最终效果
图书管理系统
book包
该包中有两个类,用来对书进行管理。
Book类
从开头视频可以看见,每本书有书名,作者,类型,价格,是否借出。我们将它们定义出来,并有快捷键获得get和set方法。
在生成一个构造方法,含书名,作者,类型,价格。
然后再快捷键重写Object的equals方法,重写toString方法。
注意:
因为直接重写的equals方法是对所有成员变量都进行对比,但是我们不需要对比借出状态(如果对比了那还怎么进行借阅和归还操作)。
还有toString方法我们要将借出的boolean类型转换为是否借出输出,就需要改为3目操作符( (this.isBorrowed)?", 已借出":", 未借出")
最终该类代码就是:
java
package book;
import java.util.Objects;
public class Book {
private String name;
private String author;
private String type;
private int price;
private boolean isBorrowed;
public Book(String name, String author, String type, int price) {
this.name = name;
this.author = author;
this.type = type;
this.price = price;
}
public boolean isBorrowed() {
return isBorrowed;
}
public void setBorrowed(boolean borrowed) {
isBorrowed = borrowed;
}
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 String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Book book = (Book) o;
return price == book.price && Objects.equals(name, book.name) && Objects.equals(author, book.author) && Objects.equals(type, book.type);
}
@Override
public String toString() {
return "Book{" +
"name='" + name + '\'' +
", author='" + author + '\'' +
", type='" + type + '\'' +
", price=" + price +
( (this.isBorrowed)?", 已借出":", 未借出")+
'}';
}
}
BookList类
在这个类中我们就将书给管理起来(简易顺序表),所以成员就用一个Book数组来存书,在用一个usedSize来表示存入书的数目,提供get和set方法。并在构造方法中初始化几本书。
BookList类最终代码:
java
package book;
public class BookList {
private int usedSize;
Book[] books = new Book[10];
public int getUsedSize() {
return usedSize;
}
public BookList() {
this.books[0] = new Book("西游记","吴承恩","小说",66);
this.books[1] = new Book("红楼梦","曹雪芹","小说",77);
this.books[2] = new Book("三国演义","罗贯中","小说",88);
this.books[3] = new Book("坤拳录","cxk","修仙秘籍",25);
this.usedSize = 4;//在创建书架时直接默认存在3本书
}
public Book[] getBooks() {
return books;
}
public void setBooks(Book[] books) {
this.books = books;
}
public void setUsedSize(int usedSize) {
this.usedSize = usedSize;
}
}
user包
该包用来管理使用者。含有3个类,抽象类User来作为管理员类和普通用户类的父类抽取共性。
User类
每一个管理员和普通用户都有名字,还有展示效果中选择了自己身份后会跳出菜单来让你选择操作。再用一个方法来表示调用的操作(因为我们将每一个操作封装为一个类来操作),用IOpertion数组来存入子类的操作。
User类最终代码:
java
package user;
import book.BookList;
import operation.IOperation;
public abstract class User {
String name;
IOperation[] iOperations;
public abstract int menu();
public abstract void doOpertion(int choice, BookList bookList);
public User(String name) {
this.name = name;
}
}
AdmiUser类(管理员类)
该类继承User类并且将父类的抽象方法重写,在该方法中调用对应类的具体工作方法(自己实现的work方法)。并且在自己的构造方法中将IOpertion接口实现的数组初始化(根据提供的操作对应的数字,数字对应下标初始为对应操作实现的类)。
AdmiUser类最终代码:
java
package user;
import book.BookList;
import operation.*;
import java.util.Scanner;
import java.util.Scanner;
public class AdmiUser extends User {
public AdmiUser(String name) {
super(name);
this.iOperations = new IOperation[]{
new ExitOpertion(),
new FindOpertion(),
new AddOpertion(),
new DeletOpertion(),
new ShowOpertion()
};
}
@Override
public void doOpertion(int choice, BookList bookList){
this.iOperations[choice].work(bookList);
}
@Override
public int menu() {
int choice = -1;
while(true) {
System.out.println("欢迎 " + this.name + " 来到图书管理系统");
System.out.println("--------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("请输入您的操作");
Scanner scanner = new Scanner(System.in);
choice = scanner.nextInt();
if(choice >=0 && choice <= 4){
break;
}else {
System.out.println("输入错误");
}
}
return choice;
}
}
NormalUser类(普通用户类)
在该类中与管理员类实现一致,只是在设计实现自己的操作时改一下就好。
NormalUser类最终代码:
java
package user;
import book.BookList;
import operation.*;
import java.util.Scanner;
public class NormalUser extends User{
public NormalUser(String name) {
super(name);
this.iOperations = new IOperation[]{
new ExitOpertion(),
new FindOpertion(),
new BorrowOpertion(),
new ReturnOpertion(),
new ShowOpertion()
};
}
@Override
public int menu() {
int choice = -1;
while(true) {
System.out.println("欢迎 " + this.name + " 来到图书管理系统");
System.out.println("--------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("4.展示图书");
System.out.println("0.退出系统");
System.out.println("-----------------------------");
System.out.println("请输入您的操作");
Scanner scanner = new Scanner(System.in);
choice = scanner.nextInt();
if(choice >=0 && choice <= 4){
break;
}else {
System.out.println("输入错误");
}
}
return choice;
}
@Override
public void doOpertion(int choice, BookList bookList) {
this.iOperations[choice].work(bookList);
}
}
opeeration包
在改包中实现具体的操作,对书的增加,删除,借阅,归还,查找,展示,退出程序。这7个类在加上接口。
IOperation接口
这个接口就抽取一个work的共性方法。
最终代码:
java
package operation;
import book.BookList;
public interface IOperation {
void work(BookList bookList);
}
FindOpertion类(查找操作)
在该类中实现IOpertion接口,实现work方法,
先将要查找的书用临时变量存起来,然后遍历书架已有的书看是否有这本书,有就打印。
FindOpertion类最终代码:
java
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class FindOpertion implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("请输入要查找书的书名:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
System.out.println("请输入要查找书的作者:");
String author = scanner.nextLine();
System.out.println("请输入要查找书的类型:");
String type = scanner.nextLine();
System.out.println("请输入要查找书的价格:");
int price = scanner.nextInt();
Book book = new Book(name,author,type,price);
//看这本书是否已经存在
for (int i = 0; i < bookList.getUsedSize(); i++) {
if(bookList.getBooks()[i].equals(book)){
System.out.println(bookList.getBooks()[i].toString());
return;
}
}
System.out.println("没有该书");
}
}
AddOpertion类(增加操作)
该操作与查找操作实现一致,只是在找到后就告诉已经有这本书了,没找到就添加,并将usedSize加1.
AddOpertion类最终代码
java
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class AddOpertion implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("请输入要添加书的书名:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
System.out.println("请输入要添加书的作者:");
String author = scanner.nextLine();
System.out.println("请输入要添加书的类型:");
String type = scanner.nextLine();
System.out.println("请输入要添加书的价格:");
int price = scanner.nextInt();
Book book = new Book(name,author,type,price);
//看这本书是否已经存在
for (int i = 0; i < bookList.getUsedSize(); i++) {
if(bookList.getBooks()[i].equals(book)){
System.out.println("该书已经存在");
return;
}
}
//存入
bookList.getBooks()[bookList.getUsedSize()] = book;
bookList.setUsedSize(bookList.getUsedSize() + 1);
System.out.println("添加成功");
}
}
DeletOpertion类(删除操作)
该操作与查找操作实现一致,只是在找到后记录这个下标,并且再用一个循环(注意结束条件)用后面的书覆盖前面的,将usedSize减1,没找到就输出没有该书。
DeletOpertion类最终代码
java
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class DeletOpertion implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("请输入要删除书的书名:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
System.out.println("请输入要删除书的作者:");
String author = scanner.nextLine();
System.out.println("请输入要删除书的类型:");
String type = scanner.nextLine();
System.out.println("请输入要删除书的价格:");
int price = scanner.nextInt();
Book book = new Book(name,author,type,price);
//看这本书是否已经存在,记住位置
int now = -1;
for (int i = 0; i < bookList.getUsedSize(); i++) {
if(bookList.getBooks()[i].equals(book)){
now = i;
break;
}
}
//覆盖
if(now != -1){
for (int i = now; i < bookList.getUsedSize() - 1; i++) {
bookList.getBooks()[i] = bookList.getBooks()[i+1];
}
bookList.setUsedSize(bookList.getUsedSize() - 1);
System.out.println("删除成功");
}else{
System.out.println("没有该书");
}
}
}
BorrowOpertion类(借阅操作)
该操作与查找操作实现一致,只是在找到(这里的找到指有这本书并且状态是未借出)后就将这本书的状态改为已借出(将isBorrowed改为true),有但是已被借出就输出该书已被借出,没找到就输出没有。
BorrowOpertion类最终代码:
java
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class BorrowOpertion implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("请输入要借阅书的书名:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
System.out.println("请输入要借阅书的作者:");
String author = scanner.nextLine();
System.out.println("请输入要借阅书的类型:");
String type = scanner.nextLine();
System.out.println("请输入要借阅书的价格:");
int price = scanner.nextInt();
Book book = new Book(name,author,type,price);
//看这本书是否有并未被借出,有就改状态
for (int i = 0; i < bookList.getUsedSize(); i++) {
if(bookList.getBooks()[i].equals(book)
&& !bookList.getBooks()[i].isBorrowed()){
bookList.getBooks()[i].setBorrowed(true);
System.out.println("借阅成功");
return;
} else if (bookList.getBooks()[i].equals(book)
&& bookList.getBooks()[i].isBorrowed()) {
System.out.println("该书以被借出");
return;
}
}
System.out.println("没有该书");
}
}
ReturnOpertion 类(归还操作)
该操作与查找操作实现一致,只是在找到(这里的找到指有这本书并且状态是已借出)后就将这本书的状态改为未借出(将isBorrowed改为false),有但是未被借出就输出该书未被借出,没找到就输出没有。
ReturnOpertion 类最终代码:
java
package operation;
import book.Book;
import book.BookList;
import java.util.Scanner;
public class ReturnOpertion implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("请输入要归还书的书名:");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
System.out.println("请输入要归还书的作者:");
String author = scanner.nextLine();
System.out.println("请输入要归还书的类型:");
String type = scanner.nextLine();
System.out.println("请输入要归还书的价格:");
int price = scanner.nextInt();
Book book = new Book(name,author,type,price);
//看这本书是否有并未被借出
for (int i = 0; i < bookList.getUsedSize(); i++) {
if(bookList.getBooks()[i].equals(book)
&& !bookList.getBooks()[i].isBorrowed()){
System.out.println("该书并未被借出");
return;
} else if (bookList.getBooks()[i].equals(book)
&& bookList.getBooks()[i].isBorrowed()) {
bookList.getBooks()[i].setBorrowed(false);
System.out.println("归还成功");
return;
}
}
System.out.println("没有该书");
}
}
ShowOpertion类(展示操作)
该类就只需遍历并输出就行。
java
package operation;
import book.BookList;
public class ShowOpertion implements IOperation{
@Override
public void work(BookList bookList) {
for (int i = 0; i < bookList.getUsedSize(); i++) {
System.out.println(bookList.getBooks()[i].toString());
}
}
}
ExitOpertion类(退出操作)
直接调用退出函数就行
java
package operation;
import book.BookList;
public class ExitOpertion implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("退出成功");
System.exit(0);
}
}
Main类
在该类中写一个login函数来确定身份向上转型给User.
main主函数将操作串起来:
java
import book.BookList;
import user.AdmiUser;
import user.NormalUser;
import user.User;
import java.util.Scanner;
public class Main {
//使用这个函数来确定访问者身份
private 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.普通用户");
int choice = scanner.nextInt();
if(choice == 1){
return new AdmiUser(name);
} else if (choice == 2) {
return new NormalUser(name);
}else {
System.out.println("输入错误");
return null;
}
}
public static void main(String[] args) {
BookList bookList = new BookList();
User user = login();
while( user == null){
user = login();
}//使用循环保证输入身份正确
while (true){
int choice = user.menu();
user.doOpertion(choice,bookList);
}
}
}