Hi Joe, thanks for your comments.
Yes the customer does not really want to insert a null value but create an empty text node. So they'll fix their code anyway. However, I thought it would be a good Idea to make the Serializer more robust with regards to such null data. Especially given that it's possible via the DOM API to construct such null nodes. So I take you support this endeavor? Thanks Christoph From: huizhe wang [mailto:huizhe.w...@oracle.com] Sent: Dienstag, 8. November 2016 06:01 To: Langer, Christoph <christoph.lan...@sap.com>; Aleks Efimov <aleksej.efi...@oracle.com>; Lance Andersen <lance.ander...@oracle.com> Cc: core-libs-dev@openjdk.java.net Subject: Re: XALAN: Text node of value 'null' - Is this illegal or does XSLTC have an issue here? Looks like a null check-in is desirable. If the intention is to add a text node, which I assume was his intention, he wouldn't want a null node. If the intention is to create an empty element, then he didn't need the line that added the null text node. As far as DOM goes, it would have been better if it was clearer on how null be handled (a DOMException probably). But for a 10+ yr old API, the case is not enough to call for a change of the behavior. Thanks, Joe On 11/7/2016 8:09 AM, Langer, Christoph wrote: Hi Xalan experts, I've recently handled a customer issue about Text Nodes of value 'null' inside a DOM, causing an exception during XALAN XSLT transformation. The repro case is quite simple. Consider the following small Java sample [1] which creates a DOM from a very basic XML, inserts a text node with value null into the DOM and then runs an identity transformation on it. Without inserting the null Text node, it would run without issues. However, the com.sun.org.apache.xml.internal.serializer.ToUnknownStream class stumbles over the null value and the transformation throws an NPE [2]. I believe this could be easily fixed by adding a null check in the serializer and handling null like "". However, would you agree that it is a real issue worth fixing or should one rather stress the point that Text Nodes of null are illegal? (Is that true, anyway? Didn't find any specification about that...) Please let me know your opinion - and if you agree I would work on a fix. Thanks in advance for comments Christoph [1] Sample code: import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.TransformerException; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.xml.sax.SAXException; public class TestTransformWithNullText { public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException, TransformerException { // create a small DOM DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder(); Document doc = db.parse(new ByteArrayInputStream("<?xml version=\"1.0\"?><DOCROOT/>".getBytes())); // insert a bad element Element e = doc.createElement("ERROR"); e.appendChild(doc.createTextNode(null)); doc.getDocumentElement().appendChild(e); // transform ByteArrayOutputStream bos = new ByteArrayOutputStream(); TransformerFactory.newInstance().newTransformer().transform( new DOMSource(doc.getDocumentElement()), new StreamResult(bos)); System.out.println(bos); } } [2] Exception encountered: Exception in thread "main" javax.xml.transform.TransformerException: java.lang.NullPointerException at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(java.xml@9.0.0.1-internal/TransformerImpl.java:789<mailto:java.xml@9.0.0.1-internal/TransformerImpl.java:789>) at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(java.xml@9.0.0.1-internal/TransformerImpl.java:376<mailto:java.xml@9.0.0.1-internal/TransformerImpl.java:376>) at com.sap.cl.xml.test.transform.TestTransformWithNullText.main(TestTransformWithNullText.java:33) Caused by: java.lang.NullPointerException at com.sun.org.apache.xml.internal.serializer.ToUnknownStream.characters(java.xml@9.0.0.1-internal/ToUnknownStream.java:342<mailto:java.xml@9.0.0.1-internal/ToUnknownStream.java:342>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:244<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:244>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:230<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:230>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:230<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:230>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:94<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:94>) at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transformIdentity(java.xml@9.0.0.1-internal/TransformerImpl.java:718<mailto:java.xml@9.0.0.1-internal/TransformerImpl.java:718>) at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(java.xml@9.0.0.1-internal/TransformerImpl.java:780<mailto:java.xml@9.0.0.1-internal/TransformerImpl.java:780>) ... 2 more --------- java.lang.NullPointerException at com.sun.org.apache.xml.internal.serializer.ToUnknownStream.characters(java.xml@9.0.0.1-internal/ToUnknownStream.java:342<mailto:java.xml@9.0.0.1-internal/ToUnknownStream.java:342>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:244<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:244>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:230<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:230>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:230<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:230>) at com.sun.org.apache.xalan.internal.xsltc.trax.DOM2TO.parse(java.xml@9.0.0.1-internal/DOM2TO.java:94<mailto:java.xml@9.0.0.1-internal/DOM2TO.java:94>) at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transformIdentity(java.xml@9.0.0.1-internal/TransformerImpl.java:718<mailto:java.xml@9.0.0.1-internal/TransformerImpl.java:718>) at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(java.xml@9.0.0.1-internal/TransformerImpl.java:780<mailto:java.xml@9.0.0.1-internal/TransformerImpl.java:780>) at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl.transform(java.xml@9.0.0.1-internal/TransformerImpl.java:376<mailto:java.xml@9.0.0.1-internal/TransformerImpl.java:376>) at com.sap.cl.xml.test.transform.TestTransformWithNullText.main(TestTransformWithNullText.java:33)
