Browser Information

This file contains basic information on how browsers and applet viewers look for class files, how specific browsers support JDK1.1 applets, and the issues surrounding each one.

Contents:

How browsers look for class files
JDK 1.1 support
AppletViewer
HotJava
Netscape Communicator
Microsoft Internet Explorer

How Browsers look for class files

Browsers have a mechanism (browser specific) for specifying a local CLASSPATH. This CLASSPATH will contain the classes that were installed with the browser (typically the JDK classes at least).

When an applet needs a class, browsers typically look for classes first in their local CLASSPATH, then on the remote server. However, you can never count on that CLASSPATH for anything except the core language classes.

Applets don't have a CLASSPATH. CODEBASE can be used instead, but it is optional. All information needed to run an applet (except for the core language classes) must be found using the information inside the APPLET tag.

Note: Browsers will attempt to find classes in Java archives placed on the ARCHIVE attribute of the APPLET tag. They cannot locate classes in archives when the archive file isn't specified.

JDK 1.1 support

All the major browsers now are somewhat compliant with JDK 1.1. If, during your early JDK 1.1 development efforts, this is not widely the case, you can use the following tools and information to assist in viewing JDK 1.1 applets.

The information provided below is dated. Please visit the web sites of your favorite web browsers to see the current status of their support for JDK 1.1.

At the time of this writing,

Note: A new "plug in" for browsers allows developers to bypass the installed VM and use a JavaSoft JRE. See http://java.sun.com/products/activator/.

For additional JDK 1.1 browser support information, see the JBuilder Developer Support FAQ "Current web browser - Java 1.1 status" http://www.borland.com/devsupport/jbuilder/qanda/1467.html.

AppletViewer

The JavaSoft JDK 1.1 AppletViewer is integrated into JBuilder and used for running and debugging applets. It is fully JDK 1.1 compliant, of course. When you run or debug an applet in JBuilder, you are actually seeing its UI in AppletViewer. AppletViewer can also run stand-alone if you want to demo your applet separately from JBuilder and you do not have a JDK 1.1 compliant browser available.

AppletViewer supports multiple archives. The ARCHIVE tag needs to contain a quoted, comma separated list. The location of those files is determined by the other information in the HTML file. See Deploying JDK 1.1 applets as archives.

You can launch AppletViewer on the command line, pointing it at the HTML file containing the APPLET tag. If all your files are in the right locations, you simply need to change directories to the HTML file and run AppletViewer from there.

If this fails, you know immediately that some number of needed files are not where they need to be.

See the http://java.sun.com/products/jdk/1.0.2/tools/win32/appletviewer.html site for more information on AppletViewer.

Issues with AppletViewer

AppletViewer only shows the applet itself, not any of the other html content.

HotJava

HotJava 1.1.2, available from Sun, is an all-Java browser that is fully JDK 1.1 compliant. Note that Netscape and Sun have announced cooperation in creating an all-Java browser based on HotJava.

You can download the HotJava 1.1.2 browser binary free for individual, non-commercial use at http://java.sun.com/products/hotjava/1.1/index.html#download.

Note: You may need to fill out a form before downloading the latest HotJava.

See the Sun web site at http://java.sun.com/products/hotjava/1.1/ for more information about HotJava 1.1.

Netscape Communicator

Netscape has announced JDK1.1 support in an upcoming Communicator, and cooperation with Sun for using HotJava code in building a future all-Java browser.

See the Netscape web site at http://www.netscape.com for more information about Communicator.

Issues with Netscape browsers

You need to download Netscape's Final Release of the Windows 95 or NT JDK 1.1 support patch support patch to make Netscape 4.04 JDK 1.1 enabled. Communicator 4.04 is still not fully JDK 1.1 compliant. Netscape, so far, has only provided this patch for the Windows NT and Windows 95 platforms. This patch is currently not available for Unix.

With the release of Communicator 4.04, Netscape was able to support a large subset of the JDK 1.1. Additional JDK functionality provided by this patch includes: JNI (Win32) AWT 1.1 New Event Model JavaBeans Support Printing Support for Applets

Note: Netscape just released 4.05 of their browsers. 4.05 is no different than 4.04. It still has the same Java VM built into it. However. there is a "special" build of 4.05 with a "preview release" of a 1.1.5 VM and classes. It can be picked up from http://developer.netscape.com/software/jdk/download.html. Therefore, 4.05 with Java 1.1 support is a preview release, and subject to change in the near future. This is different from the 'normal' 4.05 release most people are going to pick up and install.

For more information, see

Microsoft Internet Explorer

Internet Explorer has supported the ARCHIVE tag since IE4 beta 2, and it also supports multiple archives.

IE4 also supports CAB archives (cabinet files). Use the CABBASE tag to refer to all .cab files used by your applet. Since support of CAB archives is a Microsoft specific enhancement, other browsers will not recognize the CABBASE tag. To ensure users using browsers other than IE4 can run your applets, you must also have either JAR or ZIP archives containing the same files as the CAB archive. These .jar and .zip files must be referenced using the ARCHIVE tag.

If you're having problems deploying any archive (CAB, ZIP, or JAR), expand the archive onto the local system to see if that clears things up.

Issues with Microsoft Internet Explorer 4.0

See Microsoft's web site at http://www.microsoft.com for more information on Internet Explorer.