getChildNodes giving unexpected result
Solution 1
That's because you have 2 TEXT_NODE
(#text
) between each child nodes.
The following included the text nodes and their corresponding values.
<object flag="complete" id="objId" version="1">
<TEXT_NODE />
<variable_value variable_id="varId">ValueGoesHere</variable_value>
<reference item_ref="2"/>
<TEXT_NODE />
</object>
This can be verified by modifying your code:
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document dom = dBuilder.parse(new ByteArrayInputStream(S.getBytes()));
NodeList collected_objects = dom.getElementsByTagName("object");
System.out.println("Number of collected objects are "
+ collected_objects.getLength());
for (int i = 0; i < collected_objects.getLength(); i++) {
Node aNode = collected_objects.item(i);
// get children of "objects"
NodeList refNodes = aNode.getChildNodes();
System.out.println("# of chidren are " + refNodes.getLength());
//
for (int x = 0; x < refNodes.getLength(); x++) {
Node n = refNodes.item(x);
System.out.println(n.getNodeType() + " = " + n.getNodeName() + "/" + n.getNodeValue());
}
// print attributes of "objects"
NamedNodeMap attributes = aNode.getAttributes();
for (int a = 0; a < attributes.getLength(); a++) {
Node theAttribute = attributes.item(a);
System.out.println(theAttribute.getNodeName() + "="
+ theAttribute.getNodeValue());
}
}
The output:
Number of collected objects are 2
# of chidren are 5
3 = #text/
1 = variable_value/null
3 = #text/
1 = reference/null
3 = #text/
flag=complete
id=objId
version=1
# of chidren are 3
3 = #text/
1 = reference/null
3 = #text/
comment=objComment
flag=complete
id=objId
version=1
Where, 3 = TEXT_NODE
and 1 = ELEMENT_NODE
.
Solution 2
Make sure you don't have whitespaces between <object> node children. Whitespaces are considered childnodes and returned as such.
Testing if
childNode.getNodeType() == Node.ELEMENT_NODE
should be enough.
Solution 3
You are only counting ELEMENT node types. You can change your code to include the below check if you are interested in only child elements
if (aNode.getNodeType() == Node.ELEMENT_NODE)
{
...
}
user837208
Updated on July 16, 2022Comments
-
user837208 almost 2 years
My XML looks like this-
<collected_objects> <object flag="complete" id="objId" version="1"> <variable_value variable_id="varId">ValueGoesHere</variable_value> <reference item_ref="2"/> </object> <object comment="objComment" flag="complete" id="objId" version="1"> <reference item_ref="1"/> </object> </collected_objects>
I am processing it using below code-
Document dom = parser.getDocument(); NodeList collected_objects = dom.getElementsByTagName("object"); System.out.println("Number of collected objects are " + collected_objects.getLength()); for (int i = 0; i < collected_objects.getLength(); i++) { Node aNode = collected_objects.item(i); //get children of "objects" NodeList refNodes = aNode.getChildNodes(); System.out.println("# of chidren are " + refNodes.getLength()); //print attributes of "objects" NamedNodeMap attributes = aNode.getAttributes(); for (int a = 0; a < attributes.getLength(); a++) { Node theAttribute = attributes.item(a); System.out.println(theAttribute.getNodeName() + "=" + theAttribute.getNodeValue()); } }
it outputs as-
Number of collected objects are 2 # of chidren are 5 flag=complete id=objId version=1 # of chidren are 3 comment=objComment flag=complete id=objId version=1
My question is why "# of chidren are" are 5 and 3 respectively? Shouldn't I be expecting 2 and 1 respectively ? because first object has "
variable_value
" and "reference
" and second object has only "reference
"Essentially, my intent is to process children of "objects".