目录
实现的样子
大致思路
代码 (按照这个目录创建包)
首先是book包下,有两个类
book类
bookList类
然后是operation包下,有7个类和1个接口
AddOperation类
BorrowOperation类
DelOperation类
DisplayOperation类
ExitOperation类
FindOperation类
ReturnOperation类
IOperation接口
最后是user包下,有3个类
AdminUser类
NormalUser类
User类
还有一个外边的Main类
Main类
实现的样子
首先让我们来看一下系统实现以后大致的样子
如果说要做一个大致这样子的图书管理系统,那么我们要有大致的思路:
首先我们要创建三个包,user,operation,book
大致思路
- 要有书对吧,所以创建Book类存放每本书的基本信息
- 图书馆有很多书对吧,所以创建Books类存放好几本书,里面放了一个Book类型的数组和一个usedSize表示总共书的数目
-
有两种不同的人,管理员和用户,总共有7个功能,也就是要写7个功能类
-
然后我们发现,这7个功能类都要定义这么一个work方法,而且都是对BookList进行操作的,因此我们可以设置一个接口IOperation,让这些功能类实现这个接口
-
然后我们再看User这个包,这里面有两种用户,一个是管理员,一个是普通用户,注意到他们都有各自的菜单,同时他们都有姓名等一些公共的属性,所以这里我们可以定义一个User父类,让AdminUser和 NormalUser去继承这个类。
- 注意到这里的菜单不一样,可以分别再AdminUser和NormalUser里面都定义一个menu方法,但是这样不灵活,所以我们可以在User类里面定义一个空的menu方法,然后让另外两个类去实现,以后还可以方便进行多态(动态绑定),更加灵活,注意到menu是空的,所以可以设置成abstract方法,同时User类也要改为abstract类。
- 注意这里menu显示了以后要输入一个数字代表你要使用的功能,所以需要返回一个数字代表你所使用的功能,这里可以把menu方法定义为返回值为int型的方法
- 现在我们在最外面新建一个Main类,里面写main方法,在main方法之前我们写一个login方法,用来读入用户的名称以及他的用户类型,如果是管理员,返回一个AdminUser对象,如果是普通用户,返回一个NormalUser对象,这里注意把login()方法的返回值设置为User对象,然后再main方法中User user = login;然后user.menu();显示出菜单,这里就使用了多态,通过返回值让父类引用引用了子类的对象,同时父类的引用调用了子类重写过的同名方法。
- 最巧妙的一步,我们现在的user已经完成了动态绑定,相当于已经知道了他是管理员还是普通用户,接下来要做的就是根据choice的值来调用相应的操作类。
现在你只有一个user,所以根据choice调用不同的操作这个方法自然也应该在user这个类中。首先在User内部定义一个成员变量,操作接口的数组,用于存放不同的操作类
然后在AdminUser和NormalUser按顺序初始化这些操作类,这里相当于IOperation接口发生了向上转型
在User里面定义doOperation方法,根据choice调用不同操作类的work方法对booklist数组进行操作
10.由于选择功能使用一次以后,不能直接退出,需要再次显示菜单,所以我们将选择菜单和调用相应方法这两个语句写到死循环中
11.接下来就只需要写那几个功能类就可以了
12.ExitOperation,System.exit(0);即可
13.AddOperation,很简单,让用户输入图书相应的信息,然后新建一个book类,初始化放到bookList的usedSize位置即可,之后别忘了更新usedSize
14.FindOperationn,fori遍历即可,每一次遍历可以先定义一个book对象,然后比较该对象的名称与输入的名称是否一样,如果找到了,提示并打印,然后直接return;这样就不用设置flag了,如果走出了for循环还没有return,那么就说明没找到,提示没找到即可。
15.DisplayOperation,fori遍历即可
16.BorrowOperation,ReturnOperation,对相应isBorrowed变量进行相应操作即可
代码 (按照这个目录创建包)
代码亲测能正常运行,如果不想自己慢慢新建类的话,可以点击下面链接自取。不过其实新建类也挺快的,要注意不要把类的名字建错。有什么不会弄的都可以评论问我。
Library.rar-Java文档类资源-CSDN下载
、
首先是book包下,有两个类
book类
package Library.book;public class Book {private String name;private String author;private int price;private String type;private boolean isBorowed; //默认是flase,默认没有被借,所以可以不用初始化public Book(String name, String author, int price, String type) {this.name = name;this.author = author;this.price = price;this.type = type;//默认是flase,默认没有被借,所以可以不用初始化}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 isBorowed() {return isBorowed;}public void setBorowed(boolean borowed) {isBorowed = borowed;}@Overridepublic String toString() {return "book{" +"name='" + name + '\'' +", author='" + author + '\'' +", price=" + price +", type='" + type + '\'' +", isBorowed=" + isBorowed +'}';}
}
bookList类
package Library.book;public class BookList {private Book[] books = new Book[10];private int usedSize = 0;public BookList(){books[0] = new Book("游戏人生","榎宫祐",12,"轻小说");books[1] = new Book("见面5秒开始战斗","肠才藏",20,"漫画");books[2] = new Book("碧蓝之海","井上竖二",25,"漫画");this.usedSize = 3;}public Book getBook(int pos) { //取pos位置的那本书return this.books[pos];}public void setBook(int pos, Book book) { //将pos位置的书置为bookthis.books[pos] = book;}public int getUsedSize() {return usedSize;}public void setUsedSize(int usedSize) {this.usedSize = usedSize;}
}
然后是operation包下,有7个类和1个接口
AddOperation类
package Library.operation;import Library.book.Book;
import Library.book.BookList;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/18* Time: 22:43* Description:新增图书*/
public class AddOperation implements IOperation {public void work(BookList bookList){Scanner scanner = new Scanner(System.in);System.out.println("新增图书");//只需要放到当前数组的usedSize位置System.out.println("请输入图书的名字:");String name = scanner.next();System.out.println("请输入图书的作者:");String author = scanner.next();System.out.println("请输入图书的价格:");int price = scanner.nextInt();System.out.println("请输入图书的类型:");String type = scanner.next();Book book = new Book(name,author,price,type);int curSize = bookList.getUsedSize();bookList.setBook(curSize,book);bookList.setUsedSize(curSize+1);System.out.println("图书添加成功!");}}
BorrowOperation类
package Library.operation;import Library.book.Book;
import Library.book.BookList;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:02* Description: 借阅书籍*/
public class BorrowOperation implements IOperation {public void work(BookList bookList){System.out.println("借阅书籍");Scanner scanner = new Scanner(System.in);System.out.println("请输入需要借阅的图书名称:");String name = scanner.next();for (int i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);if (book.getName().equals(name)){if (!book.isBorowed()){book.setBorowed(true); //如果找到该书,且该书没有被借阅,那就借阅成功System.out.println("图书借阅成功!");}else {System.out.println("该图书已被借阅!");}return;}}System.out.println("该图书不存在!"); //走到这里说明这本书不存在}
}
DelOperation类
package Library.operation;import Library.book.Book;
import Library.book.BookList;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:03* Description: 删除图书*/
public class DelOperation implements IOperation{public void work(BookList bookList){Scanner scanner = new Scanner(System.in);System.out.println("删除图书");System.out.println("请输入要删除的图书名称:");String name = scanner.next();int n = bookList.getUsedSize();for (int i = 0; i < n; i++) {Book book = bookList.getBook(i);if (book.getName().equals(name)){for (int j = i; j < n-1; j++) {bookList.setBook(j,bookList.getBook(j+1));}bookList.setUsedSize(n-1);System.out.println("图书删除成功!");return; //如果找到了并且删除成功,就return}}System.out.println("对不起,没有找到您需要删除的书!"); //如果没有for循环中没有return,那就是没有找到}
}
DisplayOperation类
package Library.operation;import Library.book.BookList;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:03* Description: 显示书籍*/
public class DisplayOperation implements IOperation {public void work(BookList bookList){System.out.println("显示书籍");for (int i = 0; i < bookList.getUsedSize(); i++) {System.out.println(bookList.getBook(i));}}
}
ExitOperation类
package Library.operation;import Library.book.BookList;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:04* Description: 退出系统*/
public class ExitOperation implements IOperation {public void work(BookList bookList){System.out.println("退出系统");System.exit(0); //退出系统}
}
FindOperation类
package Library.operation;import Library.book.Book;
import Library.book.BookList;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:04* Description: 查找图书*/
public class FindOperation implements IOperation{public void work(BookList bookList){Scanner scanner = new Scanner(System.in);System.out.println("查找图书");System.out.println("请输入图书的名称:");String name = scanner.next();for (int i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);if (book.getName().equals(name)){System.out.println("找到该图书!");System.out.println(book);return; //如果找到了,就直接return出去}}System.out.println("对不起,没有找到此书!"); //如果走到这一步,那么说明没有在for循环return出去,那就显示没找到}
}
ReturnOperation类
package Library.operation;import Library.book.Book;
import Library.book.BookList;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:04* Description: 归还图书*/
public class ReturnOperation implements IOperation{public void work(BookList bookList){System.out.println("归还图书");Scanner scanner = new Scanner(System.in);System.out.println("请输入需要归还的图书名称:");String name = scanner.next();for (int i = 0; i < bookList.getUsedSize(); i++) {Book book = bookList.getBook(i);if (book.getName().equals(name)){if (book.isBorowed()){book.setBorowed(false); //如果找到该书,且该书已被借阅,那就归还成功System.out.println("图书归还成功!");}else {System.out.println("该图书未被借阅!");}return;}}System.out.println("该图书不存在!"); //走到这里说明这本书不存在}
}
IOperation接口
package Library.operation;import Library.book.BookList;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:06* Description: No Description*/
public interface IOperation {void work(BookList bookList);
}
最后是user包下,有3个类
AdminUser类
package Library.user;import Library.operation.*;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:19* Description: No Description*/
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("========================================");System.out.println("尊贵的管理员-"+this.name+",欢迎使用本图书管理系统");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.显示所有图书");System.out.println("0.退出系统");System.out.println("========================================");System.out.print("请输入数字以使用相应的功能:");Scanner scanner = new Scanner(System.in);int n = scanner.nextInt();return n;}}
NormalUser类
package Library.user;import Library.operation.*;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:19* Description: No Description*/
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("========================================");System.out.println("尊贵的用户-"+this.name+",欢迎使用本图书管理系统");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("========================================");System.out.print("请输入数字以使用相应的功能:");Scanner scanner = new Scanner(System.in);int n = scanner.nextInt();return n;}}
User类
package Library.user;import Library.book.BookList;
import Library.operation.IOperation;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:18* Description: No Description*/
public abstract class User {protected String name;IOperation[] IOperations;public User(String name) {this.name = name;}public abstract int menu();public void doOperations(int choice, BookList bookList){IOperations[choice].work(bookList);}
}
还有一个外边的Main类
Main类
package Library;import Library.book.BookList;
import Library.user.AdminUser;
import Library.user.NormalUser;
import Library.user.User;import java.util.Scanner;/*** Created with IntelliJ IDEA.* User: 13498* Date: 2021/11/22* Time: 14:44* Description: No Description*/
public class Main {public static User login(){System.out.println("请输入您的姓名");Scanner scanner = new Scanner(System.in);String name = scanner.nextLine();System.out.println("请输入您的身份:1 -> 管理员 0 -> 普通用户");int n = scanner.nextInt();if (n == 1){return new AdminUser(name);}else {return new NormalUser(name);}}public static void main(String[] args) {BookList bookList = new BookList(); //准备了书籍User user = login(); //向上转型while(true){ //写成死循环,这样就会不断的调用菜单,直到选择退出系统int choice = user.menu(); //动态绑定调用menu方法,choice表示你的选择user.doOperations(choice,bookList);}}
}
OK,就这些了,代码能运行无bug,如果有什么地方出错了或者有什么不懂都可以评论问我。