The Java Tutorials have been written for JDK 8. Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.
See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.
The specification for StAX, JSR 173, does not yet support the new properties. However, StAX in the context of JAXP does include the support of these properties. Setting the new properties is similar to SAX or DOM, but through the XMLInputFactory as follows:
XMLInputFactory xif = XMLInputFactory.newInstance();
xif.setProperty("http://javax.xml.XMLConstants/property/accessExternalDTD", "file");
The existing properties and features specified in the StAX, JSR 173 specification will take preference over the new JAXP properties. The SupportDTD property for example, when set to false, will cause a program to throw exception when an input file contains DTD before it can be parsed. For applications that uses the SupportDTD property to disable DTD therefore, the addition of the new properties shall have no effect.