JDOMException: root element required in a well-formed document

Question

Ok, my XML file looks something like this:
<?xml version="1.0" ?>
<this>
<that></that>
</this>
... and my Java code to build a JDOM object model from the XML file (Xerces-parsed) looks somethings like this:
Document theDoc;
SAXBuilder theBuilder;
InputSource = theSource;
theBuilder = new SAXBuilder("org.apache.xerces.parsers.SAXParser");
theDoc = builder.build(theSource);
Now, when I compile and run, I get a JDOMException that looks something like this:
org.jdom.JDOMException: Error on line 1 of document : The root element is required in a well-formed document.
What's up with that?

Answer 1

(1) Thanks for taking the time. I'm not sure how I could make more than one root element. All I know is, in my XML file, the element tag that comes right after the <? xml version="1.0" ?> line has the same name as the very last tag in the file (with a "/" added before the name). There are no other elements in the file with that name, so I figure that makes it (ie. <this></this>) the root element of my document. N'est pas?
(2) I have some more info since I originally posted:
I added the following line:
"System.err.println(e.getCause());"
... to the catch() area that throws the JDOMException - like follows:
try {
theCurrentDocument = builder.build( docFile ); // builder is an object created with <i>builder = new SAXBuilder("org.apache.xerces.parsers.SAXParser");</i>
docType_CurrentDoc = theCurrentDocument.getDocType();
root_CurrentDoc = theCurrentDocument.getRootElement();
catch( org.jdom.JDOMException e ) {
System.err.println(e); // Caused the original JDOMException from my first post
System.err.println(e.getCause()); // Line I added since my first post
The amended code above produced an extra line of output to the console:
"java.security.AccessControlException: access denied (java.io.FilePermission \myfile.xml read)"
Which I take to mean that I have to sign my applet. Is there any way around doing that? Because I don't want to if I don't have to.