How to put images on JPanel one at a time?

Question

Hi, guys. I am trying to put 7 images to a panel one by one,each takes one second so that users can see the process each images being shown on the panel.
But the fact is the system freeze for 7 seconds and then display them all once. Altho the "one image has been dealt" showsin the console every one second.
Thank you
Here is the code :
for (int i=0;i<7 ;i++ )
               try
               thisTile[i] = new tiles(BBV.string,"BlackBack",100,100);
               thisTile.setBounds(x1,y1,27,49);               
               JP1.add(thisTile[i]);                              
               y1=y1+54;
               System.out.println("one image has been dealt");
               Thread.sleep(1000);
               catch (InterruptedException e)
                    System.out.println("this should not be printed");

Answer 1

for example, I want to print "all 7 images has been dealt" after the images have been put on the JPanel, by using swing timer it prints the "all 7 images has been dealt" during/before the images being put. Here is the code example(thisTile is a array of 7 images):
public void showImages()
t = new javax.swing.Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent e) {
               thisTile[j] = new tiles(BBV.string,"BlackBack",100,100);
               thisTile[j].setBounds(x1,y1,27,49);               
               JP1.add(thisTile[j]);
               JP1.validate();
               JP1.repaint();
               y1=y1+54;
               j++;
               if (j==7)
                    t.stop();
          //AI1 gets his tiles
          for (int i=0;i<7 ;i++ )
               t.start();               
          System.out.println("all images has been dealt");
          }