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。
主要包含book对象和book List对象以及Main方法
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")+ "}";
}
}
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;
}
}
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);
}
}
}
主要包含user以及相关对象
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
}
}
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;
}
}
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;
}
}
主要包含各种操作方法
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);
}
添加图书的方法
package operation;
import book.BookList;
import book.Book;
import java.util.Scanner;
public class AddOperation implements IOPeration{
@Override
public 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+1
booklist.setUseSize(currentSize + 1);
System.out.println("添加成功");
}
}
}
寻找图书的方法
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class FindOperation implements IOPeration{
@Override
public 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");
}
}
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 {
@Override
public 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;
}
}
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 {
@Override
public 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;
}
}
借入图书的方法
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class BorrowOperation implements IOPeration{
@Override
public 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;
}
}
归还图书的方法
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class ReturnOperatoin implements IOPeration{
@Override
public 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;
}
}
退出系统所使用的方法。
package operation;
import book.BookList;
public class ExitOperation implements IOPeration{
@Override
public void work(BookList booklist) {
System.out.println("退出系统");
//退出系统指令
System.exit(0);
}
}
这里展示一下管理员界面的部分操作逻辑：
缺点：没有做到持久化存储。以后可以进行升级：将数据存储到数据库或者文件夹中
当前用到的只是数组。后期可以做成网页交互。
好了，图书管理系统就说到这里，大家再见！