萌新小白结合大佬的知识写的，请大佬们多多指教

package zonghexunlian1;

public class Book {     
    String name;//书的名称
    int number;//书的序号
    public Book(String name, int number){
        this.name=name;
        this.number=number;
    }
}

package zonghexunlian1;

public class CaException extends Throwable {//定义的异常类
}

package zonghexunlian1;

public class ErrorNumException extends Throwable {//定义的异常类
}

package zonghexunlian1;

public class NoxhException extends Throwable {//定义的异常类
}

package zonghexunlian1;
import java.util.InputMismatchException;
import java.util.Scanner;

public class Initail {
    public void cha(){
        Initail dy=new Initail();
        Book[] book= new Book[]{
                new Book("高数", 1),
                new Book("数据结构", 2),
                new Book("英语", 3)
        };
        int sr=0;//用来接收输入的数
        String sm=null;//用来接收输入的书名
        Book nsm=null;//用来接收你选择的书名并赋值,因为赋值的循环遍历是book类所以用book定义
        boolean br=false;//定义一个布尔类型的值，用来判断
        int xh=0;//用来接收输入的序号
        while (sr!=1&&sr!=2){
            System.out.println("请输入命令：1-按照书名查找，2-按照序号进行查找");

            try {
                Scanner input=new Scanner(System.in);
                sr=input.nextInt();
                if (sr!=1&&sr!=2){
                    throw new NoxhException();
                }
                if (sr==1){
                    System.out.println("请输入图书名称");
                    sm=input.next();
                    for (Book bl:book){//数组遍历，用来进行循环比较
                        if (bl.name.equals(sm)){
                            br=true;
                            nsm=bl;
                        }
                    }
                    if (br){
                        System.out.println("你选择的书是"+nsm.name);
                    }else {
                        sr=0;
                        throw new CaException();
                    }
                }else if (sr==2){
                    System.out.println("请输入图书序号：");
                    xh=input.nextInt();
                    for (Book bl:book){
                        if (bl.number==xh){
                            br=true;
                            nsm=bl;
                        }
                    }
                    if (br){
                        System.out.println("你要找的书是"+nsm.name);
                    }else {
                        sr=0;
                        throw new ErrorNumException();
                    }
                }
            }catch (InputMismatchException e){
                System.out.println("你输入错误，请按提示输入数字");
            }catch (NoxhException e){
                System.out.println("输入有误请输入1或2");
            }catch (CaException e){
                System.out.println("你输入的图书不存在，请重新输入书名");
            }catch (ErrorNumException e){
                System.out.println("你输入的序号不存在，请重新输入数字");

            }
        }


    }
    public static void main(String[] args) throws NoxhException {
        Initail pao=new Initail();
        pao.cha();
    }
}