An extension function is invoked using a name such as prefix:localname(). The prefix is associated with a namespace declaration that is in scope.
The namespace URI is used to identify a Java class, and the local name is used to identify a method.
Examples:
xmlns:date=”java:java.util.Date” or xmlns:date=”http://www.jclark.com/xt/java/java.util.Date”
While using the Saxon implementation : http://saxon.sf.net/ points to the class net.sf.saxon.functions.Extensions except for saxon:evaluate
The command line option -TJ debugs the loading of Java extensions: detailed information about the possible matchings.
The call binding is always made at the time the XPath expression is compiled. If similar name, distance parameters.
Calling Static Methods in a Java Class date:static_method()
* Static methods can be called directly. hyphen notation toString becomes to-string in XQuery
* A static Java method called as an extension function may have an extra first argument of class net.sf.saxon.expr.XPathContext
Calling Constructors date:new()
* Java constructors are called by using the function named new()
* The only things that can be done with a wrapped Java Object are to assign it to a variable, to pass it to an extension function, and to convert it to a string, number, or boolean
Calling Java Instance-Level Methods date:to-string(date:new()) or date:to-string($e)
* Instance-level methods are called by supplying an extra first argument of type Java Object which is the object on which the method is to be invoked
CLASSPATH should contain the folder where Java Classes are stored!
Example in attached file XQuery extension example (.xq and .java)
