Java Foundation Classes in a Nutshell

Consider the simple HTML file we used for the first applet example in this chapter:

<APPLET code="MessageApplet.class" width=350 height=125>

<PARAM name="message" value="Hello World">

</APPLET>

When run through the HTML converter, this tag becomes something like this:

<OBJECT classid="clsid:8AD9C840-044E-11D1-B3E9-00805F499D93"

codebase=

"http://java.sun.com/products/plugin/1.2/jinstall-12-win32.cab#Version=1,2,0,0"

WIDTH=350 HEIGHT=125>

<PARAM NAME=CODE VALUE="MessageApplet.class" >

<PARAM NAME="type" VALUE="application/x-java-applet;version=1.2">

<PARAM NAME="message" VALUE="Hello World">

<COMMENT>

<EMBED type="application/x-java-applet;version=1.2"

pluginspage=

"http://java.sun.com/products/plugin/1.2/plugin-install.html"

java_CODE="MessageApplet.class"

WIDTH=350 HEIGHT=125 message="Hello World">

</EMBED>

</COMMENT>

</OBJECT>

When Navigator reads this HTML file, it ignores the <OBJECT> and <COMMENT> tags

that it does not support and reads only the

<EMBED> tag. When Internet Explorer

reads the file, however, it handles the

<OBJECT> tag and ignores the <EMBED> tag

that is hidden within the

<COMMENT> tag. Note that both the <OBJECT> and <EMBED>

tags specify all the attributes and parameters specified in the original file. In addi-

tion, however, they identify the plug-in or ActiveX control to be used and tell the

br owser fr om wher e it can download the Java Plug-in, if it has not already down-

loaded it.

You can ...