实现的基本功能：
登录时，需要输入姓名，然后选择作为管理者还是普通用户。选择成功后选择想要实现的功能。管理者的目录下方有有五个功能，而普通用户有4个功能，如下图
首先我们要建立Book这个类，里面包含书本的详细信息
public class Book {
private String name;
private String author;
private int price;
private String type;
private boolean isLend;
public Book(String name, String author, int price, String type) {
this.name = name;
this.author = author;
this.price = price;
this.type = type;
}//并不需要将是否借出作为参数，因为每一本书在增添的时候都默认没有借出
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 isLend() {
return isLend;
}
public void setLend(boolean lend) {
isLend = lend;
}
public String toString() {
return "book{" +
"书名 " + name + " " +
"作者 " + author + " " +
"价格 " + price +
"类型 " + type + " " +
"是否借出 " + (isLend?"已借出":"未借出") +
'}';
}
}
要设置一个书架，里面建立一个数组来放书：
private Book[] books=new Book[10];
private int usedSize;
public BookList() {
books[0]=new Book("三国演义","罗贯中",10,"小说");
books[1]=new Book("西游记","吴承恩",12,"小说");
books[2]=new Book("红楼梦","曹雪芹",11,"小说");
this.usedSize =3;
}
public int getUsedSize() {
return usedSize;
}
public void setUsedSize(int usedSize) {
this.usedSize = usedSize;
}
public Book[] getBooks() {
return books;
}
public void setBooks(Book[] books) {
this.books = books;
}
public Book getBook(int pos){
return books[pos];
}
public void setBook(Book book,int pos){
books[pos]=book;
}
public boolean isFull(){
if(this.usedSize==books.length){
return true;
}else {
return false;
}
}
}
设置主函数：
public class Main {
public static User login(){
System.out.println("请输入你的名字");
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 AdminUser(name);
}else {
return new NormalUser(name);
}
}
public static void main(String[] args) {
BookList bookList=new BookList();
User user=login();
while(true) {
int choice = user.menu();
user.doOperation(choice, bookList);
}
}
面对的有两类人，一类为普通用户，另一类为管理者，建立两个类，他们均继承User这个类，因为这个User这个类不用实现对象，所以为一个抽象类
public abstract class User {
private String name;
IOperation [] iOperations=new IOperation[]{};
public User(String name) {
this.name = name;
}
public abstract int menu();
public void doOperation(int choice, BookList bookList){
this.iOperations[choice].work(bookList);
}
}
public class AdminUser extends User{
public AdminUser(String name) {
super(name);
this.iOperations=new IOperation[]{new ExitSystem(),
new FindBook(),new AddBook(),new DelBook(),new ShowBook()};
}
public int menu(){
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("请输入你操作");
Scanner scanner=new Scanner(System.in);
int choice=scanner.nextInt();
return choice;
}
}
public class NormalUser extends User {
public NormalUser(String name) {
super(name);
this.iOperations=new IOperation[]{new ExitSystem(),
new FindBook(),new LendBook(),new ReturnBook()};
}
public int menu(){
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("0,退出系统");
Scanner scanner=new Scanner(System.in);
int choice=scanner.nextInt();
return choice;
}
}
实现各个功能：
public interface IOperation {
void work(BookList bookList);
}
新增图书
public class AddBook implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("新增图书");
if (bookList.isFull()==true){
System.out.println("满了不能放");
return;
}
System.out.println("请输入新增图书的书名：");
Scanner scanner=new Scanner(System.in);
String bookName=scanner.nextLine();
System.out.println("请输入新增书的作者");
String author=scanner.nextLine();
System.out.println("请输入新增书的价格");
int price=scanner.nextInt();
scanner.nextLine();
System.out.println("请输入新增书的类型");
String type=scanner.nextLine();
Book book=new Book(bookName,author,price,type);
int current=bookList.getUsedSize();
bookList.setBook(book,current);
bookList.setUsedSize(current+1);
System.out.println("新增图书成功");
}
}
删除图书
public class DelBook implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("删除图书");
System.out.println("请输入要删除的书名：");
Scanner scanner=new Scanner(System.in);
String bookName=scanner.nextLine();
int currentSize= bookList.getUsedSize();
int pos=-1;
int i = 0;
for (; i <currentSize ; i++) {
Book book=bookList.getBook(i);
if(book.getName().equals(bookName)){
System.out.println("找到这本书，开始删除");
pos=i;
break;
}
}
if(i>=currentSize){
System.out.println("没有找到这本书");
return;
}
for (int j = pos; j <currentSize-1 ; j++) {
Book book=bookList.getBook(j+1);
bookList.setBook(book,j);
}
bookList.setUsedSize(currentSize-1);
bookList.setBook(null,currentSize-1);
System.out.println("删除成功");
}
}
退出系统
public class ExitSystem implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("退出系统");
for (int i = 0; i < bookList.getUsedSize(); i++) {
bookList.setBook(null,i);
}
System.exit(0);
}
}
查找图书
public class FindBook implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("查找图书");
System.out.println("请输入要查找的书名：");
Scanner scanner=new Scanner(System.in);
String bookName=scanner.nextLine();
int currentSize= bookList.getUsedSize();
for (int i = 0; i <currentSize ; i++) {
Book book=bookList.getBook(i);
if(book.getName().equals(bookName)){
System.out.println("找到了这本书");
System.out.println(book);
return;
}
}
System.out.println("没有找到这本书");
}
}
借书
public class LendBook implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("借书");
System.out.println("请输入要借阅的书名：");
Scanner scanner=new Scanner(System.in);
String bookName=scanner.nextLine();
int currentSize= bookList.getUsedSize();
for (int i = 0; i <currentSize ; i++) {
Book book=bookList.getBook(i);
if(book.getName().equals(bookName)){
book.setLend(true);
System.out.println("借阅成功");
return;
}
}
System.out.println("借阅失败");
}
}
归还图书
public class ReturnBook implements IOperation{
@Override
public void work(BookList bookList) {
System.out.println("ReturnBook");
System.out.println("请输入要归还的书名：");
Scanner scanner=new Scanner(System.in);
String bookName=scanner.nextLine();
int currentSize= bookList.getUsedSize();
for (int i = 0; i <currentSize ; i++) {
Book book=bookList.getBook(i);
if(book.getName().equals(bookName)){
book.setLend(false);
System.out.println("归还成功");
return;
}
}
System.out.println("归还失败");
}
}
显示图书
public class ShowBook 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.getBook(i);
System.out.println(book);
}
}
}
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