XML processing (Input & Output)

Question

Hi All,
I am developing a server application that needs to wrap and unwrap an XML document in an XML wrapper (envelope)
The wrapper looks like this (very simplified):
<Wrapper>
    <Element_x>xxx</Element_x>
    <Element_y>xxx</Element_y>
    <Element_z>xxx</Element_z>
    <Message>
         <!-- Actual message will go here. -->
    </Message>
</Wrapper>I have to be able to wrap messages by putting them inside the Message element in the header and be able to unwrap them by removing the wrapper (keeping only what's inside the Message element).
Could you please make suggestions of how this can be done efficiently? Most examples I could find uses the DOM for output which is not really suitable for performance reasons. Is there an API that can be used for this or should I use standard text IO?
Thank you in advance,
Herman

Answer 1

Mmmh, hard to quantify. You basically XSLT (http://www.w3schools.com/xsl/default.asp) and XPath (http://www.w3schools.com/xpath/default.asp) knwoledge. The good thing is that XSL is written in XML, so you won't be lost. Moreover your problem is quite simple.
Without any garantee, your XSL should look pretty much like this:
<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
  <xsl:copy>
    <xsl:apply-templates select ="Message/*"/>
  </xsl:copy>
</xsl:template>
</xsl:stylesheet>In term of Java API, it is a matter of a handfull of classes in and under the javax.xml.transform package.
Good luck,
David