[news.eclipse.technology.buckminster] Re: exporting product for Java web

[Thomas Hallgren <thomas@xxxxxxx>]

Thomas Spiessens wrote:
> Hi Thomas,
> jnlp file generation works like a charm.
>
> Two questions though:
>
> 1. When the jnlp file gets generated, the value of the codebase 
> attribute is '$$codebase'. Is there a possibility to set a specific 
> value during JNLP file generation ?
At present, the behavior for the JNLP generator is fixed and the output is intended for use with a 
server that runs a JNLP servlet that performs certain tasks (like replacing the $$codbase with the 
appropriate value for that particular installation). See: 
http://java.sun.com/j2se/1.5.0/docs/guide/javaws/developersguide/downloadservletguide.html

The design is intended to be flexible so adding the needed parameters for a simpler setup should not 
be difficult. If you want to have a go at it, I suggest you have a look at our 
org.eclipse.buckminster.pde plugin. The relevant classes are found in the package 
org.eclipse.buckminster.pde.tasks and have names that start with JNLP.

The ant task that drives it all is found under the src/ant_tasks/org/eclipse/buckminster/pde/ant 
folder and the actual ant target is defined in the build.xml in package 
org.eclipse.buckminster.pde.antscripts.


> 2. When I export the jnlp file manually via the Eclipse IDE, the <jar> 
> elements look like this <jar 
> href="plugins/com.x.y_1.0.0.200801011000.jar"/>. The <jar> elements that 
> get generated by Buckminster look like this <jar 
> href="plugins/com.x.y.jar" version="200801011000"/>. When trying to 
> download the application via Web Start, the Buckminster-generated 
> version results in an HTTP 404 error when trying to download the 
> plugins. If I change it to the former format, then the download 
> succeeds. I'm not sure how web start maps that separate 'version' 
> attribute to an actual resource in the HTTP GET request it sends out. 
> Any idea why this is happening ?
Yes. Since file generated by Buckminster assumes that the server runs a JNLP servlet, it generates a 
version.xml file in the root that the servlet can make use of. In our case, that file looks 
something like this:

<?xml version="1.0" encoding="UTF-8"?>
<jnlp-versions>
    <resource>
        <pattern>
            <name>org.eclipse.buckminster.jnlp.product.jnlp</name>
            <version-id>0.2.0.r07461</version-id>
        </pattern>
        <file>org.eclipse.buckminster.jnlp.product_0.2.0.r07461.jnlp</file>
    </resource>
    <resource>
        <pattern>
            <name>startup.jar</name>
            <version-id>1.0.1.R33x_v20070828</version-id>
        </pattern>
        <file>startup.jar</file>
    </resource>
</jnlp-versions>

Regards,
Thomas Hallgren