XML -> DOM -> Modify -> String

Question

I am coding an Android client that talks to some web services via XML packets. A typical packet looks like this..

<Packet service="login">
  <username></username>
  <password></password>
</Packet>

I have about 20 of these packets and would like to store them in my resources maybe in res/xml or res/raw

I want to store these 'empty' packets and load them using XML DOM and then fill in the content between the tags or attributes but am unsure how to do this.

Once the DOM packet has been filled in I want to get that back as a String so that I can send the packet to the server.

So to summarize my questions are..

(1) How do I load an XML resource using DOM?

(2) How do I convert the DOM object to a String?

Answer 1

Conversion from xml to DOM is done by a XML Parser, common helper libraries are jdom or dom4j. You feed a stream to the parser and the result is (if the xml is OK) a DOM document.

The other way round is done with a XMLOutputter. That's basically a writer which takes a DOM document (or a node) and writes xml to a stream. jdom and dom4j both contain such a writer.

Use ByteArrayInputStream and ByteArrayOutputStream to convert between streams and String.

Answer 2

You can use the javax.xml.parsers.*, org.xml.sax.*, org.w3c.dom.*, org.xmlpull.v1.* packages for full XML support on Android. Here's a tutorial: http://www.ibm.com/developerworks/opensource/library/x-android/index.html