Calling Java Android code from XSLT

Question

I am trying to get an XSLT stylesheet to work that invokes Java code at certain points during execution (used to parse RDFa). You can find a very simple example of such code below:
<?xml version="1.0" encoding="UTF-8"?>
<stylesheet
xmlns:xsl ="http://www.w3.org/1999/XSL/Transform" version="1.0"
xmlns ="http://www.w3.org/1999/XSL/Transform"
xmlns:xalan="http://xml.apache.org/xalan"
xmlns:java="http://xml.apache.org/xalan/java"
exclude-result-prefixes="java" >
<xsl:template match="/">
<value-of select="java:android.xslt_test.XSLTTest.testing()"/>
</xsl:template>
</stylesheet>
Although this XSLT calls the specified method for a Java desktop application, it doesn't do anything in an Android application (no methods are called and the transformer simply returns the original document). After I configured the Transformer instance with a custom ErrorListener subclass instance (via aTransformer.setErrorListener()), I get a NullPointerException (packaged as a TransformerException) when the above XSLT code is parsed. This error does not occur for "normal" XSLT sheets (these are parsed correctly on Android).
Any ideas on why this doesn't work? Do I need to use another prefix / namespace for Android applications? I've spent quite some time looking online for a solution, but couldn't find any..
Thanks,
William

Answer 1

The question really comes down to "can I call a server-side object from the client side?"
The answer is "not directly". You can call a client-side JavaBean from JavaScript (e.g. when you use <jsp:plugin/> to embed a JavaBean in the HTML, you can call that from the JavaScript on the client-side.) You can call a server-side JavaBean using server-side code only.
You can probably set up a framework to cause a function on the client to submit to a servlet which changes the bean on the server, but you can't just call it directly.