简介

哈喽哈喽大家好啊，之前作者也是讲了Java不少的知识点了，为了巩固之前的知识点再为了让我们深入Java面向对象这一基本特性，就让我们完成一个图书管理系统的小项目吧。

项目简介：通过管理员和普通用户的两种操作界面，利用其中的方法以及对象之间的交互，来实现对图书的管理。

源码

book包

主要包含book对象和book List对象以及Main方法

Book类

描述书的有关信息，构造方法和各种getter，setter方法

public class Book {//书的属性：名字，作者，价格，类型，借出情况private String name;private String author;private int price;private String type;private boolean borrowed;public Book(){}public Book(String name, String author, int price, String type) {this.name = name;this.author = author;this.price = price;this.type = type;}/*** 获取* @return name*/public String getName() {return name;}/*** 设置* @param name*/public void setName(String name) {this.name = name;}/*** 获取* @return author*/public String getAuthor() {return author;}/*** 设置* @param author*/public void setAuthor(String author) {this.author = author;}/*** 获取* @return price*/public int getPrice() {return price;}/*** 设置* @param price*/public void setPrice(int price) {this.price = price;}/*** 获取* @return type*/public String getType() {return type;}/*** 设置* @param type*/public void setType(String type) {this.type = type;}/*** 获取* @return borrowed*/public boolean isBorrowed() {return borrowed;}/*** 设置* @param borrowed*/public void setBorrowed(boolean borrowed) {this.borrowed = borrowed;}public String toString() {return "Book{name = " + name + ", author = " + author + ", price = " + price + ", type = " + type + "," +/*", borrowed = " + borrowed*/((isBorrowed() == true) ? " 已被借出" : " 未被借出")+ "}";}
}

BookList

作为书架，利用数组存放书籍.

public class BookList {//定义数组成员表示存放书的数组public Book[] books;//表示书架上存放书的数量private int useSize;//设置最大容量private static final int DEFAULT_CAPACITY = 10;public BookList() {this.books = new Book[DEFAULT_CAPACITY];//先提前放好三本书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", 9, "小说");this.books[2] = new Book("红楼梦", "曹雪芹", 19, "小说");this.useSize = 3;}//书架上书的数量的getter和setter方法public int getUseSize() {return useSize;}public void setUseSize(int useSize) {this.useSize = useSize;}//通过下标获取对应书籍的getter方法public Book getBook(int pos) {return books[pos];}//通过下标和传入的书对象设置对应书籍的setter方法public void setBooks(int pos, Book book) {books[pos] = book;}public Book[] getBooks() {return books;}
}

Main方法

主要的操作逻辑

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 达到发挥的一致性public static User Login() {System.out.println("请输入你的姓名：");Scanner sc = new Scanner(System.in);String name = sc.nextLine();System.out.println("请输入你的身份：1.管理员 2.普通用户 ->");int choice = sc.nextInt();if (choice == 1) {//管理员return new AdminUser(name);} else if (choice == 2) {//普通用户return new NormalUser(name);}return null;}public static void main(String[] args) {BookList booklist = new BookList();//user指向哪个对象 就看返回值User user = Login();while(true) {int choice = user.menu();//System.out.println("choice:" + choice);//根据choice来决定调用哪个方法user.doOperation(choice, booklist);}}
}

user包

主要包含user以及相关对象

父类User

包含基本属性：姓名，menu（菜单）方法的声明，doOperation（执行方法操作）方法的声明。

import book.BookList;
import operation.IOPeration;public abstract class User {protected String name;protected IOPeration[] ioperations;public User(String name) {this.name = name;}public abstract int menu();public void doOperation(int choice, BookList booklist) {ioperations[choice].work(booklist);bao}
}

子类AdminUser

包含管理员使用方法的数组和管理员菜单。

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()};}//管理员专用菜单public int menu() {System.out.println("*************管理员界面*************");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("**********************************");System.out.println("请输入你的操作：");Scanner sc = new Scanner(System.in);int choice = sc.nextInt();return choice;}
}

子类NormalUser

包含普通用户使用方法的数组和普通用户菜单。

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 ReturnOperatoin(),};}//普通用户用菜单public int menu() {System.out.println("*************普通用户界面*************");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 sc = new Scanner(System.in);int choice = sc.nextInt();return choice;}
}

Operation包

主要包含各种操作方法

IOPeration接口

后续使用所有方法继承这个接口，对bookList对象进行相关工作。

package operation;import book.BookList;public interface IOPeration {void work(BookList booklist);
}

AddOperation方法

添加图书的方法

package operation;import book.BookList;
import book.Book;import java.util.Scanner;public class AddOperation implements IOPeration{@Overridepublic void work(BookList booklist) {System.out.println("增加书籍");Scanner sc = new Scanner(System.in);int currentSize = booklist.getUseSize();//用户输入书籍信息System.out.println("请输入书籍的名称：");String name =sc.nextLine();System.out.println("请输入书籍的作者：");String author = sc.nextLine();System.out.println("请输入书籍的类型：");String type = sc.nextLine();//注意：这里将回车放到最后，如果放在前面，下一个nextLine()会读入回车System.out.println("请输入书籍的价格：");int price = sc.nextInt();//创建一个新的book对象导入刚才的信息Book book = new Book(name, author, price, type);//检查书架当中是否有这本书for (int i = 0; i < currentSize; i++) {Book book1 = booklist.getBook(i);//判断书架中的书与新导入书的引用是否相等if(book1 == book) {System.out.println("书架上有这本书，添加失败");return;}}//判断添入书是否超出书架最大容量，未超出则添入书籍if(currentSize == booklist.getBooks().length) {System.out.println("书架已满，添加失败");} else {//在书架中添入书籍booklist.setBooks(currentSize, book);//存放书的数量+1booklist.setUseSize(currentSize + 1);System.out.println("添加成功");}}}

FindOperation方法

寻找图书的方法

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class FindOperation implements IOPeration{@Overridepublic void work(BookList booklist) {System.out.println("寻找书籍");Scanner sc = new Scanner(System.in);System.out.println("请输入您要寻找的书籍");String name = sc.nextLine();int currentSize = booklist.getUseSize();for (int i = 0; i < currentSize; i++) {Book book = booklist.getBook(i);if(book.getName().equals(name)) {System.out.println("找到了，是这本书：");System.out.println(book);return;}}System.out.println("没有找到这本书");}
}

DelOperation方法

删除图书所使用的方法

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class DelOperation implements IOPeration {@Overridepublic void work(BookList bookList) {System.out.println("删除书籍");//1.找到有没有这本书System.out.println("请输入要删除书的名字");Scanner sc = new Scanner(System.in);String name = sc.nextLine();int currentSize = bookList.getUseSize();for (int i = 0; i < currentSize; i++) {Book book = bookList.getBook(i);if (book.getName().equals(name)) {//2.如果有，从这本书后面开始，从前往后向前覆盖for (; i < currentSize; i++) {Book book1 = bookList.getBook(i + 1);bookList.setBooks(i, book1);}//3.将最后一本书置为空bookList.setBooks(currentSize - 1, null);//数组最大容量减少bookList.setUseSize(currentSize - 1);System.out.println("删除成功！");return;}}//未删除成功的情况System.out.println("该书不存在，删除失败");return;}
}

ShowOperation方法

显示所有图书的方法

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class DelOperation implements IOPeration {@Overridepublic void work(BookList bookList) {System.out.println("删除书籍");//1.找到有没有这本书System.out.println("请输入要删除书的名字");Scanner sc = new Scanner(System.in);String name = sc.nextLine();int currentSize = bookList.getUseSize();for (int i = 0; i < currentSize; i++) {Book book = bookList.getBook(i);if (book.getName().equals(name)) {//2.如果有，从这本书后面开始，从前往后向前覆盖for (; i < currentSize; i++) {Book book1 = bookList.getBook(i + 1);bookList.setBooks(i, book1);}//3.将最后一本书置为空bookList.setBooks(currentSize - 1, null);//数组最大容量减少bookList.setUseSize(currentSize - 1);System.out.println("删除成功！");return;}}//未删除成功的情况System.out.println("该书不存在，删除失败");return;}
}

BorrowOperation方法

借入图书的方法

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class BorrowOperation implements IOPeration{@Overridepublic void work(BookList booklist) {System.out.println("借出书籍");/** 1.你要借阅什么书* 2.你要借阅的书存不存在* 3.如何完成借阅过程 isBorrowed->true 已借出 isBorrowed->false 未借出* */System.out.println("请输入你要借阅的图书名字");Scanner sc = new Scanner(System.in);String name = sc.nextLine();int currentSize = booklist.getUseSize();for (int i = 0; i < currentSize; i++) {Book book = booklist.getBook(i);//该图书存在的情况if(book.getName().equals(name) && book.isBorrowed() == false) {book.setBorrowed(true);System.out.println("借出成功");System.out.println(book);return;}}//未被借出的情况System.out.println("该图书已被借出或者不存在，借阅失败");return;}
}

ReturnOperation方法

归还图书的方法

package operation;import book.Book;
import book.BookList;import java.util.Scanner;public class ReturnOperatoin implements IOPeration{@Overridepublic void work(BookList booklist) {System.out.println("归还书籍");System.out.println("请输入你要归还的图书");Scanner sc = new Scanner(System.in);String name = sc.nextLine();int currentSize = booklist.getUseSize();for (int i = 0; i < currentSize; i++) {Book book = booklist.getBook(i);//该图书存在的情况if(book.getName().equals(name) && book.isBorrowed() == true) {book.setBorrowed(false);System.out.println("归还成功");System.out.println(book);return;}}//未被借出的情况System.out.println("该图书已被归还或者不存在，归还失败");return;}
}

ExitOperation方法

退出系统所使用的方法。

package operation;import book.BookList;public class ExitOperation implements IOPeration{@Overridepublic void work(BookList booklist) {System.out.println("退出系统");//退出系统指令System.exit(0);}
}