348.8.

SimpleRegistry registry = new SimpleRegistry();
registry.put("function1", new MyExtensionFunction1());
registry.put("function2", new MyExtensionFunction2());

CamelContext context = new DefaultCamelContext(registry);
context.addRoutes(new RouteBuilder() {
    @Override
    public void configure() throws Exception {
        from("direct:start")
            .to("xslt:org/apache/camel/component/xslt/extensions/extensions.xslt?saxonExtensionFunctions=#function1,#function2");
    }
});

<bean id="function1" class="org.apache.camel.component.xslt.extensions.MyExtensionFunction1"/>
<bean id="function2" class="org.apache.camel.component.xslt.extensions.MyExtensionFunction2"/>

<camelContext xmlns="http://camel.apache.org/schema/spring">
  <route>
    <from uri="direct:extensions"/>
    <to uri="xslt:org/apache/camel/component/xslt/extensions/extensions.xslt?saxonExtensionFunctions=#function1,#function2"/>
  </route>
</camelContext>