Do I need this whole class to find out if the fraction is reduced or not?

Do I need this whole class to find out if the fraction is reduced or not?

What I have to do is take 2 random variables for a fraction, 1 to 1000,
and check to see if they are in reduced terms already or not. I do this
1,000 times and keep track of whether it was or wasn't in reduced terms.
Here is the main class
import java.util.*;
public class ratio1 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int nonReducedCount = 0; //counts how many non reduced ratios
there are
for(int i =1; i<=1000; i++){
Random rand = new Random();
int n = rand.nextInt(1000)+1; //random int creation
int m = rand.nextInt(1000)+1;
Ratio ratio = new Ratio(n,m);
if (ratio.getReduceCount() != 0 ){ // if the ratio was not
already fully reduced
nonReducedCount++; // increase the count of non reduced
ratios
}
}
int reducedCount = 1000 - nonReducedCount; //number of times the
ratio was reduced already
double reducedRatio = reducedCount / nonReducedCount; //the ratio
for reduced and not reduced
reducedRatio *= 6;
reducedRatio = Math.sqrt(reducedRatio);
System.out.println("pi is " + reducedRatio);
}
}
And here is the class I am not sure about. All I want from it is to
determine whether or not the fraction is already in simplest form. When I
currently try to run it, it is giving me an error; "Exception in thread
"main" java.lang.StackOverflowError at Ratio.gcd(Ratio.java:67) at
Ratio.gcd(Ratio.java:66)"
public class Ratio{
protected int numerator; // numerator of ratio
protected int denominator; //denominator of ratio
public int reduceCount = 0; //counts how many times the reducer goes
public Ratio(int top, int bottom)
//pre: bottom !=0
//post: constructs a ratio equivalent to top::bottom
{
numerator = top;
denominator = bottom;
reduce();
}
public int getNumerator()
//post: return the numerator of the fraction
{
return numerator;
}
public int getDenominator()
//post: return the denominator of the fraction
{
return denominator;
}
public double getValue()
//post: return the double equivalent of the ratio
{
return (double)numerator/(double)denominator;
}
public int getReduceCount()
//post: returns the reduceCount
{
return reduceCount;
}
public Ratio add(Ratio other)
//pre: other is nonnull
//post: return new fraction--the sum of this and other
{
return new
Ratio(this.numerator*other.denominator+this.denominator*other.numerator,this.denominator*other.denominator);
}
protected void reduce()
//post: numerator and denominator are set so that the greatest common
divisor of the numerator and demoninator is 1
{
int divisor = gcd(numerator, denominator);
if(denominator < 0) divisor = -divisor;
numerator /= divisor;
denominator /= divisor;
reduceCount++;
}
protected static int gcd(int a, int b)
//post: computes the greatest integer value that divides a and b
{
if (a<0) return gcd(-a,b);
if (a==0){
if(b==0) return 1;
else return b;
}
if (b>a) return gcd(b,a);
return gcd(b%a,a);
}
public String toString()
//post:returns a string that represents this fraction.
{
return getNumerator()+"/"+getDenominator();
}
}
Here are the lines of the error in the Ratio class;
if (b>a) return gcd(b,a);
return gcd(b%a,a);
thank you.