Changing SAX?http://norman.walsh.name/2006/02/23/changingSAX 9 22 2006-02-23T09:58:18-05:00 $Date: 2006-02-23 10:27:43 -0500 (Thu, 23 Feb 2006) $ Norman Walsh 2006 Norman Walsh Yesterday, the question was XHTML™ Modularization 1.1, today it's SAX. Apropos of the question “how many changes can be introduced into a document without subjecting it to technical review”, can I make a really, really small change to SAX? The problem is the following bug report:
SAXException can take a nested exception, but it doesn't implement the getCause method, so it doesn't participate in the exception nesting mechanism introduced in JDK 1.4. Because of this, when one prints out "e.printStackTrace()", it doesn't show exceptions nested inside SAXException.
The proposed fix is straightforward, simply add: public Throwable getCause() { return exception; } to org.xml.sax.SAXException. I don't believe that this introduces any compatibility problems. Under JDK 1.4 and beyond, getCause is already inherited from Throwable and I don't think the extra method will cause any problems under JDK 1.3 and earlier (but I could be wrong about that, I haven't really investigated it and I don't claim to be a master of JDK compatibility rules by any means). That said, as the specification lead for JAXP, I'm very reluctant to introduce any changes into the endorsed API, no matter how small, without community support. The submitter opines, “I understand the hesitation. On the other hand, people are wasting their time because we don't have these three lines.” I understand that too. At least there's somewhere I can ask. I have exactly the same problem with another specification, except without that luxury. I just hope consensus builds quickly because the window for making this change for JAXP 1.4 is really, really small.