復制粘貼格式化，我還沒調試，如果有錯誤可以回復分享一下。

package com.booksearch;

import java.util.*;

public class BookSearch {

public static void main(String[] args) {

String[] books = { "數據結構", "高數", "論語" };

boolean flag = true;

while (flag) {

try {

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

Scanner input = new Scanner(System.in);

int cmdnum = input.nextInt();

if (cmdnum == 1) {

System.out.println("輸入圖書名稱：");

String name = input.next();

for (String book : books) {

if (book.equals(name)) {

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

flag = false;

break;

}

}

if (flag) {

System.out.println("圖書不存在");

continue;

}

} else if (cmdnum == 2) {

System.out.println("輸入圖書序號：");

int id = input.nextInt();

for (int i = 0; i < books.length; i++) {

if (id > 0 && id <= books.length) {

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

flag = false;

break;

}

}

if (flag) {

System.out.println("圖書不存在");

continue;

}

}

} catch (Exception e) {

System.out.println("命令輸入錯誤！請輸入數字命令！");

continue;

}

}

}

}