JAXP XPath expression compare Documents

[Jeff Higgins]

Hi all
Newbie to XPath. Can someone help with
an XPath expression(s) that will accomplish
the following using JAXP in J2SE-1.5.
Thanks
Jeff Higgins

In a class I have two private org.w3c.dom
Document fields; Directories,and FileList,
that are populated as below;

In a method I would like populate two
org.w3c.dom NodeSets with element nodes
as below:

populate absentInDirectories with
FileList file elements whose
text() value cannot be found in all
Directories filepath elements text() value.

populate absentInFileList with
Directories filepath elements whose
text() value cannot be found in
all FileList file elements text() value.

<directories>
<directory>
<file>
<filename>bar1.txt</filename>
<filepath>c:\bar1.txt</filepath>
</file>
<directory>
<file>
<filename>bar2.txt</filename>
<filepath>c:\foo\bar1.txt</filepath>
</file>
</directory>
</directory>
</directories>

<filelist>
<file>c:\bar1.txt</file>
<file>c:\foo2\barfly.doc</file>
</filelist>