Stringtokenizer needs to ignore Negative numbers and terminate when 0 is enter

[Katherine692008]

How do I get this to ignore negative number and terminate when the number 0 is entered?
Please HELP

public void productTokenizer()throws IOException
{
System.out.println("Enter numbers to accumlulate their total.");//Prompt user to enter data
//System.out.println("Zero and all negative numbers will Exit the Program:");

double sum = 0; int num = 0;

BufferedReader br = new BufferedReader(
new InputStreamReader(System.in));
String input = br.readLine();

StringTokenizer tokenizer = new StringTokenizer(input);


while (tokenizer.hasMoreTokens())
{



String token = tokenizer.nextToken();

double x = Double.parseDouble(token);
sum = sum + x;
num++;
}

System.out.println("The sum is: " + sum);

}
}

[Samudricka]

i think it can be done after converting into double please ckeck with an if condition if(x>0) then i think you can access only positive numbers