This is a feature of JBuilder Professional and Enterprise.
The XML to DTD wizard creates a DTD file from an XML document.
To open the XML to DTD wizard, choose File|New, click the XML tab in the object gallery, and double-click the XML to DTD icon.
Browse to and select the XML document you want to generate the DTD file from.
Note: If you select the XML file in the project pane before running the wizard, this field is automatically filled in for you.
Choose the ellipsis button and eEnter the name of the DTD file you want to create in the File Name field.