XML pretty-printing in Java

Suppose there is a String with XML file content in it

String xmlStr= "<error><error-id>1</error-id><error-name>ERR-ONE</error-one></error>";

When the xmlStr is printed using Java streams, it prints in a single line sans formatting and indentation.

To get it ‘pretty-printed’, javax XML API library can be used.

Source xmlInput = new StreamSource(new StringReader(xml)); 
StreamResult xmlOutput = new StreamResult(new StringWriter()); 
Transformer transformer = TransformerFactory.newInstance().newTransformer();  
//transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, "testing.dtd"); 
transformer.setOutputProperty(OutputKeys.INDENT, "yes"); 
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2"); 
transformer.transform(xmlInput, xmlOutput); 
xml=xmlOutput.getWriter().toString(); 
System.out.println("THE RESULT XML "+xml); 

• Java and XML 
• Java & XML for Dummies