getElementsByTagName - failing inconsistently

Question

I am using a Java application to read an XML file and process it. The application works in the majority of cases but not in some. I have an XML doc with a list of items. The app reads the doc and compiles a list of said items as follows:

NodeList responseItemNodeList = doc.getElementsByTagName("ns:myElement")

Sometimes a list is compiled and sometimes not. I have looked at different XML docs, ones that work and ones that don't and to me, they seem identical (apart from data).

Can anyone suggest why this is occasionally failing?

EDIT: I have tried Xpath and the issue still happens.

Answer 1

You need to use the getElementsByTagName that takes a namespace parameter and a local name instead of using the prefix qualified name. Since your current code sometimes works it is probably because you are not setting setNamespaceAware(true) on the DocumentBuilderFactory.