java - Request to a Threadpool from a thread

Question

I need to make an application that generates a list containing the following characters: H,A,O,*,#,@. The last two are control characters. The "#" makes the list divide in two (like a tree) and each sublist have to continue filling until the "@" appears, which indicates the list is finish. This process continues until all of the sublists have the "@" or the lenght of all the sublists together are 10000.

Then I have to iterate through the list using threads, and for each of the characters paint a different image in a frame. When I find a "#", the thread have to start two other threads to iterate throught the next two sublists and it have to terminate.

I am getting stuck in the part when I have to start the new threads and finish the first one. Googling I found a way to do this, but I feel that is a bad way to do it. So my question is: Is there another way to make this?

public class PainterThread implements Runnable {


public PainterThread(Iterator pIterator, ExecutorService pPool, PaintingPanel pPanel) {
    _iteratorList = pIterator;  //the Iterator of the list
    _Pool = pPool;          //I pass the ThreadPool as a parameter in order to make the request to create new threads
    _PanelToPaint = pPanel;// The Panel which going to paint the images
}

//Methods
@Override
public void run() {
    while (_iteratorList.hasNext()) {
        Node actualNode = (Node) _iteratorList.next();
        switch (actualNode.getControlSign()) {
            case "H":
                _PanelToPaint.addShapes(new Square(actualNode.getPositionX(), actualNode.getPositionY(), actualNode.getSize()));
                _PanelToPaint.repaint();
                break;
            case "A":
                _PanelToPaint.addShapes(new Triangle(actualNode.getPositionX(), actualNode.getPositionY(), actualNode.getSize()));
                _PanelToPaint.repaint();
                break;
            case "O":
                _PanelToPaint.addShapes(new Circle(actualNode.getPositionX(), actualNode.getPositionY(), actualNode.getSize()));
                _PanelToPaint.repaint();
                break;
            case "*":
                _PanelToPaint.addShapes(new Asterisk(actualNode.getPositionX(), actualNode.getPositionY(), actualNode.getSize()));
                _PanelToPaint.repaint();
                break;
            case "#":
                LinkedList actualList = (LinkedList) _iteratorList.next();
                _Pool.submit(new PainterThread(actualList.iterator(), _Pool,_PanelToPaint)); //Here is my question. Is there another way to make this?
                if (_iteratorList.hasNext()) {
                    actualList = (LinkedList) _iteratorList.next();
                    _Pool.submit(new PainterThread(actualList.iterator(), _Pool, _PanelToPaint));
                }
                break;
            case "@":
                break;
        }
    }
}

public void setIterator(Iterator pNewIterator) {
    _iteratorList = pNewIterator;
}
//Atributes
private Iterator _iteratorList;
private ExecutorService _Pool;
private PaintingPanel _PanelToPaint;

}