Thread: Resource leakage problem

Hi guys

Getting a strange error when I build this program using the Eclipse IDE
(Using Java version 8). I do not understand why I am getting an error -
the book I use does not even explain about this. I might add this is the first
program I have written using the Scanner utility.

The error is:

java Error at line 7: Resource Leak: 'input' is never closed

I have posed all the code, as I have no idea where the problem is.
Thanks very much for any help!

Wishes Ada xx

import java.util.Scanner;
 
public class MainClass
{
	public static void main(String[] args)
	{
		Scanner input = new Scanner(System.in);
 
		int num1 = 0; // first number
		int num2 = 0; // second number
		int num3 = 0; // third number
		int num4 = 0; // fourth number
		int num5 = 0; // fifth number
		int positive = 0; // number of positive inputs
		int negative = 0; // number of negative inputs
		int zero = 0; // number of zero inputs
 
		System.out.print("Enter an integer: ");
		num1 = input.nextInt();
		System.out.print("Enter an integer: ");
		num2 = input.nextInt();
		System.out.print("Enter an integer: ");
		num3 = input.nextInt();
		System.out.print("Enter an integer: ");
		num4 = input.nextInt();
		System.out.print("Enter an integer: ");
		num5 = input.nextInt();
		input.close();
 
		// count number of positive numbers
		if (num1 > 0) positive = positive + 1;
		if (num2 > 0) positive = positive + 1;
		if (num3 > 0) positive = positive + 1;
		if (num4 > 0) positive = positive + 1;
		if (num5 > 0) positive = positive + 1;
 
		// count number of negative numbers
		if (num1 < 0) negative = negative + 1;
		if (num2 < 0) negative = negative + 1;
		if (num3 < 0) negative = negative + 1;
		if (num4 < 0) negative = negative + 1;
		if (num5 < 0) negative = negative + 1;
 
		// count number of zero values
		if (num1 == 0) zero = zero + 1;
		if (num2 == 0) zero = zero + 1;
		if (num3 == 0) zero = zero + 1;
		if (num4 == 0) zero = zero + 1;
		if (num5 == 0) zero = zero + 1;
 
		System.out.println("Positives: " + positive
				+ "\nNegatives: " + negative
				+ "Zero-based: " + zero);
	}
}

Originally Posted by GregBrannon

It's a warning. You can ignore it if you'd like, but it's the IDE trying to help.

I see you've closed input on line 28, so you shouldn't be getting the warning with the code you've posted. If you still are, sometimes (rarely), Eclipse isn't always displaying issues with the latest version of the source code. Try rebuilding, closing/reopening, running, etc. to move Eclipse into the present.

I'm not sure that it has anything to do with the behavior you're experiencing, but Eclipse Kepler SR 2 has a patch for Java 8. There are specific instructions how to install the patch that you can find by searching.

Thank you Greg! All it working now - the problem was indeed the fact Eclipse did not check that I had added the close() function
at that line. After I did a re-build and debugged again, the warming had vanished - the code works fine. Coming from C#, I used to
do:

int num1 = int.Parse(System.Console.ReadLine());

but never had to close input after that statement. I know Java is totally different in this aspect,
but to be honest that code in C# was too long winded for a simple input. Loving Java's shorter style!
Thanks again!

Wishes Ada xx

Thank you for the additional information Cornix - I will keep than in mind for future
applications.

Wishes Ada xx