Thread: XML get/set node by attribute value

Hello community,

I've seen several posts regarding XML processing with Java, however none that I've found address my current problem.

I've developed an XMLFileHandler class that loads a given xml file into a Document object, and supports some basic methods such as getRootElement(), getChildNode(), getChildNodes(), getNodeAttributeValue(), etc., etc., etc....

This behaviour has been sufficient enough for accessing nodes/values/attributes in the XML document, but my client has now added a requirement to enable editing of some of these values within the XML document.

I've tried (and failed) at developing a method to do this. The XML file is in the following format:

<?xml version="1.0" encoding="UTF-8" ?>
<locations>
   <location id="1" name="location_name">
      <a>some text</a>
      <b>some other text</b>
   </location>
   ...
   ...
   ...
</locations>

Where the attributes 'id' AND 'name' can (each) uniquely identify EVERY 'location' node.
So, the required functionality would be to design a method that can get a 'location' node by a given 'location_name' attribute value, and then set both the 'a' and 'b' sub-node values, and save the changes to the XML file.

Any suggestions or pointers would be great!
Thanks for your help in advance.
Cheers.

I was able to solve this using XPath:

1) evaluate an XPath statement that returns the node in question ("//location[@name='value']")
2) iterate the returned NodeList object to access the nodes 'ID' attribute (must be defined as ID in referenced .dtd)
3) Element location = document.getElementById( id_from_above_step );
4) iterate the 'location' element's child nodes
5) if the node name is equal to that I'm searching for, .setTextContent( "some_new_value" );
6) save changes to file via Transformer object

Hoping this may help others in the future.
Cheers