Strip whitespace and newlines from XML in Java

Working solution following instructions in the question's comments by @Luiggi Mendoza.

public static String trim(String input) {    BufferedReader reader = new BufferedReader(new StringReader(input));    StringBuffer result = new StringBuffer();    try {        String line;        while ( (line = reader.readLine() ) != null)            result.append(line.trim());        return result.toString();    } catch (IOException e) {        throw new RuntimeException(e);    }}

recursively traverse the document. remove any text nodes with blank content. trim any text nodes with non-blank content.

public static void trimWhitespace(Node node){    NodeList children = node.getChildNodes();    for(int i = 0; i < children.getLength(); ++i) {        Node child = children.item(i);        if(child.getNodeType() == Node.TEXT_NODE) {            child.setTextContent(child.getTextContent().trim());        }        trimWhitespace(child);    }}

As documented in an answer to another question, the relevant function would be DocumentBuilderFactory.setIgnoringElementContentWhitespace(), but - as pointed out here already - that function requires the use of a validating parser, which requires an XML schema, or some such.

Therefore, your best bet is to iterate through the Document you get from the parser, and remove all nodes of type TEXT_NODE (or those TEXT_NODEs which contain only whitespace).