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nkuebelbeck
nkuebelbeck

Reputation: 283

java xml retrieve named parameter

<root>
<program name="SomeProgramName">
    <params>
        <param name='name'>test</param>
        <param name='name2'>test2</param>
    </params>
</program>
</root>

I have the above xml doc. I need to change the value of test to a new value

I read in the xml doc as 

String xmlfile = "path\\to\\file.xml"
DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
Document doc = docBuilder.parse(xmlfile);

//get the params element
Node params = doc.getElementsByTagName("params").item(0);

//get a list of nodes in the params element
NodeList param = params.getChildNodes();

This is where I am stuck. I can't find a method to set the value of one of the param elements by the "name"

I'm using java 1.7

Upvotes: 1

Views: 1015

Answers (2)

sevensevens
sevensevens

Reputation: 1750

You'll need to type each Node to type Element to be able to set the text and attributes. You might want to look at XPath, which simplifies things like this.

import javax.xml.parsers.*;
import javax.xml.xpath.*;
import org.w3c.dom.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        String xmlfile = "src/forum17753835/file.xml";
        DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
        Document doc = docBuilder.parse(xmlfile);

        XPathFactory xpathFactory = XPathFactory.newInstance();
        XPath xpath = xpathFactory.newXPath();
        Element element = (Element) xpath.evaluate("/root/program/params/param[@name='name2']", doc, XPathConstants.NODE);
        System.out.println(element.getTextContent());
    }

}

Upvotes: 3

Ilya
Ilya

Reputation: 29693

  NodeList params = doc.getElementsByTagName("param");
  for (int i = 0; i < params.getLength(); i++)
  {
     if (params.item(i).getAttributes().getNamedItem("name").getNodeValue().equals("name2"))
     {
        // do smth with element <param name='name2'>test2</param>
        // that is params.item(i) in current context
     }
  }

Upvotes: 0

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