Supported as strings only
import java.math.BigInteger; import java.io.*; import org.jdom.*; import org.jdom.output.XMLOutputter; public class InternalValidFibonacci { public static void main(String[] args) { Element root = new Element("Fibonacci_Numbers"); BigInteger low = BigInteger.ONE; BigInteger high = BigInteger.ONE; for (int i = 1; i <= 25; i++) { Element fibonacci = new Element("fibonacci"); Attribute index = new Attribute("index", String.valueOf(i)); fibonacci.setAttribute(index); fibonacci.setText(low.toString()); BigInteger temp = high; high = high.add(low); low = temp; root.addContent(fibonacci); } String dtd = "<!ELEMENT Fibonacci_Numbers (fibonacci*)>\r\n"; dtd += "<!ELEMENT fibonacci (#PCDATA)>\r\n"; dtd += "<!ATTLIST fibonacci index CDATA #IMPLIED>\r\n"; DocType type = new DocType("Fibonacci_Numbers"); type.setInternalSubset(dtd); Document doc = new Document(root, type); // serialize it into a file try { FileOutputStream out = new FileOutputStream("internalvalidfibonacci.xml"); XMLOutputter serializer = new XMLOutputter(); serializer.output(doc, out); out.flush(); out.close(); } catch (IOException e) { System.err.println(e); } } }View Output in Browser