Hi guys,
i've developed a java application that give me this error in run-time

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
       at Riga.main(Riga.java:51)

Can you help me to solve it?Thanks...

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;
public class Riga{
    private static String fileName = "Dato2.txt";
    private String geneid=null;
    private double[] values=new double[5];
    private static int row=0;
    private static int numberOfNumericColumns=0;
    private static int col=0;

    public Riga(String idGene,double[] x ) {
   this.geneid=idGene;
   this.values=x;
    }
    public String getgeneid(){
        return this.geneid;
    }
    public void setgeneid(String idGene){
        this.geneid=idGene;
    }
    public double[] getvalues(){
        return this.values;
    }
    public void setvalues(double[] x){
        this.values=x;
    }
    public void id(){
        System.out.println("La linea è"+geneid+values);
    }

    public static void main(String[] args) throws IOException {
        FileReader reader=new FileReader(fileName);
        BufferedReader br = new BufferedReader(reader);
        ArrayList <Riga> rows = new ArrayList <Riga>();
        String line = null;
        double[] y=new double[(numberOfNumericColumns)];
        while ((line = br.readLine()) != null) {
            line = line.replace (',', '.');
            row++;

     StringTokenizer st = new StringTokenizer(line);
     numberOfNumericColumns = (st.countTokens()-1);
     col=(numberOfNumericColumns+1);
     String x=st.nextToken();
     for (int i=0;i<numberOfNumericColumns;i++){
            y[i]=Double.parseDouble(st.nextToken());
     }
     Riga z=new Riga(x,y);
     rows.add(z);
   }
       
        for(int i=0;i<row;i++)
            rows.get(i).id();
    }
}