directJava [[
import drjava.util.GUIUtil;

import javax.swing.*;

public class PFE {
  public static void main(String[] args) {
    JFrame frame = new JFrame("A Java window made by TinyBrain");
    frame.setSize(400, 400);
    GUIUtil.centerOnScreen(frame);
    GUIUtil.showMainFrame(frame);
  }
}
]]()