package imooc;

import java.util.Scanner;

public class Book {
public static Scanner inputScanner = new Scanner(System.in);

public static void main(String[] args) {
    String[] bookStrings = { "数据结构", "c语言", "操作系统", "英语" };     
    String book;
    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");
        try {
            int command = inputCommand();
            switch (command) {
            case 1:
                book = getbookByname(bookStrings);
                System.out.println("book：" + book);
                break;
            case 2:
                book = getBookById(bookStrings);
                System.out.println("book：" + book);
                break;
            case -1:
                System.out.println("命令输入错误，请根据提示输入数字命令！");
                continue;

            default:
                System.out.println("命令输入错误！");
                continue;
            }
            break;
        } catch (Exception e) {
            // TODO: handle exception
            System.out.println(e.getMessage());
            continue;// continue只能在循环里使用，若输入错误则再重新循环指令进行输入
        }
    }

}

// 按名称查找
private static String getbookByname(String[] books) throws Exception {
    System.out.println("请输入图书名称");
    String nameString = inputScanner.next();
    for (int i = 0; i < books.length; i++) {
        if (nameString.equals(books[i]))
            return nameString;
    }
    throw new Exception("图书不存在");
}

// 按序号查找
private static String getBookById(String[] books) throws Exception {
    while (true) {
        System.out.println("请输入图书序号");
        try {
            int index = inputScanner.nextInt();
            if (index == -1) {
                System.out.println("命令行输入错误！请根据提示输入数字命令");
            }
            String bookString=books[index];
            return bookString;

        } catch (ArrayIndexOutOfBoundsException e) {
            // TODO: handle exception
            Exception bookNotExists =new Exception("图书不存在");
            bookNotExists.initCause(e);
            throw bookNotExists;
        }
    }

}

// 获得外键输入的选择
private static int inputCommand() {
    int command;
    try {
        command = inputScanner.nextInt();
        return command;
    } catch (Exception e) {
        // TODO: handle exception
        inputScanner = new Scanner(System.in);
        return -1;
    }
}

}