Unable to run jnlp using Open Webstart Java 8

Question

My application is developed on oracle jdk8 and UI is written in javafx. UI runs with javaws however, it openWebstart fails to launch same UI with error "Application Error: Not a launchable JNLP file". Below are log snippets:

[ITW-CORE][2023-10-25 16:00:51.610 IST][INFO ][net.sourceforge.jnlp.Parser] good - your JRE - 1.8.0_372 - match requested JRE - 1.8+
[ITW-CORE][2023-10-25 16:00:51.630 IST][ERROR][net.sourceforge.jnlp.AbstractLaunchHandler]
netx: Application Error: Not a launchable JNLP file.
net.sourceforge.jnlp.LaunchException: Fatal: Application Error: Not a launchable JNLP file. File must be a JNLP application, applet, or installer type.
    at net.sourceforge.jnlp.Launcher$TgThread.run(Launcher.java:670)
[ITW-CORE][2023-10-25 16:00:51.631 IST][ERROR][net.sourceforge.jnlp.Launcher]
Launch exception
net.sourceforge.jnlp.LaunchException: Fatal: Application Error: Not a launchable JNLP file. File must be a JNLP application, applet, or installer type.
    at net.sourceforge.jnlp.Launcher$TgThread.run(Launcher.java:670)
[ITW-CORE][2023-10-25 16:00:59.350 IST][INFO ][net.sourceforge.jnlp.util.logging.OutputController] Increase polling interval for shutdown phase
[ITW-CORE][2023-10-25 16:00:59.357 IST][INFO ][net.adoptopenjdk.icedteaweb.resources.cache.CacheImpl] No other instances of javaws are running

Downloaded OWS from their official site. Made it as a default application for opening jnlp files. Added Java 1.8 in JVM Manager in OWS settings

Jnlp file:

<?xml version="1.0" encoding="ISO-8859-1"?>
<jnlp spec="1.0+" codebase="http://172.17.147.60:18080/pwui" href="pwui.jnlp">
   <information>
      <title>Management Client</title>
      <icon kind="shortcut" href="image.jpg"/> 
      <shortcut online="true">
         <desktop/>
      </shortcut>
   </information>
   <resources>
      <j2se version="1.8+" java-vm-args="-XX:MaxPermSize=256m" />
      <jar href="Client.jar" main="true" />
      <jar href="Common.jar" main="false" />
      <jar href="EJBClient.jar" main="false" />
      <jar href="jnlp.jar" main="false" />
      <jar href="jbossall-client.jar" main="false" />
      <jar href="FXExperienceControls.jar" main="false" />
      <jar href="commons-codec-1.7.jar" main="false" />
      <jar href="commons-io.jar" main="false" />
      <jar href="itextpdf-5.4.1.jar" main="false" />
   </resources>
   <security><all-permissions/></security>
   <jfx:javafx-desc  main-class="com.client.fx.login.LoginScreen" />
   <update check="always" policy="always" />
</jnlp>

Answer 1

As far as I know IcedTea-Web, which is used under the hood of OpenWebStart does not have support for jfx:javafx-desc.

Instead you need to have an application-desc that defines the main class.

Also see this OpenWebStart FAQ entry: https://openwebstart.com/docs/FAQ.html#_how_to_run_openjfx_based_javafx_applications_with_openwebstar