模拟借书系统 第一次写请大神们多多指点

//Main 方法  

package www.baidu.com;
import java.util.*;
public class Main {

    /**
     * @param args
     * @throws NoBookException 
     */
//命令输入错误异常，
    public void test1() throws WrongException{
        throw new WrongException("命令输入错误！请根据提示输入数字命令");
    }
// 图书不存在异常
    public void test2() throws NoBookException {
        throw new NoBookException("图书不存在");
    }
    public static void main(String[] args)  {
        // TODO Auto-generated method stub

        show [] V = new show[100];
        V [0] = new show ("高数");
        V [1] = new show ("数据结构");
        V [2] = new show ("西游记");
        V [3] = new show ("水浒传");
        V [4] = new show ("三国演义");
        V [5] = new show ("红楼梦");
        V [6] = new show ("英语");
        V [7] = new show ("JAVA");
        V [8] = new show ("语言编译");
        V [9] = new show ("三毛流浪记");
////        System.out.println(V[2].getName());
        do{
        Scanner input = new Scanner(System.in);
        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");
        String a = input.next();
        if(a.equals("1")){
            boolean flag=false;
            System.out.println("输入图书名称");
            String bookname = input.next();
            for(int i = 0; i < V.length;i++){
//              System.out.println(V[i].getName());
                if (bookname.equals(V[i].getName())){
                    System.out.println("book："+bookname);
                    flag=true;
                    break;
                }
            }
            if(flag==false){
                Main input2 = new Main ();
                try {
                    input2.test2();
                } catch (NoBookException e) {
                    // TODO Auto-generated catch block
                    System.out.println(e.getMessage());
                }
            }
        }else if(a.equals("2")) {
            boolean flage=false;
            System.out.println("输入图书序号");
            String b = input.next();
//          System.out.println(V[b].getName());
                for(int i = 0; i < V.length;i++){
                    if(b.equals(i+1)){
                        System.out.println(V[i].getName());
                        flage = true;
                        break;
                    }
                }
                if(flage==false){
                    Main input3 = new Main();
                    try {
                        input3.test2();
                    }catch (NoBookException e) {
                        // TODO Auto-generated catch block
                        System.out.println(e.getMessage());
                    }
                }
            }else{
            Main input2 = new Main();
            try {
                input2.test1();
            } catch (WrongException e) {
                // TODO Auto-generated catch block
                System.out.println(e.getMessage());
            }
            continue;
            }
        }while (true);
    }

}

//show.java 这个类是习惯写成的set和get 
package www.baidu.com;

public class show{
    private String  name;
    public show(){

    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public show(String name) {
        // TODO Auto-generated constructor stub
        setName(name);
    }

}

//NoBookException.java  继承了Exception
package www.baidu.com;

public class NoBookException extends Exception{
    public NoBookException(){

    }
    public NoBookException (String str){
        super(str);
    }
}

//WrongException.java 继承了Exception，
package www.baidu.com;

public class WrongException  extends Exception{
    public WrongException (){

    }
    public WrongException (String str){
        super(str);
    }
}