Java - Convertir las comas en espacios al mostrarlo

public class Test {

    public static void main(String[] args) {

        String a = "hola,que,tal";

        System.out.println(a);

        a = a.replace(',',' ');

        System.out.println(a);

    }

}

package PBase;

import java.io.File;

import java.io.IOException;

import java.util.Scanner;

public class Base {

    public static int cantBase() throws IOException {

        //Variables:

        Scanner leer = new Scanner(new File("Base.txt"));

        int cantReg = 0;

        //Creo el ciclo while:

        while (leer.hasNextLine( )) {

            leer.nextLine( );

            cantReg++;

        }

        leer.close( );

        return cantReg;

    }

    public static void mostrarBase(){

        //Creamos la estructura de la Matriz:  

        System.out.print("Nombre\tPP1\tPP2");

        String a = "Base.txt";

        System.out.println(a);

        a = a.replace(',','\t');

        System.out.println(a);

    }

}

package bases;

import PBase.*;

import java.io.*;

public class PrincipalBase {

    public static void main(String[] args) throws IOException {

        //Variables:

        int B = Base.cantBase();

        //Muestro la variable:

        Base.mostrarBase();

    }

}

String texto;

FileReader fr = new FileReader("Base.txt");

BufferedReader br = new BufferedReader(fr);

while((texto= br.readLine())!=null) {

    System.out.println(texto.replace(',','\t'););

}

br.close();