文章目录
- 前言
- 一、实现的功能
- 二、具体的代码
- book包(书的信息和书架)
- operation包(实现具体的功能)
- user包(管理员 用户 main方法)
- 总结
前言
本篇文章我们来学习一个综合案例——图书管理系统,是对继承,封装和多态的一个小练习,通过这个案例可以加深我们对语法的理解。
一、实现的功能
实现对图书的管理,我们登录时有两个身份,一个是图书管理员,一个是普通用户,这两个实现的功能各不一样。
二、具体的代码
有三个包和一个main函数。
book包(书的信息和书架)
book包:
book类:
package book;
public class book {
private String name; //书名
private String author;//作者
private int price;//价格
private String type;//类型如小说散文等
private boolean isBorrowed;//是否被借出
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 isBorrowed() {
return isBorrowed;
}
public void setBorrowed(boolean borrowed) {
isBorrowed = borrowed;
}
public book(String name, String author, int price, String type) {
this.name = name;
this.author = author;
this.price = price;
this.type = type;
}
@Override
public String toString() {
return "book{" +
"name='" + name + '\'' +
", author='" + author + '\'' +
", price=" + price +
", type='" + type + '\'' +
((isBorrowed==true)?"已经借出":"未借出")+'}';
}
}
booklist类:
package book;
public class booklist {
private book[]books=new book[10]; //最多可以放十本书
private int usedSize;//实时记录,当前books这个数组中有多少本书。
public booklist(){
books[0]=new book("三国演义","罗贯中",19,"小说");
books[1]=new book("西游记","吴承恩",19,"小说");
books[2]=new book("红楼梦","曹雪芹",19,"小说");
usedSize=3;
}
public book getBook(int pos){
return books[pos]; //找书
}
public void setBook(int pos,book Book){
books[pos]=Book; //增加书
}
public void setUsedSize(int size){
usedSize=size; //实时修改当前书架上书的个数
}
public int getUsedSize(){
//实时获取当前书的个数
return usedSize;
}
}
operation包(实现具体的功能)
AddOperation:
package operation;
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");
Scanner scanner = new Scanner(System.in);
System.out.println("请输入图书的名字:");
String name=scanner.nextLine();
System.out.println("请输入图书的作者:");
String author=scanner.nextLine();
System.out.println("请输入图书的类型:");
String type=scanner.nextLine();
System.out.println("请输入图书的价格:");
int price=scanner.nextInt();
book Book=new book(name,author,price,type);
int currentSize=Booklist.getUsedSize();
Booklist.setBook(currentSize,Book);
Booklist.setUsedSize(currentSize+1);
System.out.println("新增图书成功");
}
}
BorrowOperation :
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("请输入借阅图书的名字");
Scanner scanner = new Scanner(System.in);
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)) {
Book.setBorrowed(true);
System.out.println("借阅成功");
return;
}
}
}
}
DelOperation:
package operation;
import book.book;
import book.booklist;
import sun.security.provider.certpath.CertId;
import java.util.Scanner;
public class DelOperation implements IOperation{
@Override
public void work(booklist Booklist) {
System.out.println("请输入删除图书的名字");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
int currentSize = Booklist.getUsedSize();
int SIZE=0;
for (int i = 0; i < currentSize; i++) {
book Book = Booklist.getBook(i);
if (Book.getName().equals(name)) {
SIZE=i;
break;
}
}
for(int i=SIZE;i<currentSize-1;i++){
book Book= Booklist.getBook(i+1);
Booklist.setBook(i,Book);
Booklist.setUsedSize(currentSize-1);
System.out.println("删除成功");
}
}
}
DisplayOperation:
package operation;
import book.book;
import book.booklist;
public class DisplayOperation implements IOperation{
@Override
public void work(booklist Booklist) {
int currentSize = Booklist.getUsedSize();
for (int i = 0; i < currentSize; i++) {
book Book = Booklist.getBook(i);
System.out.println(Booklist.getBook(i));
}
}
}
ExitOperation:
package operation;
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:
import java.util.Scanner;
public class FindOperation implements IOperation{
@Override
public void work(booklist Booklist) {
System.out.println("查找图书");
int currentSize = Booklist.getUsedSize();
System.out.println("请输入图书的名字");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
for (int i = 0; i < currentSize; i++) {
book Book = Booklist.getBook(i);
if (Book.getName().equals(name)) {
System.out.println("找到了这本书");
System.out.println(Book);
return;
}
}
System.out.println("没有你要找的这本书");
}
}
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");
System.out.println("请输入归还图书的名字");
Scanner scanner = new Scanner(System.in);
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)) {
Book.setBorrowed(false);
System.out.println("归还成功");
return;
}
}
}
}
接口: IOperation
package operation;
import book.booklist;
public interface IOperation {
void work(booklist Booklist);
}
user包(管理员 用户 main方法)
AdminUser:
package user;
import book.*;
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 DisplayOperation(),
};
}
public int menu(){
System.out.println("hello"+this.name+"欢迎来到图书小练习");
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("请输入你的操作");
Scanner scanner=new Scanner(System.in);
int choice= scanner.nextInt();
return choice;
}
}
NormalUser:
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 ReturnOperation(),
};
}
public int menu(){
System.out.println("hello"+this.name+"欢迎来到图书小练习");
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("请输入你的操作");
Scanner scanner=new Scanner(System.in);
int choice= scanner.nextInt();
return choice;
}
}
User:
package user;
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){
this.iOperations[choice].work(Booklist);
}
}
main方法:
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 name=scanner.nextLine();
System.out.println("请输入你的身份:1.管理员 2.用户");
int choice=scanner.nextInt();
if(choice==1){
return new AdminUser(name) ;
}
else {
return new NormalUser(name);
}
}
public static void main(String[] args) {
booklist Booklist = new booklist();
User user = login();//登录
while(true) {
int choice = user.menu(); //动态绑定
user.doOperation(choice, Booklist);
}
}
}
总结
这个小程序可以加深我们对继承封装和多态的理解,可以让我们更熟悉语法。
本篇文章内容结束,感谢大家观看。如果意见或建议,可以在评论区留言,您的点赞是我更新的动力。我们下篇文章再见。