J2EE Interview questions and answers

321. What is well-formed

An XML document that is syntactically correct. It does
not have any angle brackets that are not part of tags,
all tags have an ending tag or are themselves
self-ending, and all tags are fully nested. Knowing
that a document is well formed makes it possible to
process it. However, a well-formed document may not be
valid. To determine that, you need a validating parser
and a DTD.

322. What is Xalan

An interpreting version of XSLT.



323. What is XHTML

An XML look-alike for HTML defined by one of several
XHTML DTDs. To use XHTML for everything would of
course defeat the purpose of XML, because the idea of
XML is to identify information content, and not just
to tell how to display it. You can reference it in a
DTD, which allows you to say, for example, that the
text in an element can contain < em > and < b > tags
rather than being limited to plain text.

324. What is XLink

The part of the XLL specification that is concerned
with specifying links between documents.

325. What is XLL

The XML Link Language specification, consisting of
XLink and XPointer.



326. What is XML

Extensible Markup Language. A markup language that
allows you to define the tags (markup) needed to
identify the content, data, and text in XML documents.
It differs from HTML, the markup language most often
used to present information on the Internet. HTML has
fixed tags that deal mainly with style or
presentation. An XML document must undergo a
transformation into a language with style tags under
the control of a style sheet before it can be
presented by a browser or other presentation
mechanism. Two types of style sheets used with XML are
CSS and XSL. Typically, XML is transformed into HTML
for presentation. Although tags can be defined as
needed in the generation of an XML document, a
document type definition (DTD) can be used to define
the elements allowed in a particular type of document.
A document can be compared by using the rules in the
DTD to determine its validity and to locate particular
elements in the document. A Web services application's
J2EE deployment descriptors are expressed in XML with
schemas defining allowed elements. Programs for
processing XML documents use SAX or DOM APIs.

327. What is XML registry

An infrastructure that enables the building,
deployment, and discovery of Web services. It is a
neutral third party that facilitates dynamic and
loosely coupled business-to-business (B2B)
interactions.



328. What is XML Schema

The W3C specification for defining the structure,
content, and semantics of XML documents.

329. What is XPath

An addressing mechanism for identifying the parts of
an XML document.

330. What is XPointer

The part of the XLL specification that is concerned
with identifying sections of documents so that they
can be referenced in links or included in other
documents.