How to retrieve element value of XML using Java?

Question

I am new to XML. I want to read the following XML on the basis of request name. Please help me on how to read the below XML in Java -

<?xml version="1.0"?>     <config>         <Request name="ValidateEmailRequest">             <requestqueue>emailrequest</requestqueue>             <responsequeue>emailresponse</responsequeue>         </Request>         <Request name="CleanEmail">             <requestqueue>Cleanrequest</requestqueue>             <responsequeue>Cleanresponse</responsequeue>         </Request>     </config> 

Answer 1

If your XML is a String, Then you can do the following:

String xml = ""; //Populated XML String....  DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new InputSource(new StringReader(xml))); Element rootElement = document.getDocumentElement(); 

If your XML is in a file, then Document document will be instantiated like this:

Document document = builder.parse(new File("file.xml")); 

The document.getDocumentElement() returns you the node that is the document element of the document (in your case <config>).

Once you have a rootElement, you can access the element's attribute (by calling rootElement.getAttribute() method), etc. For more methods on java's org.w3c.dom.Element

More info on java DocumentBuilder & DocumentBuilderFactory. Bear in mind, the example provided creates a XML DOM tree so if you have a huge XML data, the tree can be huge.

• Related question.

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Update Here's an example to get "value" of element <requestqueue>

protected String getString(String tagName, Element element) {         NodeList list = element.getElementsByTagName(tagName);         if (list != null && list.getLength() > 0) {             NodeList subList = list.item(0).getChildNodes();              if (subList != null && subList.getLength() > 0) {                 return subList.item(0).getNodeValue();             }         }          return null;     } 

You can effectively call it as,

String requestQueueName = getString("requestqueue", element);