一、operations包

我们的图书管理系统有很多具体的操作，为了后面方便多态，以及检验错误，所以我们实现一个具体的IOperation接口，每一个具体的操作去实现这个接口.

1. IOperation接口

package operations;

import book.BookList;

public interface IOperation {
    void work(BookList bookList);
}

2. AddOperation

增加图书：

package operations;

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! ");
        System.out.println("请输入要新增的图书的名字: ");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        System.out.println("请输入要新增的图书的作者: ");
        String author = scanner.nextLine();
        System.out.println("请输入要新增的图书的价格: ");
        int price = scanner.nextInt();
        System.out.println("请输入要新增的图书的类型: ");
        String type = scanner.nextLine();

        Book book = new Book(name,author,price,type);

        //1.获取当前书存放的位置
        int curSize = bookList.getUsedSize();
        //2.把书放在指定位置
        bookList.setBooks(book,curSize);
        //3.更新书的个数
        bookList.setUsedSize(curSize+1);

    }
}

3. BorrowOperation

借阅图书:

package operations;

import book.Book;
import book.BookList;

import java.util.Scanner;

public class BorrowOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("借阅图书! ");
        System.out.println("请输入要借阅的图书的名字: ");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        for (int i = 0; i < bookList.getUsedSize(); i++) {
            Book book = bookList.getPos(i);
            if(name.equals(book.getName())) {
                if(book.isBorrowed()) {
                    System.out.println("该书已经被借出! ");
                }else {
                    book.setBorrowed(true);
                    System.out.println("借阅图书成功! ");
                    return;
                }
            }
        }
        System.out.println("没有你要借阅的书! ");
    }
}

4. DelOperation

删除图书:

package operations;

import book.Book;
import book.BookList;

import java.util.Scanner;
public class DelOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("删除图书! ");
        System.out.println("请输入要删除的图书: ");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();

        //查找图书是否有此图书，记录下标
        int index = -1;
        for (int i = 0; i < bookList.getUsedSize(); i++) {
            Book book = bookList.getPos(i);
            if(name.equals(book.getName())) {
               index = i;
               break;
            }
        }
        if(index == -1) {
            System.out.println("没有 "+name+"这本书!");
            return;
        }
        for (int i = index; i < bookList.getUsedSize()-1; i++) {
            Book book = bookList.getPos(i+1);
            bookList.setBooks(book,i);
        }

        //删除的书,要置空
        bookList.setBooks(null, bookList.getUsedSize()-1);
        bookList.setUsedSize(bookList.getUsedSize()-1);
    }
}

5. DisplayOperation

显示图书:

package operations;

import book.Book;
import book.BookList;
public class DisplayOperation implements IOperation{
    @Override
    public void work(BookList bookList) {
        System.out.println("显示图书! ");
        for (int i = 0; i < bookList.getUsedSize(); i++) {
            Book book = bookList.getPos(i);
            System.out.println(book);
        }
    }
}

6. ExitOperation

退出图书：

package operations;

import book.BookList;
public class ExitOperation implements IOperation{
    @Override
    public void work(BookList bookList) {

        System.out.println("退出系统! ");
        System.exit(0);
    }
}

7. FindOperation

查找图书:

package operations;

import book.Book;
import book.BookList;

import java.util.Scanner;

public class FindOperation implements IOperation{
    @Override
    public void work(BookList bookList) {

        //查找图书
        System.out.println("查找图书! ");
        System.out.println("请输入要查找的图书: ");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        for (int i = 0; i < bookList.getUsedSize(); i++) {
            Book book = bookList.getPos(i);
            if(name.equals(book.getName())) {
                System.out.println("找到了! ");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有这本书! ");
    }
}

8. ReturnOperation

归还图书:

package operations;

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("请输入要归还的图书的名字: ");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        for (int i = 0; i < bookList.getUsedSize(); i++) {
            Book book = bookList.getPos(i);
            if(name.equals(book.getName())) {
                book.setBorrowed(false);
                System.out.println("归还图书成功! ");
                return;
            }
        }
        System.out.println("没有你要归还的书! ");
    }
}