简介

通过登录确认自己的身份，如果是管理员，对图书进行增，删，查，显示等，如果是学生，则实现借阅，归还，查找等功能。

知识点

类

链接: link.

封装

链接: link.

包

链接: link.

继承

链接: link.

接口

链接: link.

多态

链接:link.

创建书（Book）

package book;public class Book {/*一本书的属性包括书名，作者，价格，类型，编号，以及状态*/private String name;private String author;private int price;private String type;private int num;private boolean status;//提供构造方法public Book(String name, String author, int price, String type, int num) {this.name = name;this.author = author;this.price = price;this.type = type;this.num = num;}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 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 int getNum() {return num;}public void setNum(int num) {this.num = num;}public boolean isStatus() {return status;}public void setStatus(boolean status) {this.status = status;}//toString 方法打印@Overridepublic String toString() {return "Book{" +"name='" + name + '\'' +", author='" + author + '\'' +", price=" + price +", type='" + type + '\'' +", num=" + num +((status == true) ? " 已借出 " : " 未借出 ") +'}';}
}

书架（BookList）

这里提前往书架放了三本书

package book;public class BookList {//书都是同一类型的元素，创建一个Book类型的数组private Book[] books;private int size;//先给书架放三本书public BookList() {this.books = new Book[10];books[0] = new Book("张","小张",10,"小说",1);books[1] = new Book("王","小王",23,"小说",3);books[2] = new Book("李","小李",20,"小说",2);this.size = 3;}public int getSize() {return size;}public void setSize(int size) {this.size = size;}public void setBooks(int pos, Book book) {this.books[pos] = book;}public Book getBook(int pos) {return this.books[pos];}
}

主函数（Main）

import book.BookList;
import user.Administrator;
import user.Ordinary;
import user.User;import java.util.Scanner;public class Main {public static User login() {Scanner sc = new Scanner(System.in);System.out.println("请输入姓名：");String name = sc.next();System.out.println("请确认您的身份：1 > 管理员  0 > 学生");int choice = sc.nextInt();if(choice == 1){return new Administrator(name);}else{return new Ordinary(name);}}public static void main(String[] args) {BookList bl = new BookList();//登录User user = login();//选择菜单while(true){int choice = user.menu();user.doOperation(choice,bl);}}
}

用户（User）

package user;import book.BookList;
import operation.IOperation;
//抽象类，主要为了被继承
public abstract class User {public String name;public IOperation[] operation;public User(String name) {this.name = name;}public abstract int menu();public void doOperation(int choice, BookList bl) {this.operation[choice].work(bl);}
}

管理员（Administrator）

package user;import operation.*;import java.util.Scanner;public class Administrator extends User{public Administrator(String name) {super(name);this.operation = new IOperation[]{new ExiOperation(),new FinOperation(),new AddOperation(),new DelOperation(),new DisOperation()};}@Overridepublic int menu() {System.out.println("欢迎" + this.name + "进入图书管理系统！");Scanner sc = new Scanner(System.in);System.out.println("=============");System.out.println("1.查找图书");System.out.println("2.增加图书");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("=============");int choice = sc.nextInt();return choice;}
}

接口（IOperation）

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

查(FinOperation)

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class FinOperation implements IOperation{@Overridepublic void work(BookList bl) {System.out.println("查找书籍");Scanner sc = new Scanner(System.in);System.out.println("请输入要查找的书籍名字：");String name = sc.next();for (int i = 0; i < bl.getSize(); i++) {Book book = bl.getBook(i);if(book.getName().equals(name)){System.out.println("有此书籍！");System.out.println(book);return;}}System.out.println("未找的您需要的书籍！");}
}

增(AddOperation)

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class AddOperation implements IOperation {@Overridepublic void work(BookList bl) {Scanner sc = new Scanner(System.in);System.out.println("添加图书");System.out.println("请输入图书的名字：");String name = sc.nextLine();System.out.println("请输入图书的作者：");String author = sc.nextLine();System.out.println("请输入图书价格：");int price = sc.nextInt();System.out.println("请输入图书的类型：");String type = sc.next();System.out.println("请输入图书的编号：");int num = sc.nextInt();Book book = new Book(name,author,price,type,num);int curSize = bl.getSize();//拿到长度bl.setBooks(curSize,book);bl.setSize(curSize+1);System.out.println("添加成功！");}
}

删(DelOperation)

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class DelOperation implements IOperation{@Overridepublic void work(BookList bl) {System.out.println("删除图书");System.out.println("请输入需要删除的书籍名字：");Scanner sc = new Scanner(System.in);String name = sc.nextLine();int i = 0;for (; i < bl.getSize(); i++) {Book book = bl.getBook(i);if(book.getName().equals(name)){break;}}if(i >= bl.getSize()){System.out.println("没有找到此书籍");return;}int j = i;for(; j < bl.getSize() - 1; j++){Book book = bl.getBook(j + 1);bl.setBooks(j,book);}int cueSize = bl.getSize();bl.setSize(cueSize-1);System.out.println("成功删除此书籍！");}
}

显示(DisOperation)

package operation;import book.Book;
import book.BookList;public class DisOperation implements IOperation{@Overridepublic void work(BookList bl) {System.out.println("显示图书");for (int i = 0; i < bl.getSize(); i++) {Book book = bl.getBook(i);System.out.println(book);}}
}

退出(ExiOperation)

package operation;import book.BookList;public class ExiOperation implements IOperation{@Overridepublic void work(BookList bl) {System.out.println("退出系统");System.exit(1);}
}

学生(Ordinary)

package user;import operation.*;import java.util.Scanner;public class Ordinary extends User {public Ordinary(String name) {super(name);this.operation = new IOperation[]{new ExiOperation(),new FinOperation(),new BorrOperation(),new RetOperation(),new DisOperation()};}@Overridepublic int menu() {System.out.println("欢迎" + this.name + "同学进入图书管理系统！");Scanner sc = new Scanner(System.in);System.out.println("==============");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("4.显示图书");System.out.println("0.退出系统");System.out.println("==============");int choice = sc.nextInt();return choice;}
}

查(FinOperation)

同管理员

借(BorrOperation)

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class BorrOperation implements IOperation{@Overridepublic void work(BookList bl) {System.out.println("借阅书籍");System.out.println("请输入需要借阅的书籍名字：");Scanner sc = new Scanner(System.in);String name = sc.nextLine();for (int i = 0; i < bl.getSize(); i++) {Book book = bl.getBook(i);if(book.getName().equals(name)) {System.out.println("请取走您要的书籍！");book.setStatus(true);System.out.println(book);return;}}System.out.println("没有你需要的书籍！");}
}

归(RetOperation)

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class RetOperation implements IOperation{@Overridepublic void work(BookList bl) {System.out.println("归还图书");Scanner sc = new Scanner(System.in);System.out.println("请输入您要归还的书籍名字！");String name = sc.nextLine();for (int i = 0; i < bl.getSize(); i++) {Book book = bl.getBook(i);if(book.getName().equals(name)) {book.setStatus(false);System.out.println(book);return;}}}
}

显示(DisOperation)

同管理员

退出(ExiOperation)

同管理员

管理员运行截图

学生运行结果