InputException.java

package com.imooc.test;

public class InputException extends Exception {

???? public InputException() {

???????? super();

???????? System.out.println("命令輸入錯誤！請根據提示輸入數字命令！");

???? }

???? public InputException(String message) {

???????? super(message);

???????? System.out.println(message);

???? }

}

BookBorrow.java

package com.imooc.test;

import java.util.Arrays;

import java.util.InputMismatchException;

import java.util.Scanner;

public class BookBorrow {

???? private static String[] books = { "高數", "積分變換", "線性代數", "馬克思哲學" };

????

???? public static void main(String[] args) {

???????? // TODO Auto-generated method stub

???????? BookBorrow bkb = new BookBorrow();

???????? bkb.borrow();

???? }

????

???? public void borrowByName(Scanner input) throws InputException {

???????? System.out.println("輸入圖書名稱：");

???????? String name = input.next();

???????? if (-1 == Arrays.binarySearch(books, name)) {

???????? ???? System.out.println("圖書不存在！");

? ? ? ? ? ? ?throw new InputException();

???????? } else {

???????????? System.out.println("book: " + name);

???????? }

???? }

????

???? public void borrowByNumber(Scanner input) throws InputException {

???????? System.out.println("輸入圖書序號：");

???????? int num = input.nextInt();

???????? if (num < 1 || num > books.length) {

???????? ???? System.out.println("圖書不存在！");

? ? ? ? ? ? ? throw new InputException();

???????? } else {

???????? ???? System.out.println("book: " + books[num - 1]);

???????? }

???? }

????

???? public void borrow() {

???????? Scanner input = new Scanner(System.in);

???????? System.out.println("輸入命令：1-按照名稱查找圖書；2-按照序號查找圖書");

???????? try {

???????????? switch (input.nextInt()) {

???????????????? case 1:

???????????????? ???? borrowByName(input);

???????????????? ???? break;

???????????????? case 2:

???????????????????? borrowByNumber(input);

???????????????????? break;

???????????????? default:

???????????????? ???? System.out.println("命令輸入錯誤！請根據提示輸入數字命令！");

???????????????????? borrow();

???????????????????? break;

???????????? }

???????? } catch(InputException e) {

????????

???????? }catch (InputMismatchException e) {

???????????? System.out.println("命令輸入錯誤！請根據提示輸入數字命令！");

???????? } catch (Exception e) {

???????????? // TODO: handle exception

???????????? e.printStackTrace();

???????? } finally {

???????????? borrow();

???????????? input.close();

???????? }

???? }

}