这个程序运行报错是哪里出问题了？？？

Question

import java.util.Arrays;

import java.util.Date;

import java.util.Scanner;

import java.lang.reflect.Array;

import java.text.ParseException;

import java.text.SimpleDateFormat;

public class bookSet{

public static void main(String[] args){

String[] name=new String[5];

String[] state=new String[5];

String[] date=new String[5];

//int[] count=new int[9];

Scanner input=new Scanner(System.in);

SimpleDateFormat sdf=new SimpleDateFormat("yyyy-mm-dd");

public void startMenu(){

System.out.println("@@@@@@@@@@@@");

System.out.println("welcom to booksystem!");

System.out.println("1,add book");

System.out.println("2,look book");

System.out.println("3,delete book");

System.out.println("4,lend book");

System.out.println("5,return book");

System.out.println("6,exit system");

System.out.println("@@@@@@@@@@@@");

System.out.println("please to select");

int select=input.nextInt();

switch(select){

case 1:

System.out.println("add new book");

System.out.println("@@@@@@@@@@@@");

Add();

startMenu();

break;

case 2:

System.out .println("look the book");

System.out.println("@@@@@@@@@@@@");

Look();

startMenu();

break;

case 3:

System.out.println("delet the book");

System.out.println("@@@@@@@@@@@@");

Delet();

startMenu();

break;

case 4:

System.out.println("lend the book");

System.out.println("@@@@@@@@@@@@");

Lend();

startMenu();

break;

case 5:

System.out.println("return the book");

System.out.println("@@@@@@@@@@@@");

Return();

startMenu();

break;

case 6:

System.out.println("exit the system");

break;

}

}

}

public void Look(){

System.out.println("num"+"\tstate"+"\tname"+"\tlenddate");

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

if(this.name[i]==null){

break;

}

System.out.println((i+1)+"\t"+this.state[i]+"\t"+this.name[i]+"\t"+this.date[i]);

}

}

/*public void Add(){

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

if(name[i]==null){

System.out.println("please to input information");

name[i]=in.next();

state[i]="1";

System.out.println("yes or no");

String a=in.next();

if(a.equals("n")){

System.out.println("go back no add");

break;

}

}

}

}*/

public void Delet(){

System.out.println("input delet bookname");

String bookname=input.next();

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

if(name[i]!=null&&name[i].equals(bookname)&&state[i].equals("1")){

int j=i;

while(name[j=+1]!=null){

name[j]=name[j+1];

state[j]=state[j+1];

date[j]=date[j+1];

j++;

}

name[j]=null;

state[j]=null;

date[j]=null;

System.out.println("delet ok");

break;

}else if(name[i].equals(bookname)&&state[i].equals("0")){

System.out.println("lend out can't delet");

break;

}

}

}

public void Add(){

System.out.println("input new bookname");

String bookname=input.next();

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

if(name[i]==null){

System.out.println("please to input newbook");

name[i]=input.next();

state[i]="1";

System.out.println("to go on 'y' or 'n'");

String y=input.next();

if(y.equals("n")){

System.out.println("break to add");

break;

}

}

}

}

public void Lend(){

System.out.println("you want to lendname");

String bookname=input.next();

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

if(name[i].equals(bookname)&&state[i].equals("1")){

System.out.println("can lend out");

state[i]="0";

System.out.println("the lend date is:");

date[i]=input.next();

break;

}

else if(name[i].equals(bookname)&&state[i].equals("0")){

System.out.println("the book is lendout can't lend again");

break;

}

else if(name[i]==null){

System.out.println("no this book");

}

}

}

public void Return(){

System.out.println("the return bookname");

String rname=input.next();

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

try{

if(name[i].equals(rname)){

state[i]="1";

Date d=sdf.parse(date[i]);

System.out.println("the return date");

String q=input.next();

Date d1=sdf.parse(q);

long price=((d1.getTime()-d.getTime())/(24*60*60*1000));

System.out.println("the 1 day's price:");

int danjia=input.nextInt();

int price1=(int)(danjia*price);

System.out.println("return success"+"the money is"+price1);

break;

}

}catch(ParseException ex){

}

}

}

}

Answer 1

这么多代码，估计没人有那么多时间一行行的看代码，你应该把错误提示贴出来。

Answer 2

最好帖错误的提示。