import java.util.Scanner;

/**
 * 这是一个图书查询的程序 写程序之前逻辑一定清晰，然后再去写，再进行优化测试，然后不断改进
 */
public class Main {
    private static Scanner input = new Scanner(System.in);

    public static void main(String[] args) {
        String[] books = { "高数", "线代", "汇编语言", "数据结构" };
        while (true) {
            System.out.println("输入命令：1-按照名称查找图书；2-按照序号查找图书");
            String firstInput = input.next();
            try {
                switch (firstInput) {
                case "1":
                    System.out.println("book:" + getBookName(books));

                    continue;
                case "2":
                    System.out.println("book:" + getBookNameByNumber(books));

                    continue;
                default:
                    System.out.println("输入有误，请重写输入！！");
                    continue;
                }
            } catch (Exception bne) {
                System.out.println(bne.getMessage());
                continue;
            }
        }

    }

    private static String getBookName(String[] books) throws Exception {
        System.out.println("请输入图书名称：");
        String book = input.next();
        for (int i = 0; i < books.length; i++) {
            if (book.equals(books[i])) {
                return book;
            }
        }
        throw new Exception("不存在这本书！");
    }

    private static String getBookNameByNumber(String[] books) throws Exception {
        // int bookSum = books.length;
        while (true) {
            System.out.println("请输入图书序号：");
            try {
                int index = input.nextInt();
                if (index < 0) {
                    System.out.println("请输入自然数序号！");
                    continue;
                }
                return books[index];
            } catch (java.util.InputMismatchException i) {

                System.out.println("请输入自然数序号！");
                input = new Scanner(System.in);
                continue;

            } catch (ArrayIndexOutOfBoundsException e) {

                Exception bookNotExist = new Exception("不存在这本书！");
                bookNotExist.initCause(e);
                throw bookNotExist;
            }

        }
    }
}