java第三季异常——图书查询系统

import java.util.Scanner;

  public class Test {

  public static void main(String[] args) throws Exception {
        String[] bookinf=new String[]{"高数","大学英语","马克思理论","论语","大学"};
        while (true){
            Scanner input=new Scanner(System.in);
            System.out.println("欢迎使用图书查找系统");
            System.out.println("1-按照名称查找图书，2-按照序号查找图书");
            try {
                int rec=input.nextInt();//输入命令
                String s1=input.nextLine();//清除缓存区中残留的空白符
                boolean flag=false;//记录图书是否被找到
                if(rec==1){
                    System.out.println("请输入图书名称：");
                    String name=input.nextLine();
                     for(String book:bookinf){
                        try {
                            if(book.equals(name)) {
                                System.out.println("book:"+name);
                                flag=!flag;//书已找到
                                return;
                            }
                        }
                        catch (Exception e){
                            e.printStackTrace();
                            continue;
                        }

                    }
                    if(!flag) {
                        System.out.println("图书不存在!!!");
                        System.out.println(" ");
                        continue;
                    }
                }
                else  if(rec==2){
                    System.out.println("请输入图书序号：");
                    try {
                        int number=input.nextInt();
                        if(number>4||number<0) {
                            System.out.println("图书不存在!!!");
                            System.out.println(" ");
                            continue;
                        }
                        else {
                            System.out.println("book:"+bookinf[number]);
                            return;
                        }
                    }
                    catch (Exception e){
                        System.out.println("请输入正确的序号!!!");
                        System.out.println(" ");
                        continue;
                    }

                }
                else {
                    System.out.println("命令输入错误，请根据提示输入数字命令!!!");
                    System.out.println(" ");
                    continue;

                }
            }
            catch (Exception e){
                System.out.println("命令输入错误，请根据提示输入数字命令!!!");
                System.out.println(" ");
                continue;
            }

        }

    }

}