java xml retrieve named parameter

Question

<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

I suggest using an XPath query on it. Syntax would be something like /root/program/params/param[@name='name2']. See this question for the xpath setup — Gus
– Gus, Commented Jul 19, 2013 at 19:24

bdoughan · Accepted Answer · 2013-07-20 11:01:06Z

3

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());
    }

}

edited Jul 20, 2013 at 11:01

bdoughan

149k25 gold badges309 silver badges411 bronze badges

answered Jul 19, 2013 at 19:31

sevensevens

1,74816 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

nkuebelbeck Over a year ago

xpath looks interesting. I will look into this solution

Ilya · Accepted Answer · 2013-07-19 19:36:19Z

0

  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
     }
  }

answered Jul 19, 2013 at 19:36

Ilya

29.9k19 gold badges119 silver badges161 bronze badges

Collectives™ on Stack Overflow

java xml retrieve named parameter

2 Answers 2

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related