Java3D via Web Start

Question

Is there a way to specify in the jnlp the requirements of the java3D installation to be able to run this application?

Answer 1

I got most of this information from a combination of searching these forums, the Web Start Developer's Guide, at http://java.sun.com/products/javawebstart/docs/developersguide.html, and the Unofficial JNLP/Web Start FAQ, which is at http://lopica.sourceforge.net/faq.html. Any mistakes or misconceptions in this explanation are my own, but if it leaves you confused or if I have failed to answer any questions, those are the documents that allowed me to get a Java3D application running via Web Start.
First important point: you WILL NEED to sign all the .jars you distribute, so if you don't know how to do that, go read a tutorial on security and jarsigner/keystores FIRST. You can create your own cert to sign against, so long as your users trust you enough to click 'Yes' when Web Start asks them if they trust you. :)
So, now you've gotten yourself set up with a signing cert, either your own or a $400 one from Verisign or similar. Now, you're going to need to sign copies of your application .jar, any other .jars you distribute (log4j.jar, the java3d jarfiles from the java3d distribution, in my case I have a data .jar that's separate from the application code .jar, etc.) Note that, to make Web Start transparently distribute the Java3D jars along with your application, you do in fact have to unpack them from the installer, sign them, and include them in the way I outline below. The approach I take is to copy all the files to some directory as unsigned.<original jar name>. Then, the jarsigner command line looks like this:
jarsigner -keystore /path/to/keystore/file -storepass <password> -keypass <other password> -signedjar <original jar name> unsigned.<original jar name> keyAlias This applies equally for any other .jars you distribute (log4j is a popular example), including your own application .jar.
If you use ant, the <signjar> task will do all the above for you! Have a look at the Ant manual.
Put all these signed jarfiles in some directory where your web server can serve them up, e.g., /var/www/<yourapp>/lib on the Web Start server. Now all the pieces needed are in place and securely signed so that Web Start will trust your application to use them; you just have to tell Web Start to make them available to the runtime classpath. Below are my .jnlp file and main() method from my java3d application. Note especially the <security> stanza of the JNLP file, which is what both requires the signing of all the .jars, and allows Java3D to talk to the DirectX or OpenGL layer, access files stored on disk (the .jars in the Web Start cache, for example), and
just generally behave as a native app might.
First the JNLP file:
<?xml version="1.0" encoding="utf-8"?>
<!-- JNLP File for Your Application -->
<jnlp
  spec="1.0+"
  codebase="http://your.webstart.server/yourapp"
  href="http://your.webstart.server/yourapp/yourapp.jnlp">
  <information>
    <title>Your Application</title>
    <vendor>Some Company</vendor>
    <!--<homepage href="docs/help.html"/> -->
    <description>This is your application</description>
    <description kind="short">A longer application description</description>
    <!-- <icon href="images/swingset2.jpg"/> -->
    <offline-allowed/>
  </information>
  <security>
      <all-permissions/>
  </security>
  <resources>
       <j2se version="1.4.2" href="http://java.sun.com/products/autodl/j2se" initial-heap-size="64m" />
       <jar href="http://your.webstart.server/yourapp/lib/yourApplication.jar"/>
       <jar href="http://your.webstart.server/yourapp/lib/some3rdPartyLibrary.jar"/>
  </resources>
  <resources os="Windows">
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/windows/j3daudio.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/windows/j3dcore.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/windows/j3dutils.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/windows/vecmath.jar"/>
    <nativelib href="http://your.webstart.server/yourapp/heartcad/lib/core/Java3D/jars/j3d/windows/j3dDLL.jar"/>
  </resources>
  <!-- Linux IBM J2RE 1.3.0 -->
  <resources os="Linux" arch="x86">
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3daudio.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3dcore.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3dutils.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/vecmath.jar"/>
    <nativelib href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3d.so.jar"/>
  </resources>
  <!-- Linux SUN JRE1.3.1 -->
  <resources os="Linux" arch="i386">
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3daudio.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3dcore.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3dutils.jar"/>
    <jar href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/vecmath.jar"/>
    <nativelib href="http://your.webstart.server/yourapp/lib/core/Java3D/jars/j3d/linux/i386/j3d.so.jar"/>
  </resources>
  <application-desc main-class="com.some.company.yourapp.YourApp"/>
</jnlp> And then the main() method:
     public static void main(String[] args) throws Exception {
          if(System.getProperty("javawebstart.version") != null) {
               // for Web Start it is necessary to "manually" load in native libs
               String os = System.getProperty("os.name");
               log.debug("loading " + os + " native libraries ..");
               if (os.startsWith("Windows")){
                    // order matters here!
                    // load those libs that are required by other libs first!
                    log.debug("j3daudio.dll .. ");
                    // drop ".dll" suffix here
                    System.loadLibrary("j3daudio");
                    log.debug("OK");
                    log.debug("J3D.dll .. ");
                    System.loadLibrary("J3D");
                    log.debug("OK");
               } else if (os.equals("Linux")){
                    log.debug("libj3daudio.so .. ");
                    // drop "lib" prefix and ".so" suffix
                    System.loadLibrary("j3daudio");
                    log.debug("OK");
                    log.debug("libJ3D.so .. ");
                    System.loadLibrary("J3D");
                    log.debug("OK");
               } else {
                    throw new Exception("OS '" + os + "' not yet supported.");
          // and then launch the app
          new MainFrame(new yourApp(), width, height);
     }