Is XMLInputFactory thread-safe?

Question

When profiling my application, I noticed that creating instances of XMLInputFactory over and over is very expensive. Is it safe to share its instances across multiple threads?

The javadoc doesn't say anything about its thread-safety and searching the internet doesn't give a definite answer!

Ophite

Yes, it is thread safe. – Bareheaded

@Bareheaded Can you point me to some documentation or resource which discusses this? – Ophite

maybe it's not issues.apache.org/jira/browse/AXIOM-74 – Rianna

I peeked into OpenJDK sources and just configuration must be synchronized. But I must say, that it may depend upon implementation. XMLInputFactory itself is abstract! – Bareheaded

true. @Chandru what JDK are you using? – Rianna

not sure about jdk7, but check this out svn.codehaus.org/woodstox/wstx/trunk/release-notes/USAGE - it seems to be for woodstox – Rianna

@Rianna Looks like I added my answer at the same time as your comment. Provide it as an answer and I'll accept it. – Ophite

Hi, does anyone has an answer on this? – Dippold

Answer 1

I have decided to use Woodstox as the StAX implementation. It is both much faster than the default JDK implementation and explicitly mentions thread safety.

Woodstox factories are thread-safe after configuration phase (calling setProperty()), but not during it. Most importantly, once all configuration is done, calling 'createXMLxxx' methods is fully thread-safe.

Ophite