Catching an exception (help)!!!

Question

Hi everyone, the problem i have is when the user enters a number that is out of bounds (higher or lower than the excepted values it should prompt the program to write to the screen "out of range, try again" or something along those lines.
However, it instead just prints "error - program terminated" which is the message that should be printed when there is a different problem within the program.
Can anyone help me get the program to print the correct messages, you can see what i mean from the code:
import java.io.*;
import java.util.ArrayList;
public class FlatCost { 
    ArrayList floors = new ArrayList();
    public FlatCost(String filename)  {   
        try    {     
            readDataFromFile(filename);
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
            int floor;
            int rooms;     
            String another = "y";     
            while(another.equalsIgnoreCase("y"))      {
                System.out.print("\nEnter floor number (0 for ground): ");
                floor = Integer.parseInt(in.readLine());      
                if(floor < 0 || floor > floors.size())        {
                System.out.println("floor out of range, try again");       
            else        {
                System.out.print("\nEnter no. rooms: ");
                rooms = Integer.parseInt(in.readLine());         
                if(rooms < 0 || rooms > ((String[])floors.get(floor)).length)          {
                    System.out.println("rooms out of range, try again");         
                else          {
                    System.out.println("\nThe cost of a "+rooms+"-room flat on floor "+floor+" is "+                                  
                    ((String[])floors.get(floor))[rooms+1]+" per month");
                    System.out.print("\nAnother? (y/n): ");
                    another = in.readLine();         
        catch(Exception e){
            System.out.println("error - program terminated");
public void readDataFromFile(String filename)throws Exception {
BufferedReader br = new BufferedReader(new FileReader(filename));
String line = "";
while((line = br.readLine()) != null)
floors.add(line.split(" "));
br.close();
public static void main(String args[])throws IOException{
new FlatCost(args[0]);
}any help is appreciated
thanks
Sarah x

Answer 1

I barely know where to begin.
Start by printing out the stack trace when you catch an exception. That'll give you more information than the message you're printing out. You know the program is terminating - you need to know why.
You're writing in a VERY procedural style. There's little or nothing object-oriented about what you're doing.
You've got a bunch of stuff in that constructor that really doesn't belong there. You shouldn't have code to continuously ask a client for a floor and room number in a constructor. That really belongs in an application that drives the object, like the main method that you wrote.
Your FlatCost can read in a file that contains floor/room/price information, but if I were writing the application I'd read it in and store it in the ArrayList as you've done. Then I'd have a getCost() method that would take floor and room count as parameters and return the total cost.
Learning how to program is learning how to debug. I'd rewrite things a little bit and put System.out.println() statements into the code to narrow down exactly where the error was occurring and why. It won't take you long to figure it out. You don't even need a fancy debugger or IDE.