前言
这篇博客是在学习了一部分Java基础语法之后的练习项目，通过这个小项目的练习，对Java中的类和对象，抽象类和接口，面向对象的继承、多态和封装、组合等进行熟悉理解；抽象出不同的对象，将对象进行合理的设计，完成对象之间的交互，面向对象进行编程。
1. 项目需求
图书管理系统，面向管理员和普通用户使用，对管理员的开放的功能有：添加图书，删除图书，查找图书，显示图书和退出程序等；对普通用户的开放的功能有：查找图书，借阅图书，归还图书和退出程序。
2. 实现思路
先抽象提取出不同的对象，首先想到的对象是用户和书，
用户可分为管理员和普通用户，将管理员和普通用户共有的属性设置为一个父类User，管理员和普通用户继承User，可以先将父类设置为普通类，在写码过程如果合适可以修改为抽象类；
系统对书进行管理，书本身就可以抽象为一个对象；对多本书进行操作管理，书架也可以抽象为一个对象；所以书和书架用两个类来实现，书架可以设计为一个数组；
这里系统对书进行管理，其实就是对书架对应数组进行操作，不同的操作可以通过一个标准去实现，也就是可以定义一个接口，每一个操作类去实现这个接口，完成向上转型，通过接口实现多态；
然后写代码的过程中思考完善各个对象的成员，最终实例化对象，通过不同对象之间的交互完成管理系统。
3. 代码实现
包的设计
book包
Book类
package book;
public class Book {
private String name;//书名
private String author;//书的作者
private int price;//书的价格
private String type;//书的类型
private boolean borrowed;//是否被借出，默认false
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() {
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 getBorrowed() {
return borrowed;
}
public void setBorrowed(Boolean borrowed) {
this.borrowed = borrowed;
}
@Override
public String toString() {
return "Book{" +
"name='" + name + '\'' +
", author='" + author + '\'' +
", price=" + price +
", type='" + type + '\'' +
", borrowed=" + ((borrowed==true) ? "已借出" : "未借出") +
'}';
}
}
BookList类
package book;
public class BookList {
private Book[] books = new Book[100];
private int usedsize;
//书架当中默认有三本书
public BookList() {
this.books[0] = new Book("三国演义","罗贯中",66,"小说");
this.books[1] = new Book("西游记","吴承恩",68,"小说");
this.books[2] = new Book("红楼梦","曹雪芹",64,"小说");
this.usedsize = 3;
}
public int getUsedsize() {
return usedsize;
}
public void setUsedsize(int usedsize) {
this.usedsize = usedsize;
}
public Book getBooks(int pos){
return this.books[pos];
}
public void setBooks(Book book, int pos) {
this.books[pos] = book;
}
}
operations包
IOperation接口
package operations;
import book.BookList;
public interface IOperation {
void work(BookList bookList);
}
AddOperation类
package operations;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class AddOperation implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("新增图书");
//输入图书信息
System.out.println("输入新增图书名称:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
System.out.println("输入新增图书作者:");
String author = scanner.nextLine();
System.out.println("输入新增图书价格:");
int price = scanner.nextInt();
scanner.nextLine();
System.out.println("输入新增图书类型:");
String type = scanner.nextLine();
Book book = new Book(name, author, price, type);
//获取存书位置
int currentSize = bookList.getUsedsize();
//把书放到书架（数组）
bookList.setBooks(book, currentSize);
//书的总数加1
bookList.setUsedsize(currentSize+1);
System.out.println("添加成功！");
}
}
BorrowOperation类
package operations;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class BorrowOperation implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("借阅图书");
System.out.println("输入要借阅图书的名称:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
int currentSize = bookList.getUsedsize();
for (int i = 0; i < currentSize; i++) {
Book book = bookList.getBooks(i);
if (name.equals(book.getName())){
if(book.getBorrowed()){
System.out.println("该书已经被借出！");
return;
}else {
book.setBorrowed(true);
System.out.println("借阅成功！");
return;
}
}
}
System.out.println("没有找到你要借阅的书");
}
}
DelOperation类
package operations;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class DelOperation implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("删除图书");
System.out.println("输入要删除图书的名称:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
int currentSize = bookList.getUsedsize();
//找到并记录要删除书的下标
int index = -1;
for (int i = 0; i < currentSize; i++) {
Book book = bookList.getBooks(i);
if (name.equals(book.getName())){
index = i;
break;
}
}
if(-1 == index) {
System.out.println("没有找到要删除的这本书！");
}else {
for (int i = index; i < currentSize-1; i++) {
Book book = bookList.getBooks(i+1);
bookList.setBooks(book, i);
}
//每次删除，都要将原来最后一本书位置的引用置空
bookList.setBooks(null,currentSize-1);
bookList.setUsedsize(currentSize-1);
System.out.println("删除成功");
}
}
}
DisplayOperation类
package operations;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class DisplayOperation implements IOperation{
@Override
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.getBooks(i);
System.out.println(book);
}
}
}
ExitOperation类
package operations;
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类
import book.Book;
import book.BookList;
import java.util.Scanner;
public class FindOperation implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("查找图书");
System.out.println("输入要查找图书的名称:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
int currentSize = bookList.getUsedsize();
for (int i = 0; i < currentSize; i++) {
Book book = bookList.getBooks(i);
if (name.equals(book.getName())){
System.out.println("找到了，该书信息如下:");
System.out.println(book);
return;
}
}
System.out.println("没有找到这本书！");
}
}
ReturnOperation类
package operations;
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");
System.out.println("输入要归还图书的名称:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
int currentSize = bookList.getUsedsize();
for (int i = 0; i < currentSize; i++) {
Book book = bookList.getBooks(i);
if (name.equals(book.getName())){
if(book.getBorrowed()){
book.setBorrowed(false);
System.out.println("归还成功！");
return;
}else {
System.out.println("该书未借出！");
return;
}
}
}
System.out.println("没有找到你要归还的书");
}
}
user包
User类
public abstract class User {
protected String name;
protected IOperation[] iOperation;
public User(String name) {
this.name = name;
}
public abstract int menu();
public void doOperation(int choice, BookList bookList){
iOperation[choice].work(bookList);
}
}
AdminUser类
package user;
import operations.*;
import java.util.Scanner;
public class AdminUser extends User{
public AdminUser(String name) {
super(name);
this.iOperation = new IOperation[]{
new ExitOperation(),
new FindOperation(),
new AddOperation(),
new DelOperation(),
new DisplayOperation()
};
}
@Override
public int menu() {
System.out.println("---------------------------------");
System.out.println("Hello 管理员:>"+""+name+" 欢迎来到图书管理系统！");
System.out.println(" 1.查找图书 2.新增图书");
System.out.println(" 3.删除图书 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 scanner = new Scanner(System.in);
int choice = scanner.nextInt();
return choice;
}
}
NormalUser类
package user;
import operations.*;
import java.util.Scanner;
public class NormalUser extends User{
public NormalUser(String name) {
super(name);
this.iOperation = new IOperation[]{
new ExitOperation(),
new FindOperation(),
new BorrowOperation(),
new ReturnOperation()
};
}
@Override
public int menu() {
System.out.println("---------------------------------");
System.out.println("Hello 用户:>"+name+" 欢迎来到图书管理系统！");
System.out.println(" 1.查找图书 2.借阅图书");
System.out.println(" 3.归还图书 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类
import book.BookList;
import user.AdminUser;
import user.NormalUser;
import user.User;
import java.util.Scanner;
public class Main {
public static User login(){
System.out.println("请输入你的姓名:");
Scanner scanner = new Scanner(System.in);
String userName = scanner.nextLine();
System.out.println("请确认你的身份:> |1->管理员|0->普通用户|");
int choice = scanner.nextInt();
if(1==choice){
return new AdminUser(userName);
}else{
return new NormalUser(userName);
}
}
public static void main(String[] args) {
//准备数据
BookList bookList = new BookList();
//登录
User user = login();
while (true) {
int choice = user.menu();
user.doOperation(choice, bookList);
}
}
}
4. 实现效果
管理员
普通用户
以上就是JavaSE实现图书管理系统的示例代码的详细内容，更多关于JavaSE图书管理系统的资料请关注脚本之家其它相关文章！