Tarantella uses Java™ applets for a variety of purposes. These Java applets must be downloaded from the Tarantella server to the client device's web browser.
The files that make up each applet can be combined into a Java archive. Java archives are useful because:
Web browsers can keep local copies of Java archives either by caching them, or locally installing them:
The Java archives in Tarantella work correctly with all supported browsers. However, some browsers have settings which can disable support for Java archives. If you have changed a particular browser's configuration, the browser may be unable to cache or install Java archives. You can always re-enable Java archive support by returning the browser to its default configuration.
Tarantella provides several types of Java archive,
as different web browsers support different types of archive. Tarantella
uses the mappings in the install_dir/etc/data/archives.txt file
to control which archive types are used with which browsers.
The table below shows:
archives.txt to use an archive type;| Setting | Archive type | Compression | Local copy | Signed |
|---|---|---|---|---|
| cab | Microsoft cabinet files | Compressed | Cached | Signed |
| cab4 | Microsoft distribution units | Compressed | Installed | Signed |
| jpsjar | Archives signed using the Sun JDK™ suitable for Sun's Java Plug-in | Compressed | Cached | Signed |
| nsjar | Netscape signed installable Java archives | Compressed | Installed | Signed |
| sjar | Netscape signed non-installable Java archives | Compressed | Cached | Signed |
| zip | Zip archives | Uncompressed | Cached | Not signed |
Note Netscape signed Java archives can be used with non-Netscape browsers.
By default, Tarantella uses these settings for the following browsers:
| Browser/platform | Setting |
|---|---|
| Microsoft Internet Explorer 5 on Windows | cab4 |
| Microsoft Internet Explorer 6 on Windows using the Microsoft Virtual Machine | cab4 |
| Microsoft Internet Explorer 6 on Windows using the Sun Java Plug-In | jpsjar |
| Microsoft Internet Explorer on Apple Mac OS X 10.2+ | jpsjar |
| Netscape 6.x and 7.x | jpsjar |
Note The cab4 setting used by default for Internet Explorer users on Windows means that the archive is installed locally. However, the ability to install archives locally requires Administrator privileges. If Tarantella detects that the user does not have these privileges, it will automatically use the cab archive type instead as this is cached rather than installed.
If the archive types used by default are unsuitable, you can
edit the install_dir/etc/data/archives.txt file to change
which archive types users receive. The file contains comments to help you
customize archive delivery.
If you only need to temporarily override the settings in the
archives.txt file so that you use a different Java archive, you can do
this by running the Tarantella CGI program ttaarchives.cgi with a query string.
This program sets a cookie which overrides archives.txt. For example,
using the URL http://server/tarantella/cgi-bin/ttaarchives.cgi?cab
sets your session to use the Microsoft cabinet archive.
The cookie lasts for as long as you have your web browser running.
The cookie is deleted when you close the web browser.
You can find full details on the query string settings available for ttaarchives.cgi by running:
http://server/tarantella/cgi-bin/ttaarchives.cgi?
When a web browser caches or installs a Java archive, the user is usually prompted for permission to cache/install the archive. For the archive to be cached/installed, the user must grant permission.