Java之图书管理系统

思路：

1.最终程序在Main上运行

2.书

3.操作

4.用户

book

Book

package book;

public class Book {
    private String name;//书名
    private String author;//作者
    private String price;//价格
    private String type;//类型
    private boolean isBorrowed;//是否被借出 默认是false

    public Book(String name, String author, String price, String type) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.type = type;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String 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
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price='" + price + '\'' +
                ", type='" + type + '\'' +
               /* ", isBorrowed=" + isBorrowed */((isBorrowed == true)?"已经被借出":"未被借出")+
                '}';
    }
}

BookList

package book;

/*书架
*
*
* */
public class BookList {

    private Book[] books = new Book[10];
    private int usedSize;//计数器 来记录 当前实际放的书的数目

    public BookList(){
        //构造方法  来初始化成员    当实例化BookList这个对象的时候，就能有三本书
        this.books[0] = new Book("三国演义","罗贯中","10","小说");
        this.books[1] = new Book("西游记","吴承恩","23","小说");
        this.books[2] = new Book("红楼梦","曹雪芹","8","小说");
        this.usedSize = 3;
    }

    public Book getBook(int pos){
        return books[pos];//返回pos位置的书
    }

    public void setBooks(int pos,Book book){
        books[pos] = book;//在pos位置放一本书
    }

    public int getUsedSize() {
        return usedSize;
    }

    public void setUsedSize(int usedSize) {
        this.usedSize = usedSize;
    }
}

operation

IOPeration

package operation;

import book.BookList;

public interface IOPeration {
    void work(BookList bookList);//标准制定
}

AddOperation

package operation;
import book.Book;
import book.BookList;

import java.util.Scanner;

public class AddOperation implements IOPeration{
    public void work(BookList bookList){
        System.out.println("新增图书！");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入书名：");
        String name = scanner.nextLine();
        System.out.println("请输入作者：");
        String author = scanner.nextLine();
        System.out.println("请输入价格：");
        String price = scanner.nextLine();
        scanner.nextLine();//多读一次（整型在上面，字符串在下面，会把回车都进去）
        System.out.println("请输入类型：");
        String type = scanner.nextLine();

        Book book = new Book(name,author,price,type);
        int currentSize = bookList.getUsedSize();//!!!!!

        //如果有这本书 就不能添加了
        for(int i = 0;i < currentSize;i++){
            Book book1 = bookList.getBook(i);
            if(book1.getName().equals(name)){
                System.out.println("书架存在这种书，不能进行添加！");
                return;

            }
        }
        //默认放到了数组的最后的位置
        bookList.setBooks(currentSize,book);
        //让usedSize++
        bookList.setUsedSize(currentSize+1);

    }
}

BorrowedOperation

package operation;

import book.Book;
import book.BookList;

import java.util.Scanner;

public class BorrowedOperation implements IOPeration {
    @Override
    public void work(BookList bookList) {
        System.out.println("借阅图书！");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入书名：");
        String name = scanner.nextLine();

        int currentSize = bookList.getUsedSize();//!!!!!

        for(int i = 0;i < currentSize;i++){
            Book book1 = bookList.getBook(i);
            if(book1.getName().equals(name)){
                if(book1.isBorrowed()==false){
                    book1.setBorrowed(true);
                    System.out.println("借阅成功");
                }else{
                    System.out.println("这本书已经被借走了");
                }

                return;

            }
        }
        System.out.println("没有你要借阅的图书！");
    }
}

DelOperation

package operation;
import java.util.Scanner;
import book.BookList;
import book.Book;
public class DelOperation implements IOPeration {
    @Override
    public void work(BookList bookList) {
        System.out.println("删除图书！");
        //1.找到你要删除的书
        int currentSize = bookList.getUsedSize();
        if(currentSize == 0){
            System.out.println("书架为空，不能删除!");
            return;
        }

        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入书名：");
        String name = scanner.nextLine();

        int index = -1;
        for(int i = 0;i<currentSize;i++){
            Book book1 = bookList.getBook(i);
            if(book1.getName().equals(name)){
                index = i;
                break;
            }
        }
        //2.index != -1  有这本书 开始删除
        if(index == -1){
            System.out.println("没有你要删除的书！");
            return;
        }
        for(int i = index;i<currentSize -1;i++){
            Book book1 = bookList.getBook(i+1);
            bookList.setBooks(i,book1);
        }
        //当书被删掉之后，需要维持usedSize
        bookList.setUsedSize(currentSize-1);

    }
}

ExitOperation

package operation;

import book.BookList;

public class ExitOperation implements IOPeration {
    @Override
    public void work(BookList bookList) {
        System.out.println("退出系统");
        int currentSize = 0;
        for(int i = 0; i < currentSize; i++){
            bookList.setBooks(i,null);
        }

        bookList.setUsedSize(0);
        System.exit(0);
    }
}

FindOperation 

package operation;

import book.Book;
import book.BookList;
import java.util.Scanner;
public class FindOperation implements IOPeration {
    public void work(BookList bookList){
        System.out.println("查找图书！");

        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入你要查找的图书：");
        String name = scanner.nextLine();

        int currentSize = bookList.getUsedSize();
        for(int i = 0;i < currentSize;i++){
            Book book = bookList.getBook(i);
            if(book.getName().equals(name)){
                System.out.println("找到了你查找的书：");
                System.out.println(book);
                return;
            }

        }

        System.out.println("不好意思，你好像没有这笔书！");

    }
}

ReturnOperation

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("归还图书!");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入书名：");
        String name = scanner.nextLine();

        int currentSize = bookList.getUsedSize();//!!!!!

        for(int i = 0;i < currentSize;i++){
            Book book1 = bookList.getBook(i);
            if(book1.getName().equals(name)){
                book1.setBorrowed(false);
                System.out.println("归还成功");
                return;
            }
        }
        System.out.println("没有你要归还的图书！");
    }
    }

ShowOperation

package operation;

import book.Book;
import book.BookList;

public class ShowOperation implements IOPeration{
    public void work(BookList bookList) {
        System.out.println("显示图书");

        int currentSize = bookList.getUsedSize();
        for(int i = 0;i < currentSize;i++){
            Book book = bookList.getBook(i);
            System.out.println(book);
        }

        }

    }

 user

User

package user;

import book.BookList;
import operation.IOPeration;

public abstract class User {
    protected String name;

    public IOPeration[] ioPerations;//只是定义并没有初始化大小
    public User(String name) {
        this.name = name;
    }

    public abstract int menu();

    public void doOperation(int choice, BookList bookList ){
        ioPerations[choice].work(bookList);

    }
}

AdminUser

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 ShowOperation()
        };
    }
    public int menu(){
        System.out.println("*********************");
        System.out.println("hello"+this.name+"欢迎来到管理员菜单！");
        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;
    }
}

NormalUser

package user;

import operation.*;

import java.util.Scanner;

/*普通用户*/
public class NormalUser extends User{
    public NormalUser(String name) {
        super(name);
        this.ioPerations = new IOPeration[]{
                new ExitOperation(),
                new FindOperation(),
                new BorrowedOperation(),
                new ReturnOperation(),
        };
    }


    public int menu(){
        System.out.println("*********************");
        System.out.println("hello "+this.name+"欢迎来到普通用户菜单！");
        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("**********************");
        System.out.println("请输入你的操作：");
        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();
        return choice;
    }
}

Main 

import book.BookList;
import user.AdminUser;
import user.NormalUser;
import user.User;
import java.util.Scanner;
public class Main{
    //可以利用返回值的向上转型 达到返回的一致性
    public static User login(){
        //登陆系统
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入你的姓名：");
        String name = scanner.nextLine();
        System.out.println("请输入你的身份：1-》管理员 0-》普通用户");
        int ret = scanner.nextInt();
        if(ret == 1){
            /*AdminUser adminUser = new AdminUser(name);
            return adminUser;*/
            return new AdminUser(name);
        }else{
            /*NormalUser normalUaer = new NormalUser(name);
            return normalUaer;*/
            return new NormalUser(name);
        }

    }

    public static void main(String[] args){
        BookList bookList = new BookList();//实例化书架这个对象，默认有三本书
        User user = login();//向上转型   有可能是管理员/普通用户
        while(true){
            int choice = user.menu();
            //user是哪个对象？choice是几--》能够确定：我能够操作哪个对象的哪个方法
            //通过这两个变量 可以确定了 但是怎么联系起来？
            /*
             *1.先让双方存好对应自己的操作
             *2.就是调用对应的操作！
             **/
            user.doOperation(choice, bookList);//获得对应用户的对用操作
        }
    }
}

 运行结果（一种）