运行一直有错误，求大家帮我看看，我实在找不出来问题= =

import java.io.*;
public class AccountDemo
{
public static void main(String args[])
{
CheckingAccount a1=new CheckingAccount();
System.out.println("请开账户");
int accNum2,num;
double balance;
String aname,a,b;
try
{
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.print("请输入开户人的姓名：");
aname=in.readLine();
System.out.print("请输入开户人的帐号：");
a=in.readLine();
accNum1=Integer.valueOf(a).intValue();

        System.out.println("======服务=======");
        System.out.println("1 取钱   2 存钱   3 查询  4结束");
        b=in.readLine();
        num=Integer.valueOf(b).intValue();
        System.out.println("请输入您所需要的操作!");
    }
    catch(Exception e)
    {
        System.out.println("您输入的数据有误！");
        return;
    }
    Account.name=aname;
    Account.accNum=accNum1;
    while(num!=4)
    {
        if(num==1)
        {
            a1.withdraw();
            try
            {
                BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
                System.out.println("======服务=======");
                System.out.println("1 取钱   2 存钱   3 查询  4结束");
                b=in.readLine();
                num=Integer.valueOf(b).intValue();
            }
            catch(Exception e)
            {
                System.out.println("您输入的数据有误！");
                return;
            }
        }
        if(num==2)
        {
            a1.deposit();
            try
            {
                BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
                System.out.println("======服务=======");
                System.out.println("1 取钱   2 存钱   3 查询  4结束");
                b=in.readLine();
                num=Integer.valueOf(b).intValue();
            }
            catch(Exception e)
            {
                System.out.println("您输入的数据有误！");
                return;
            }

        }
        if(num==3)
        {
            a1.dispaly();
            try
            {
                BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
                System.out.println("======服务=======");
                System.out.println("1 取钱   2 存钱   3 查询  4结束");
                b=in.readLine();
                num=Integer.valueOf(b).intValue();
            }
            catch(Exception e)
            {
                System.out.println("您输入的数据有误！");
                return;
            }
        }
    }
}

}

class CheckingAccount extends Account
{
public static double overdraft=0;
public static double limit=500;
public static double withdraw()
{
double q1;
String q;
try
{
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.print("请输入取款额：");
q=in.readLine();
q1=Double.valueOf(q).doubleValue();
}
catch(Exception e)
{
System.out.println("您输入的数据有误！");
return balance;
}
if(q1<=balance)
{
balance=balance-q1;
System.out.println("操作成功！");
return balance;
}
else if(q1>balance+limit-overdraft)
{
System.out.println("透支达到上限，拒绝透支！");
return balance;
}
else if(balance {
balance=0;
overdraft=q1-balance+overdraft;
System.out.println("操作成功！已透支！");
return overdraft;
}
}
public static double deposit()
{
double s;
String d;
try
{
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
System.out.print("请输入存款额：");
d=in.readLine();
s=Double.valueOf(d).doubleValue();
}
catch(Exception e)
{
System.out.println("您输入的数据有误！");
return balance;
}
if(overdraft=0)
{
balance=s+balance;
System.out.println("操作成功！");
return balance;
}
if(overdraft>=s)
{
overdraft=overdraft-s;
System.out.println("操作成功！");
return overdraft;
}
if(overdraft<s)
{
overdraft=0;
balance=s-overdraft+balance;
return balance;
}
}
}

class Account
{
public static String name;
public static int accNum;
public static double balance;

public Account(double balance)
{
    this.balance=balance;
}

public static double withdraw()
{
    double r;
    String c;
    try
    {
        BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
        System.out.print("请输入取款额：");
        c=in.readLine();
        r=Double.valueOf(c).doubleValue();
    }
    catch(Exception e)
    {
        System.out.println("您输入的数据有误！");
        return balance;
    }
    if(r<balance)
    {
        balance=balance-r;
        System.out.println("操作成功！");
        return balance;
    }
    else
        System.out.println("余额不足！");
        return balance;

}

public static double deposit()
{
    double s;
    String d;
    try
    {
        BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
        System.out.print("请输入存款额：");
        d=in.readLine();
        s=Double.valueOf(d).doubleValue();
    }
    catch(Exception e)
    {
        System.out.println("您输入的数据有误！");
        return balance;
    }
        balance=s+balance;
        System.out.println("操作成功！");
        return balance;
}

public static void dispaly()
{
    System.out.println("姓名："+name);
    System.out.println("帐号："+accNum);
    System.out.println("余额："+balance);

}

}

报什么错？

可以先自己断点 debug 调试下

自己看看错误提示，如果还解决不了就把报错贴出来看看

不提供报错信息怎么整？估计是你的Integer转换超整数限了

吧错误信息粘出来，你可以自己debug一下

把报错信息粘一下吧，这样看不出问题在哪