图书管理系统的实现

一、系统的介绍

进入图书管理系统的用户分为：管理员用户和普通用户。
管理员用户所执行的操作有：查找图书、新增图书、删除图书、显示图书、退出系统。
普通用户所执行的操作有：查找图书、借阅图书、归还图书、退出系统。

二、各模块代码的实现

1、创建接口

各操作类都要实现该接口，以便后期组织各操作类的对象：

package operation;import Book.BookList;public interface IOperation {void work(BookList bookList);
}

2、创建Book包

Book包里面存放book类及BookList类，相关代码如下：

2.1 book类代码

package Book;public class book {private String name;private String author;private int price;private String type;private boolean isBorrowed;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 isBorrowed() {return isBorrowed;}public void setBorrowed(boolean borrowed) {isBorrowed = borrowed;}@Overridepublic String toString() {return "Book{" +"name='" + name + '\'' +", author='" + author + '\'' +", price=" + price +", type='" + type + '\'' +( (isBorrowed == true)?", 已被借出":", 未被借出")//", isBorrowed=" + isBorrowed++'}';}
}

2.2 BookList类

BookList类是用来实现存放图书的功能的，相当于书架。在这里我设置的书架上最多能存放10本书（ int DEFAULT_CAPACITY = 10;），并且书架上已存有三国演义、西游记、红楼梦三本书。

package Book;public class BookList {private book[] books;private int usedSize;  //记录当前书架上实际存放的书的数量private static final int DEFAULT_CAPACITY = 10;public BookList() {this.books = new book[DEFAULT_CAPACITY];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.usedSize = 3;}public book getBook(int pos) {return books[pos];}public void setBooks(int pos, book book) {this.books[pos] = book;}public int getUsedSize() {return usedSize;}public void setUsedSize(int usedSize) {this.usedSize = usedSize;}public book[] getBooks() {return books;}
}

3、创建operation包

operation包里面存放实现对图书进行操作的类，相关代码如下：

3.1 AddOperation类

该类实现新增图书的功能

package operation;
import Book.BookList;
import Book.book;
import java.util.Scanner;public class AddOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("新增图书");Scanner scanner = new Scanner(System.in);System.out.println("请输入书名：");String name = scanner.nextLine();System.out.println("请输入作者：");String author = scanner.nextLine();System.out.println("请输入类型：");String type = scanner.nextLine();System.out.println("请输入价格：");int price = scanner.nextInt();book book = new book(name,author,price,type);//检查数组中有没有 这本书int currentSize = bookList.getUsedSize();for(int i = 0;i<currentSize;i++) {book book1 = bookList.getBook(i);if(book1.getName().equals(name)) {System.out.println("已有这本书，不再进行存放了！");return;}}if(currentSize==bookList.getBooks().length) {System.out.println("书架满了！");}else {bookList.setBooks(currentSize,book);bookList.setUsedSize(currentSize+1);}}
}

3.2 DelOperation类

该类实现删除图书的功能

package operation;
import Book.BookList;
import Book.book;
import java.util.Scanner;public class DelOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("删除图书");Scanner scanner = new Scanner(System.in);System.out.println("请输入你要删除的图书：");String name = 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(name)) {pos = i;break;}}if (i>=currentSize) {System.out.println("没有你要删除的图书!");return;}//删除图书int j = pos;for (;j<currentSize-1;j++) {bookList.setBooks(j,bookList.getBook(j+1));}bookList.setBooks(j,null);bookList.setUsedSize(currentSize-1);}
}

3.3 ShowOperation类

该类实现显示图书的功能

package operation;
import Book.BookList;
import Book.book;
public class ShowOperation implements IOperation{@Overridepublic 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);}}
}

3.4 BorrowOperation类

该类实现普通用户借阅图书的功能

package operation;
import Book.BookList;
import Book.book;
import java.util.Scanner;public class BorrowOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("借阅图书");Scanner scanner = new Scanner(System.in);System.out.println("请输入你要借阅的图书：");String name = scanner.nextLine();int currenSize = bookList.getUsedSize();int i=0;for (;i<currenSize;i++) {book book = bookList.getBook(i);if(book.getName().equals(name)) {book.setBorrowed(true);System.out.println("借阅成功！");System.out.println(book);return;}}if (i == currenSize) {System.out.println("没有你要借阅的图书！");}}
}

3.5 ReturnOperation类

该类实现普通用户归还图书的功能

package operation;
import Book.BookList;
import Book.book;import java.util.Scanner;public class ReturnOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("归还图书");Scanner scanner = new Scanner(System.in);System.out.println("请输入你要归还的图书：");String name = scanner.nextLine();int currenSize = bookList.getUsedSize();int i=0;for (;i<currenSize;i++) {book book = bookList.getBook(i);if(book.getName().equals(name)) {book.setBorrowed(false);System.out.println("归还成功！");System.out.println(book);return;}}System.out.println("你归还的图书不存在！");}
}

3.6 FindOperation类

该类实现查找图书的功能

package operation;
import Book.BookList;
import Book.book;
import java.util.Scanner;public class FindOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("查找图书");Scanner scanner = new Scanner(System.in);System.out.println("请输入你要查找的图书：");String name = scanner.nextLine();int currenSize = bookList.getUsedSize();int i = 0;for (;i<currenSize;i++) {book book = bookList.getBook(i);if(book.getName().equals(name)) {System.out.println("找到了，信息如下：");System.out.println(book);return;}}if (i >= currenSize) {System.out.println("你要找的书不存在！");}}
}

3.7 ExitOperation类

该类实现退出程序的功能

package operation;
import Book.BookList;
public class ExitOperation implements IOperation{@Overridepublic void work(BookList bookList) {System.out.println("退出程序");System.exit(0);}
}

4、创建user包

user包里面装入User类、NomalUser类和AdminUser类， NomalUser类（普通用户）和AdminUser类（管理员用户）分别继承User类。

4.1 User类

package user;import Book.BookList;
import operation.IOperation;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);}
}

4.2 NomalUser类

package user;
import operation.IOperation;
import operation.*;
import java.util.Scanner;
public class NomalUser extends User{public NomalUser(String name) {super(name);this.iOperation = new IOperation[]{new ExitOperation(),new FindOperation(),new BorrowOperation(),new ReturnOperation()};}public int menu() {System.out.println("**********普通用户******");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("**********************");Scanner scanner = new Scanner(System.in);System.out.println("请输入你的操作：");int choice = scanner.nextInt();return choice;}
}

4.3 AdminUser类

package user;
import operation.IOperation;
import operation.*;
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 ShowOperation(),};}public int menu() {System.out.println("**********管理员用户*****");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("**********************");Scanner scanner = new Scanner(System.in);System.out.println("请输入你的操作：");int choice = scanner.nextInt();return choice;}
}

三、主方法的实现

import Book.BookList;
import user.AdminUser;
import user.NomalUser;
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：普通用户->");int choice = scanner.nextInt();if(choice == 1){return new AdminUser(name);}else {return new NomalUser(name);}}public static void main(String[] args) {BookList bookList = new BookList();User user = login();while (true) {int choice = user.menu();// System.out.println("choice:"+choice);user.doOperation(choice,bookList);}}
}

这个图书管理系统的缺点：