asked on

parsing XML files with DOM problem

Hi,

I'm trying to parse a simple XML document like this:
<policy>
<portnum>60000</portnum>
<check name="1">
etc..

So, when I do: (using getNthElement() method which simply does root.getElementsByTagName("portnum"))
root = document.getDocumentElement();

Element pPort = this.getNthElement(root, "portnum", 0);
Node pPortText = pPort.getFirstChild();
portNumber = new Integer(pPortText.getNodeValue()).intValue();

I can get the port number without a problem. Actually, by using the getElementsByTagName() method I can access any Element in the XML tree, and reach their child TEXT nodes.

However, when I try the following:

Node myroot = document.getFirstChild();
Node portNumNode = myroot.getFirstChild();
System.out.println("root name: "+myroot.getNodeName());
System.out.println("Num node: " + portNumNode.getNodeName());

I get the result:
root name: policy
Num node: #text

I also did some other tries, but it seems that I can never make my way around the XML tree by using these getFirstChild() methods. What could be the problem?

nir2002

Hi,

change the code to the code below and you will get what you want?

Node myroot = document.getFirstChild();
Node portNumNode = myroot.getFirstChild();
System.out.println("root name: "+myroot.getNodeName());
System.out.println("Num node: " + portNumNode.getNodeValue());

You use the API worng. I suggest you use JDOM Element API.
According to the API if you ad the name of node of type Text you get "#text"
if the node is an element (for eg a node that have other nodes) this method retun the tag name of the element.

Best regards
Nir

CEHJ

Listening..

kushcu

ASKER

In that case, I get the following output:
root name: policy
Num node:

(an empty field.)

CEHJ

What happens when you do

>>System.out.println("Num node name: " + portNumNode.getNodeName());

?

ASKER CERTIFIED SOLUTION

nir2002

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

kushcu

ASKER

CEHJ, please check my original posting.

nir2002, it prints:
root name: policy
Num node: portnum.

could you explain me why that is so?

kushcu

ASKER

btw, I guess your code fragment fully solves my original problem. thanks.

nir2002

:-)
I don't use the API in this way.
It more like the way in your beginning of you question

>>So, when I do: (using getNthElement() method which >>simply does root.getElementsByTagName("portnum"))
>>root = document.getDocumentElement();

>>Element pPort = this.getNthElement(root, "portnum", 0);
>>Node pPortText = pPort.getFirstChild();
>>portNumber = new Integer(pPortText.getNodeValue()).intValue();

>>I can get the port number without a problem. Actually, by using the getElementsByTagName() method I can access any Element in the XML tree, and reach their child TEXT nodes.

Well, it is probably a matter of taste.

For your question, Although it may seem odd but when you build your dom, before the portnum node, there was a text node. the getNextSibling() function bring us the next node skipping it. since it is a element the getNodeName() bring is tag name portnum.

Best regards
Nir