NullPointerException

[Emile Ghazzawi]

Hi,
I am creating a project as part of a University Assignment and all was well until i encountered a dreaded NullPointerException! I have tried all i can to work a way around it but just can't seem to suss it out. It has been causing me endless hours of frustration! If anyone could help me out then it would be HUGELY appreciated! I have included my code below and the error seems to be occuring on line 210 which reads:
if (stockCode[itemNum].equals(searchItem))
My Code
-------

import java.io.*;
public class StockControl_Test
{
private static final int maxItems = 20;
private static String[] stockCode = new String[maxItems];
private static String[] stockDesc = new String[maxItems];
private static int[] currentLevel = new int[maxItems];
private static int[] reorderLevel = new int[maxItems];
private static float[] price = new float[maxItems];
private static int numItems = 0;

public static void main(String[] args)
throws IOException
{
String stringOption;
char charOption;
int numOrders = 0, totalValue = 0;
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
readData();
displayData();
do
{
try{
Thread.sleep(1000);
displayMenu();
} catch (InterruptedException e) {}
stringOption = input.readLine();
charOption = stringOption.charAt(0);
switch (charOption)
{
case '1': extendStock();
  break;
case '2':acceptStock();
break;
case '3':totalValue = processOrder(totalValue);
numOrders++;
break;
case '4':displayReorderList();
break;
case '5':displayItem();
break;
case '6':break;
default:System.out.println("\n\nInvalid Selection - Please Try Again\n\n");
try{
Thread.sleep(1000);
} catch (InterruptedException e) {}
break;
}
}while (charOption != '6');
}
public static void extendStock()
throws IOException
{
if (numItems == maxItems) {
System.out.println("\n\nMaximum Stock Level Reached\n\n");
try{
Thread.sleep(1000);
} catch (InterruptedException e) {}
return;
}
String stringOption, textCurrent, textReorder, textPrice;
char charOption = ' ';
numItems++;
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
System.out.println("\n\nPlease Enter Stock Code:");
stockCode[numItems] = input.readLine();
System.out.println("\n\nPlease Enter Stock Description:");
stockDesc[numItems] = input.readLine();
System.out.println("\n\nPlease Enter Current Level:");
textCurrent = input.readLine();
currentLevel[numItems] = Integer.parseInt(textCurrent);
System.out.println("\n\nPlease Enter Reorder Level:");
textReorder = input.readLine();
reorderLevel[numItems] = Integer.parseInt(textReorder);
System.out.println("\n\nPlease Enter Price:");
textPrice = input.readLine();
price[numItems] = Float.parseFloat(textPrice);
if (numItems < maxItems) {
System.out.println("\n\nWould You Like To Enter Another Item? - Y/N");
stringOption = input.readLine();
charOption = stringOption.charAt(0);
if ((charOption == 'Y') || (charOption == 'y')) {
extendStock();
}
}
System.out.println("\n\n");
return;
}
public static void acceptStock()
{

}
public static int processOrder(int totalValue)
{

return totalValue;
}
public static void displayReorderList()
{
System.out.println("\n\nStock Code\tCurrent Level\tReorder Level\tPrice");
System.out.println("----------\t-------------\t-------------\t-----");
for (int count=1; count <= numItems; count++)
{
if (currentLevel[count] <= reorderLevel[count])
{
System.out.println(stockCode[count] + "\t\t\t" + currentLevel[count] + "\t\t" + reorderLevel[count] + "\t" + price[count]);
}
}
}
public static void displayItem()
{
try{
int location = findItem();
System.out.println("\n\nCurrent Level\t\tReorder Level");
System.out.println("-------------\t\t-------------");
System.out.println(currentLevel[location] + "\t\t" + reorderLevel[location]);
} catch (IOException e) {}
}
public static void readData()
throws IOException
{
File file = new File("stock.txt");
if(file.exists())
{
int count=0;
String txtCurrentLevel, txtReorderLevel, txtPrice, currentData;
BufferedReader input = new BufferedReader(new FileReader("stock.txt"));
do
{
  count++;
  stockCode[count] = input.readLine();
  stockDesc[count] = input.readLine();
  txtCurrentLevel = input.readLine();
  currentLevel[count] = Integer.parseInt(txtCurrentLevel);
  txtReorderLevel = input.readLine();
  reorderLevel[count] = Integer.parseInt(txtReorderLevel);
  txtPrice = input.readLine();
  price[count] = Float.parseFloat(txtPrice);
}while (input.ready());
input.close();
numItems = count;
if (count <= 0) {
System.out.println("File Empty!");
}
}
else
{
System.out.println("\n\n\t\tERROR - Stock File Could Not Be Found\n\n");
try{
Thread.sleep(1000);
} catch (InterruptedException e) {}
}
}
public static void displayMenu()
{
System.out.println("\n\n\t\tWelcome To The Stock Control System");
System.out.println("\t\t------- -- --- ----- ------- ------\n");
System.out.println("Please Select An Option From The List Below:\n\n");
System.out.println("(1)  -  Initialise/Extend Stock");
System.out.println("(2)  -  Process Stock Delivery");
System.out.println("(3)  -  Process Sale");
System.out.println("(4)  -  Items At/Below Re-Order Level");
System.out.println("(5)  -  Items Current/Re-Order Level");
System.out.println("(6)  -  Quit\n");
System.out.println("Option Number:");
}
public static int findItem()
throws IOException
{
BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
String searchItem;
System.out.println("\nPlease Enter Stock Code:");
searchItem = input.readLine();
for (int itemNum = 0; itemNum < stockCode.length; itemNum++)
{
if (stockCode[itemNum].equals(searchItem))
{
return itemNum;
}
}
return -1;
}
public static void displayData()
{
System.out.println("Stock Code\tStock Desc.\tCurrent Level\tReorder Level\tPrice");
System.out.println("----------\t-----------\t-------------\t-------------\t-----");
for (int count=1; count <= numItems; count++)
{
System.out.println(stockCode[count] + "\t\t" + stockDesc[count] + "\t\t" + currentLevel[count] + "\t\t" + reorderLevel[count] + "\t" + price[count]);
}
}
}

[JAM -->Edited to use [CODE] and [/CODE] tags]
[ April 19, 2004: Message edited by: Joel McNary ]

[Michael Dunn]

It looks like your problem is in readData()
int count=0;
...
...
do
{
count++;//<---------------count is now 1, meaning stockCode[0] is null
stockCode[count] = input.readLine();
move the count++ to the end of the do/while block

[Emile Ghazzawi]

Hi again,
Solved it by changing the problamatic line 210 to
CODE] if (stockCode[itemNum]!=null && stockCode[itemNum].equalsIgnoreCase(searchItem))[ [/CODE]
Also implemented your idea, much more sensible that putting it before !
Thanks for your help, i sure i'll be back asking for more very shortly!
Thanks again,
Emile

[Mike Gershman]

I can't speak for your teacher, but where I went to school we'd lose points for not indenting. It's hard to follow your logic otherwise.

[Joel McNary]

It's not that the code wasn't indented; it's that the [CODE] and [/CODE] tags were not used; thus, the indenting was not preserved. I edited the post to include them this time....