is TransformerFactoryImpl of Xalan is thread safe?

Is the class org.apache.xalan.processor.TransformerFactoryImpl thread safe? Or do I have to a keep loca开发者_如何学运维l copy for each thread?

According to the Xalan Transform API document:

A TransformerFactory may not perform mulitple concurrent operations.

It certainly doesn't look thread safe looking at the source

Looking closely in the source suggests that it should be thread safe in case you don't call setter methods after first initialization.