Is DocumentBuilder.parse() thread safe?

Question

Is the standard Java 1.6 javax.xml.parsers.DocumentBuilder class thread safe? Is it safe to call the parse() method from several threads in parallel?

The JavaDoc doe

Answer 1

Even though DocumentBuilder.parse appears not to mutate the builder it does on the Sun JDK default implementation (based on Apache Xerces). Eccentric design decision. What can you do? I guess use a ThreadLocal:

private static final ThreadLocal builderLocal =
    new ThreadLocal() {
        @Override protected DocumentBuilder initialValue() {
            try {
                return
                    DocumentBuilderFactory
                        .newInstance(
                            "xx.MyDocumentBuilderFactory",
                            getClass().getClassLoader()
                        ).newDocumentBuilder();
            } catch (ParserConfigurationException exc) {
                throw new IllegalArgumentException(exc);
            }
        }
    };

(Disclaimer: Not so much as attempted to compile the code.)