The DOM API is filled with design patterns, especially creational patterns: package consists solely of interfaces), which can let a misbehaved program wreak havoc in a shared environment such as an app-server.
The XML specification requires that an XML document either have a prologue that specifies its encoding, or be encoded in UTF-8 or UTF-16.
But in this example I used a Java String, which is UTF-16 encoded, without a prologue. The answer is that the parser did not read the string directly.
Instead it read from an doesn't match the actual content.
In this article, i am going to use the Swing for the UI purpose and for the XML validation against its schema i will use DOM parser as well as SAX Parser.
previously we have already seen that how these parsers works in detail.
And that brings up the second case: if you get XML from someone who doesn't know the rules.
Except for one small problem: the Namespace spec was introduced in 1999, while the DOM level 1 spec was released in 1998 and knew nothing of namespaces.The Document Type Definition is part of the XML specification.A DTD describes the organization and content of an XML document in a form similar to Backus-Naur notation: a tree structure in which each element specifies the elements that it may contain (potentially none), and the order in which they must appear.A third option is Relax NG, which tries to find a middle ground between DTD's lack of expressiveness and XSD's Byzantine structure. Before continuing, I want to add a third, non-standard term to describe XML documents: “correct.” A validator can only check the existence, ordering, and general content of an XML file; it's equivalent to the syntax check of a Java compiler.
Whether that content is actually usable by your application is another question — just like a syntactically correct program may be full of logic bugs.I once saw an attempt to use XSD to validate relationships in a complex object graph; the developer gave up after creating a schema document.