Get method documentation [Android Documentation]

Indicates whether or not the factory is configured to produce parsers which validate the XML content during parse.

Set method documentation [Android Documentation]

Specifies that the parser produced by this code will validate documents as they are parsed. By default the value of this is set to false.

Note that "the validation" here means as defined in the XML recommendation. In other words, it essentially just controls the DTD validation. (except the legacy two properties defined in JAXP 1.2. See for more details.)

To use modern schema languages such as W3C XML Schema or RELAX NG instead of DTD, you can configure your parser to be a non-validating parser by leaving the DocumentBuilderFactory.Validating method false, then use the DocumentBuilderFactory.Schema method to associate a schema to a parser.