getChildNodes() method returning null in Servlet

[Ravi Sengodan]

Hi All,



I�m getting a peculiar problem in a java servlet program which I developed. I�ll explain it now.

I developed an application with w3c.dom parser (for parsing xml information) in java. When I execute my program as a stand alone java program, it is getting the results properly. But when I tried to integrate into a Servlet, it is not getting the proper results. Mainly the following statement (number 2) is getting problem,

1. Element root = doc.getDocumentElement();

2. String response = root.getChildNodes().toString();

In Java servets, the string variable �response� value is getting null. But if I execute the same as a normal (i.e. stand alone) java program then it is getting the results properly. I�m not getting the reason why it is getting null when I execute as a servlet program. If any body can help me in solving this then it will be a great help for me.


Thanks in advance.
[ December 17, 2005: Message edited by: Ravi Sengodan ]

[William Brogden]

One way for the response variable to end up with null is if an exception that you are not catching and displaying occurs and the code line is never executed. Since even with an empty root element you should get an empty NodeList, I bet this is what is happening.
Bill
[ December 17, 2005: Message edited by: William Brogden ]

[Paul Clapham]

You are using different versions of the XML software there. When you call toString() on a Node, some DOM implementations return the XML representation of the Node, and others return what the nodeValue() method returns. So when you see "null", you are using one of the latter implementations.

(Note from the API documentation for Node that if the Node is an Element, then nodeValue() returns null. That doesn't mean the Element is null.)

The way to make this consistent is to stop using toString() to display Nodes from a DOM, since it's undefined how toString() works on a Node and implementers are free to choose different representations.

[Ravi Sengodan]

thanks William and Paul.,

Now it is working fine. The probelem has happened because of the xml api incompatibility. Now i have corrected it....Thanks for information....

thanks,
Ravi
[ December 21, 2005: Message edited by: Ravi Sengodan ]