异常捕获提问
package com.imooc;
import java.util.Scanner;
public class test1 {
private static Scanner console=new Scanner(System.in);
public static void main(String[] args) {
// TODO Auto-generated method stub
String[] books = { "C语言", "数据结构", "汇编语言", "高数", "大学语文", "毛概" };
while(true){
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 book;
try{
int command=inputCommand();
switch(command){
case 1:
book=getBookByName(books);
System.out.println("book"+book);
break;
case 2:
book=getBookByNumber(books);
System.out.println("book"+book);
break;
case -1:
System.out.println("命令输入错误！请根据提示输入数字命令！");
continue;
default:
System.out.println("命令输入错误！");
continue;
}
break;
}catch(Exception bne){
System.out.println(bne.getMessage());
}
}
}
private static String getBookByName(String[] books) throws Exception{
System.out.println("输入图书名称：");
String name=console.next();
for(int i=0;i<books.length;i++){
if(name.equals(books[i]))
return books[i];
}
throw new Exception("图书不存在！");
}
private static String getBookByNumber(String[] books) throws Exception{
while(true){
System.out.println("输入图书序号：");
try{
int index=inputCommand();
if(index==-1){
System.out.println("命令输入错误！请根据提示输入数字命令！");
continue;
}
String book=books[index];
return book;
}catch(ArrayIndexOutOfBoundsException e){
Exception bookNotExists=new Exception("图书不存在！");
bookNotExists.initCause(e);
throw bookNotExists;
}
}
}
private static int inputCommand(){
int command;
try{
command=console.nextInt();
return command;
}catch(Exception e){
console=new Scanner(System.in);
return -1;
}
}
}
请问为什么这里面都会用到try catch ，只有我加的下划线方法没有try catch？
