java

java overview
Java differs from ActiveX in many ways, most of which are covered in the ActiveX section. Java applets in web pages are generally used for small multimedia effects that go beyond the standard browser's HTML capabilities. For this tutorial, I'll show you how to implement a Java applet using the <applet> and <param> tags. For my sample applet, I've chosen an interesting program written by Fab Le Fantome: a twisted (pun intended) version of the normal 'ticker tape' scroller.

the <applet> tag
This is the code I used to display the applet above:

<applet code="Led.class" height=105 width=215>
<param name="message" value=" THIS IS A TEST OF THE BENT LED APPLET - USED FOR THE WEBWORKS JAVA TUTORIAL - ">
<param name="back_color" value="16777215">
<param name="back_image" value="bend.gif">
<param name="vDistortion" value=".85">
<param name="radius" value="88">
<param name="offX" value="14">
<param name="offY" value="9">
</applet>

This may look complicated, but it's actually very simple. First, the <applet> tag tells the browser the URL to the Java applet's code source, in this case, "Led.class". It also defines the height and width of the applet. Note that, although it may not make sense at first, the <applet> tag is a spanning tag. This is done for two reasons:

On browsers that support Java, all text inside the <applet> tag is completely ignored, with the exception of the few Java-specific tags covered later. However, for older, non-Java browsers, the text is processed normally and the tag is ignored. This makes it possible to do the following:

<applet code="myApplet.class" height=100 width=100>

<p>Your browser does not support Java.
Please download the latest version of Internet Explorer or Netscape.</p>

</applet>

This results in showing the Java applet only on supporting browsers, and informing less technically advanced users that they must download the latest browsing software in order to fully experience the page.
A spanning tag is capable of containing as many parameter settings as the user requires. These are covered in the next section:

the <param> tag
The other half of Java control implementation is the <param> tag. Java controls expose a set of properties that affect how it operates and displays. You can change these properties using the <param> tag. In the above code, I used the <param> tag to set up the background image, message properties, text, color, and display options. It requires only two parameters:

Name: The Name attribute tells the browser which property to set. The browser passes this on to the Java control to verify that it's a valid property.
Value: This is the value to set the parameter defined in the Name attribute to. In the above Java code, I set the message property to the text I wanted to have the applet display.

There are thousands of available Java controls, and each has a specific set of attributes that you can set using the <param> tag. For more info on the Bent LED applet that I used for this example, check out http://www.geocities.com/SiliconValley/8294/led.html. If you're looking for an applet that performs a general purpose, check out Gamelan and look through their bank of Java applets to see if on of theirs fits your purposes. If you're interested in learning to create your own applets, check out the Java home at http://java.sun.com for more information.

Good luck!

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