Hi,
I am trying out a bank account program using the corejava package.
I am getting a run-time eception when I create a new account & am unable to trace where the error is.
Plz help. I am giving the code below.
import corejava.Console;/******************************************************************cLASS bANKaCCOUNT REPRESENTING THE RUN-TIME MULTI-USER SYSTEM******************************************************************/public class BankAccount{ /**************************** **DATA OF bANKaCCOUNT CLASS** ****************************/ private static final int MAXACC=10; private static int acc_logged_in; private static int no_acc_created; private static Account[] database; /******************************* **METHODS OF bANKaCCOUNT CLASS** *******************************/ // initialisation block { acc_logged_in=-1; no_acc_created=0; database=new Account[MAXACC]; } private static void createnew() { String str; no_acc_created++; acc_logged_in=no_acc_created; str=Console.readLine("\nEnter your name : "); database[acc_logged_in].SETname(str); database[acc_logged_in].SETbalance(Console.readInt("Enter your initial balance : ")); database[acc_logged_in].SETaccountid((int)(Math.random()*32000)); System.out.println("Your account I.D. is " + database[acc_logged_in].GETaccountid()); System.out.println("Account created successfully...\n\n"); } private static void login() { int i,no; boolean found=false; no=Console.readInt("\nEnter your account I.D. : "); for(i=0;i<no_acc_created;i++) { if(no==database.GETaccountid()) { acc_logged_in=i; found=true; break; } } if(found==true) System.out.println("Logged in successfully as " + database[acc_logged_in].GETname() + "...\n\n"); else System.out.println("Error : The I.D. did not match with any of the accounts !\n\n"); } private static void logoff() { if(acc_logged_in==-1) { System.out.println("\nNo account is currently logged in !\n\n"); } else { acc_logged_in=-1; System.out.println("\nLogged off your account successfully...\n\n"); } } private static int menu() { int choice; System.out.println("\n\t\tBANK-ACCOUNT"); System.out.println("\t\t~~~~~~~~~~~~"); System.out.println(""); System.out.println("\t<1> Create new account"); System.out.println("\t<2> Log in your account"); System.out.println("\t<3> Log off your account"); System.out.println("\t<4> View current status"); System.out.println("\t<5> Deposit an amount"); System.out.println("\t<6> Withdraw an amount"); System.out.println("\t<7> Exit BankAccount.java"); do { choice=Console.readInt("\n\t\tEnter your choice (1 to 7): "); } while(choice<1||choice >7); return choice; } public static void main(String[] args) { int choice; boolean want_to_exit=false; while(want_to_exit==false) { choice=menu(); switch(choice) { case 1: createnew(); break; case 2: login(); break; case 3: logoff(); break; case 4: if(acc_logged_in==-1) { System.out.println("Error : No account is logged in !"); break; } database[acc_logged_in].view(); break; case 5: if(acc_logged_in==-1) { System.out.println("Error : No account is logged in !"); break; } database[acc_logged_in].deposit(); break; case 6: if(acc_logged_in==-1) { System.out.println("Error : No account is logged in !"); break; } database[acc_logged_in].withdraw(); break; case 7: want_to_exit=true; break; } } }}/**********************************************************************cLASS aCCOUNT REPRESENTING EVERY INDIVIDUAL ACCOUNT & ITS DETAILS**********************************************************************/// do not mention public\private when a class does not contain the main() to be executedclass Account{ /************************ **DATA OF aCCOUNT CLASS** ************************/ private String name; private int accountid; private int balance; /*************************** **METHODS OF aCCOUNT CLASS** ***************************/ public Account() { name=""; accountid=-1; balance=0; } public int GETaccountid() { return accountid; } public String GETname() { return name; } public void SETname(String str) { name=str; } public void SETaccountid(int id) { accountid=id; } public void SETbalance(int bal) { balance=bal; } public void view() { System.out.println("\nName : " + name); System.out.println("Balance : " + balance + " Rs.\n\n"); } public void deposit() { int dep=Console.readInt("\nEnter the amount you want to deposit : "); balance+=dep; System.out.println("Amount deposited successfully...\n\n"); } public void withdraw() { int wit=Console.readInt("\nEnter the amount you want to withdraw : "); if(wit<=balance) { balance-=wit; System.out.println("Amount withdrawn successfully...\n\n"); } else { System.out.println("Error : The amount you are attempting to"); System.out.println(" withdraw is greater than your balance !\n\n"); } }}
The exception is encountered after I enter a name.
Exception in thread "main" java.lang.NullPointerException
I tried out initialising each account object but even that doesn't work.
Plz help.
