A default loading screen is displayed when an applet is being loaded in the web page. You can display a customized splash screen by specifying the following parameters when you deploy the applet:
image - the image to be displayed in the splash screenboxbgcolor - the background color of the area in which the applet will be displayedboxborder - whether the applet should have a border; defaults to truecenterimage - the position of the image; defaults to falseThe splash screen can display a static image or an animated gif.
The code snippet from 
AppletPage.html
<script src="https://www.java.com/js/deployJava.js"></script>
<script> 
  var attributes = {code:'SwingSet2Applet.class',
      archive:'SwingSet2.jar', width:695, height:525} ; 
    <!-- customize splash screen display options -->
  var parameters = {jnlp_href: 'SwingSet2.jnlp', 
                    image: 'dukeanimated.gif', 
                    boxbgcolor: 'cyan', 
                    boxborder: 'true', 
                    centerimage: 'true'   
                    }; 
  deployJava.runApplet(attributes, parameters, '1.6'); 
</script>
Open 
AppletPage.html
See the Displaying a Customized Loading Progress Indicator topic for information about displaying a customized loading progress indicator when the applet's resources are being downloaded.
Download source code for the Customizing Splash Screen example to experiment further.