Again.. 3rd time going with java help because im just that special

Ok, this time I need to get help with the concat method to concatenate a string upon itself.
So say I have this code (please dont tell me my for loop wont initiate if i get it wrong because this is just an example >.>)

String pie = new String("I like pie! "); //pie is good btw :P
for (int i=1;i>=10;i++) {
  //concatenate the string Pie with itself thus adding 'I like pie!' to the string pie 10 times.
}
System.out.print(pie);

How would I make that code in the for loop? what would it look like?

sorry but that didnt work

edit: I knew you could use that method, but i wasnt sure how for strings to be concatenated with themselves

just displayed 'I like pie!'

yeah that worked, but not for my specific program really. Ok what my program does.. or what it should do is takes a number of lines, and makes a star pyramid out of it
example
5 lines is this:

    *
   ***
  *****
 *******
*********

here is my code:

import javax.swing.JOptionPane;

public class starz {

public static void main (String []args)
{
String numtemp = JOptionPane.showInputDialog("Enter a number of lines:");
int lines = Integer.parseInt(numtemp);
String star = new String("*");
for (int count=0;count<=lines;count++) {
for (int spaces=lines-1;spaces>0;spaces--) {
System.out.print(".");
}
for (int starcount=1;starcount<=lines;starcount++) {
System.out.print(star);
star = star.concat(star); //still needs to be fixed
star = star.concat(star); //still needs to be fixed
}
System.out.println();
}
}
}
I have a dot replacing a space to make sure its working, but what it does basically is that it prints 1 star, adds 2 more every time supposedly making the pyramid shape. However, the real end result is an infinite loop :s

I'll try this later. Thanks! For now i gtg