image doesnt shows on JLabel when click on next button, using java Swing -

i trying make small program shows pic on jlabel when user click on next button.the problem when click on next button shows nothing.but if resize frame shows pics directory. instead of 1 picture @ time. please excuse english. here code.

import java.awt.*; import javax.swing.*; import java.awt.event.*; import javax.imageio.imageio; import java.io.*; import java.awt.image.bufferedimage;  class test {     public static void main(string args[]) {         frame f = new frame();         f.gui();         f.actions();     } }  class frame {      bufferedimage file;     file img;     imageicon icon;      jlabel image;     jframe frame;     jpanel panel;     string[] path = { "juice.jpg", "gal.jpg", "truck.jpg", "drive.jpg" };      jbutton next = new jbutton("next");     jbutton pre = new jbutton("prevoius");     jtextfield field = new jtextfield(10);      static int num = 0;      public void gui() {          frame = new jframe("pic gallery");         frame.setdefaultcloseoperation(jframe.exit_on_close);         frame.setvisible(true);         flowlayout flow = new flowlayout();         frame.setlayout(flow);         panel = new jpanel();         panel.setlayout(new boxlayout(panel, boxlayout.line_axis));         panel.add(next);         panel.add(pre);         panel.add(field);          jlabel piclabel = new jlabel();          frame.getcontentpane().add(panel);     }      void actions() {          next.addactionlistener(new actionlistener() {             public void actionperformed(actionevent e) {                 img = new file(path[num]);                 system.out.println(num);                 try {                     file = imageio.read(img);                     icon = new imageicon(file);                     image = new jlabel("", icon, jlabel.center);                      image.setvisible(true);                     frame.getcontentpane().add(image);                  } catch (ioexception g) {                  }                 if (num < path.length - 1) {                     num++;                     field.settext(num + "");                  } else {                     num = 0;                  }             }         });     } } 

add frame.revalidate() , frame.repaint() after frame.getcontentpane().add(image);

swing lazy when comes performing updates layout hierarchy, thing, imagine adding few dozen components , having entire component hierarchy been updated each one.

so, instead, need update container manually when you've made changes

added suggested . shows next image on frame along prevous image. wants 1 image @ time

then remove first image, or better yet, instead of creating new jlabel each time, create single jlabel , change it's icon property, should invalidate container automatically