice = user.menu();//发生了动态绑定  -》 多态
            //根据你的choice 调用合适的操作
            user.doWork(choice, bookList);
        }
    }
}

4.功能实现（operation包）

因为系统有多项功能，所以在这个包下，将每一个功能都独立创建为一个类来具体清晰实现，为了这些类中的代码复用，又抽象出来一个接口（多个类共有的功能）

Ioperation.java
package operation;
import book.BookList;
import java.util.Scanner;
public interface IOperation {
    Scanner scanner = new Scanner(System.in);
    void work(BookList bookList);
}

AddOperation.java

新增图书需要new图书并将信息初始化，然后将其放在顺序表最后位置

package operation;
import book.Book;
import book.BookList;
public class AddOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("新增图书！");
        System.out.println("请输入书名：");
        String name = scanner.next();
        System.out.println("请输入作者：");
        String author= scanner.next();
        System.out.println("请输入类型:");
        String type=scanner.next();
        System.out.println("请输入价格：");
        int price=scanner.nextInt();
        Book book=new Book(name, author,price,type);
        //实例化新增图书
        int size= bookList.getUseSize();
        //导包后调用bookList.getUseSize();函数确定新增图书存放位置
        bookList.setBook(size,book);
        //新增图书
        bookList.setUseSize(size+1);
        //有效书目加一
        System.out.println("新增图书成功！");
    }
}

BorrowOperation.java

输入借阅图书书名后遍历数组查找，找到后将图书借阅情况更改

package operation;
import book.Book;
import book.BookList;
public class BorrowOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("借阅图书！");
        System.out.println("请输入要借阅图书的名字");
        String name=scanner.nextLine();
        int size=bookList.getUseSize();
        for (int i = 0; i < size; i++) {
            Book book=bookList.getPos(i);
            if (name.equals(book.getName())) {
                book.setBorrowed(true);
                System.out.println("借阅成功");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有你要借阅的书");
    }
}

DelOperation.java
package operation;
import book.Book;
import book.BookList;
public class DelOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("删除图书！");
        System.out.println("请输入要删除的图书");
        String name=scanner.next();
        int size= bookList.getUseSize();
        //设置循环先进行书目查找
        for (int i = 0; i < size; i++) {
            Book book=bookList.getPos(i);
            //找到后数组前移覆盖此书
            if (name.equals(book.getName())) {
                for (int j = i; j < size-1; j++) {
                    Book bookNext=bookList.getPos(j+1);
                    bookList.setBook(j,bookNext);
                }
                bookList.setBook(size,null);
                bookList.setUseSize(size-1);
                //删除书目后有效书目-1；
                System.out.println("删除完成");
                return;
            }
        }
        System.out.println("该书不存在");
    }
}

DisplayOperation.java

把已有书目信息全部打印

package operation;
import book.Book;
import book.BookList;
import java.util.Arrays;
public class DisplayOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("浏览图书！");
        int size= bookList.getUseSize();
        for (int i = 0; i < size; i++) {
            Book book=bookList.getPos(i);
            System.out.println(book);
        }
    }
}

ExitOperation.java

退出系统

package operation;
import book.BookList;
public class ExitOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("退出系统！");
        System.exit(0);
    }
}

FindOperation.java

package operation;
import book.Book;
import book.BookList;
public class FindOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("查找图书！");
        System.out.println("请输入要查找的图书：");
        String name=scanner.next();
        int size= bookList.getUseSize();
        for (int i = 0; i < size; i++) {
            Book book = bookList.getPos(i);
            if (name.equals(book.getName())) {
                System.out.println("找到了这本书，书的信息如下：");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没找到");
    }
}

ReturnOperation.java

package operation;
import book.Book;
import book.BookList;
public class ReturnOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("归还图书！");
        System.out.println("请输入要归还图书的名字");
        String name=scanner.nextLine();
        int size=bookList.getUseSize();
        for (int i = 0; i < size; i++) {
            Book book=bookList.getPos(i);
            if (name.equals(book.getName())) {
                book.setBorrowed(true);
                System.out.println("归还成功");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有你要归还的书");
    }
}

Java实现图书管理系统