john smith wrote:
I am having to read an XML document and grab some elements and attributes
and then convert that to anther XML document.
Which should I use? JAX, DOM, JDOM?
I don't really understand the difference and when to use the above.
DOM usually means the W3C DOM specification which is meant to be
language independent by using some IDL (interface description language)
to define a tree based API for manipulating XML (and HTML) documents.
The W3C DOM specification then goes on to define two language bindings,
one for Java, one for ECMAScript. As the specification should be
implementable on top of existing implementations and as the API has to
work with scripting languages with loose typing as well as with
languages like Java with strong typing the Java binding the W3C suggests
for the DOM doesn't define any classes but only interfaces to be
implemented. Where overloading in Java would be possible it is not done
as overloading in ECMAScript is not possible and the API is meant to be
consistent in different languages.
As a result of this many pure or main Java programmers dislike the W3C
DOM and have implemented Java specific and Java natural DOM APIs, one of
which is JDOM. But there are others like XOM.
JAXP is Sun's term for the different XML related Java APIs in the Sun
Java development kit/JDK, it is mainly an abstraction layer (or even
several ones) to allow you to use different parsers or DOM
implementations or XSLT implementations or XPath implementations that
are around under a common way to create parsers.
What you should or want to use depends on many criteria, Sun Java 1.4
and Sun Java 1.5 have W3C DOM support thus if you want to only rely on
the classes installed by the Sun JDK/JRE then you do not have JDOM for
instance or XOM. You would need an additional download for that and
anyone using your software too.
--
Martin Honnen
http://JavaScript.FAQTs.com/ 
