Problems with java and JDOM

Hi all...Im getting to learn XML in java.
I have this little example in java

import java.io.*;
import org.jdom.*;
import org.jdom.input.*;
import org.jdom.output.*;
public class PrettyPrinter {
   public static void main(String[] args) {
        // Assume filename argument
        String filename = args[0];
        try {
            // Build the document with SAX and Xerces, no validation
            SAXBuilder builder = new SAXBuilder();
            // Create the document
            Document doc = builder.build(new File(filename));
            // Output the document, use standard formatter
            XMLOutputter fmt = new XMLOutputter();
            fmt.output(doc, System.out);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

I suppose that i did a good job setting up jdom for java (if you have nice instructions on how to setup this in windows..would be highly appeciated :)) Compilation process goes fine, but when i run it i get this message

[Document: No DOCTYPE declaration, Root is[Element: <myRootElement/>]]

and this happens with every single example i try in java..is there a solution for that?? thank you for your help!!