[Java] How to Indent XML Generated by Transformer

● Not Indent

1	<?xml version="1.0" encoding="UTF-8" standalone="no"?><a><b/></a>

● Indent

1 2 3 4

<?xml version="1.0" encoding="UTF-8" standalone="no"?> <a> <b/> </a>

◎ Java Code

1 2	transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2")