Application versus Applet

What is an applet?

An applet is a diminutive application (applicationet).
An applet is an emasculated program.
- It can't load libraries or define native methods.
- It can't ordinarily read or write local files.
- It can only make network connections to the host from which it came.
- It can't start a local program.
- It can only read some system property.
- Applet windows look different than application windows.
Applets can do many things.
- Applets running within a Web browser can cause HTML documents to be displayed.
- Applets can invoke public methods of other applets on the same page.
- Local applets do not have the restrictions that applets loaded over the network do.
- Applets do not need to stop running when you leave their page.

Sample applet

Calls image display routine
Includes parameters for display
Includes message for non applet compliant browsers

<HTML>
<HEAD>
<TITLE>Tony's Image Display</TITLE>
</HEAD>

<BODY>

<h1 align=center>Tony's Image Display</h1>

<applet codebase=. code=ImageTony.class width=500 height=400>
<PARAM NAME=IMAGEFILE VALUE="images/BoneScan.gif">
<PARAM NAME=IMAGETYPE VALUE="GIF">
<PARAM NAME=FRAMEHEIGHT VALUE="128">
<PARAM NAME=FRAMEWIDTH VALUE="128">
<PARAM NAME=PATIENTNAME VALUE="Doe, John Q.">
<PARAM NAME=MRN VALUE="123-45-67">
<PARAM NAME=STUDYDATE VALUE="21-March-1996">
<PARAM NAME=STUDYTYPE VALUE="Miscellaneous">
<hr><blockquote>
<em>Your browser doesn't understand the &lt;APPLET&gt; tag.</em>
</blockquote>
<hr>
</applet>

<address>J. Anthony Parker, MD PhD</address>
<p>
</BODY>
</HTML>

Table of Contents

J. Anthony Parker, MD, PhD, Tony_Parker@bih.harvard.edu