Java: How to Indent XML Generated by Transformer

Neither of the suggested solutions worked for me. So I kept on searching for an alternative solution, which ended up being a mixture of the two before mentioned and a third step.

1. set the indent-number into the transformerfactory
2. enable the indent in the transformer
3. wrap the otuputstream with a writer (or bufferedwriter)

//(1)
TransformerFactory tf = TransformerFactory.newInstance();
tf.setAttribute("indent-number", new Integer(2));

//(2)
Transformer t = tf.newTransformer();
t.setOutputProperty(OutputKeys.INDENT, "yes");

//(3)
t.transform(new DOMSource(doc),
new StreamResult(new OutputStreamWriter(out, "utf-8"));

You must do (3) to workaround a "buggy" behavior of the xml handling code.

Source: johnnymac75 @ http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6296446

(If I have cited my source incorrectly please let me know)

You need to enable 'INDENT' and set the indent amount for the transformer:

t.setOutputProperty(OutputKeys.INDENT, "yes");
t.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");

Update:

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Reference : How to strip whitespace-only text nodes from a DOM before serialization?

(Many thanks to all members especially @marc-novakowski, @james-murty and @saad):