Deploying Java Applications using Java Web Start

Java Web Start enables applications to be deployed quickly and easily launched from a web server. Once launched using Web Start, an application can subsequently be directly launched using a desktop link on the client machine.

Typically, an application written in Java can be deployed quickly with a few simple steps. Java Web Start applications require all resources to be located within one or more jar files. Once you have packaged up your resources (classes, images etc.) into your jar file(s), you need to create a Java Network Launching Protocol (JNLP) file to be placed onto your web server. This file specifies all the properties required by your application, as well as any Web Start instructions required in order to launch the application.

Our sample Tradespace application is a good example of a Web Start application that uses the Universal Messaging Client API to consume simulated stock index prices, trades as well as news and chat. Below shows the contents of the JNLP file used to launch this application.

<?xml version="1.0" encoding="UTF-8"?>
<jnlp spec="1.0+" codebase="https://showcase.my-channels.com/demo/installers/java/"
href="https://showcase.my-channels.com/demo/installers/java/tradespace.jnlp">
<information>
<title>Nirvana Tradespace</title>
<vendor>my-channels.com</vendor>
</information>
<security>
<all-permissions/>
</security>
<update check="timeout" policy="always"/>
<resources>
<j2se java-vm-args="-Djavaws.cfg.jauthenticator=none" version="1.5+"/>
<jar href="https://showcase.my-channels.com/demo/installers/java/Tradespacedemo.jar"
download="eager" main="true"/>
<property name="sun.java2d.noddraw" value="true"/>
</resources>
<application-desc main-class="com.pcbsys.nirvana.apps.Tradespace"/>
</jnlp>

New versions of your application can be easily deployed to your customer base automatically by updating the resource jar files and deploying them to your web server. Java Web Start applications will automatically check for new versions before launching local cached versions.