redraw the graph

i want to draw the topology of the network which can display the hierachy  relation, which means that when i click on the vertex( subnet or node) i want it to display the topology in that subnet( if it is a subnet).

so i need to redraw the the graph, when i click the node.

but when i implement the graphClicked method of GraphMouseListener

code like this :
public class TopHierachy {
    static Graph graph;
    VisualizationViewer vv;
    public TopHierachy() {
        super();
        graph = getGraph("I:\\ljt\\workplace\\jungTest\\samples\\datasets\\my.net");
        JFrame jf = new JFrame();
        vv = new VisualizationViewer(new KKLayout(graph), new PluggableRenderer());
        vv.addGraphMouseListener(new MySimpleGraphMouse(vv));
        jf.getContentPane().add(vv);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }
    public static Graph getGraph(String filename) {
        Graph g = null;
        try {
            PajekNetReader pnr = new PajekNetReader();
            g = pnr.load(filename);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return g;
    }
      public static class MySimpleGraphMouse extends SimpleGraphMouse implements GraphMouseListener {

            public MySimpleGraphMouse(VisualizationViewer vv) {
                super(vv);
            }

            public void graphClicked(Vertex v, MouseEvent me) {
                graph = getGraph("I:\\ljt\\workplace\\jungTest\\samples\\datasets\\my2.net");
                graph.removeAllEdges();
                vv.repaint();
            }
            public void graphPressed(Vertex v, MouseEvent me) {
            }

            public void graphReleased(Vertex v, MouseEvent me) {
        }
      }
     
      public static void main(String[] args) {
          TopHierachy t = new TopHierachy();
      }
}

i wonder why the handler wasn't invoke when i click the mouse