Re: [docbook-apps] java 1.5 and xsltc and endorsed stuff.

[Ian Atkin <ianatkin@blueyonder.co.uk>]

comments inline:-

Wendy Smoak wrote:
> From: "David Tolpin" <dvd@davidashen.net>
> 
>> The problem arises when it is called through JAXP — it then uses what 
>> javax.xml.transform.TransformerFactory returns, and the 
>> TransformerFactory itself is, naturally, the first one found in 
>> CLASSPATH.
>>
>> How to put Xalan's or Saxon's (6.5.3) TransformerFactory before the 
>> built-in xsltc, I don't know.
> 
> 
> I did convince Java 1.5 to use a replacement xalan.jar file by placing 
> it in $JRE_HOME/lib/endorsed.  (I had to create the 'endorsed' directory.)

basically this puts xalan on the classpath, but not in the "official" way:-

endorsed = override classes already in the JVM, like SAX or DOM

extension = add classes to the JVM, thus don't have to put them in the 
claspath

classpath = per execution variable

so there are three ways of using xalan in 1.5, isn't Sun great :-)

> 
> Another way to override the default behavior is to use a tool like Ant 
> that lets you specify the classpath it should use to find the XSLT 
> processor. After some false starts, the Ant xslt (or style) task is 
> working when told to use saxon.jar or xalan.jar.  This method probably 
> involves a custom ClassLoader, though I haven't looked at the Ant source 
> code to confirm.
> 

yes, <xslt> will try to find the first implementation on the classpath 
it's given, which can be done in a huge number of ways, the ant manual 
can explain this

however this logic is a royal pain the arse, a test I've just done by 
using:-

     <xsl:message>
       <xsl:value-of select="system-property('xsl:vendor')"/>
     </xsl:message>

confirms that the default on jdk 1.5 is xalan's compiler (which can't 
deal with the current docbook scripts), that putting saxon.jar on 
ANT_HOME/lib doesn't work when it should and that putting both xalan and 
saxon on the tasks's classpath in the build script makes the task choose 
the first one (swap them round and the output changes accordingly)

it's always been this messy, so i just use <java> and saxon's command 
line, sure a little more work in the build script but so much less 
hassle (and a better xslt processor to boot :-)

Ian