transform xml with an xslt in java

TransformXml.java

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.StringWriter;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

public class TransformXml {

    public static void main(String[] args) {
		transformXml("style.xslt", "source.xml", "result.xml");
	}

	private static void transformXml(String xslt, String sourceXml, String resultXml) {
		try {
			System.out.format("xslt = %s, sourceXml = %s, resultXml = %s\n", xslt, sourceXml, resultXml);
			TransformerFactory tFactory = TransformerFactory.newInstance();
			Transformer transformer = tFactory.newTransformer(new StreamSource(xslt));
			transformer.setOutputProperty(OutputKeys.INDENT, "yes");
			transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
			// (unnecessary) transformer.setOutputProperty("{http://xml.apache.org/xalan}indent-amount", "4");
			transformer.setOutputProperty("{http://saxon.sf.net/}indent-spaces", "4");
			transformer.transform(new StreamSource(sourceXml), new StreamResult(new FileOutputStream(resultXml)));
		} catch (Throwable t) {
			t.printStackTrace();
		}
	}

	public static void encodeXmlAsAscii(String sourceXml, String resultXml) {
		try {
			TransformerFactory tFactory = TransformerFactory.newInstance();
			Transformer transformer = tFactory.newTransformer();
			transformer.setOutputProperty(OutputKeys.INDENT, "yes");
			transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
			transformer.setOutputProperty(OutputKeys.ENCODING, "US-ASCII");
			transformer.transform(new StreamSource(sourceXml), new StreamResult(new BufferedOutputStream(new FileOutputStream(resultXml))));
		} catch (Throwable t) {
			t.printStackTrace();
		}
	}

	public static Document readXmlFromClassPath(String fileName) throws Exception {
		try (InputStream in = TransformXml.class.getResourceAsStream(fileName);) {
			return DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(in);
		}
	}
	
	public static String xmlDocumentToString(Document doc) throws Exception {
		StringWriter writer = new StringWriter();
		Transformer transformer = TransformerFactory.newInstance().newTransformer();
		transformer.setOutputProperty(OutputKeys.INDENT, "yes");
		transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
		transformer.transform(new DOMSource(doc), new StreamResult(writer));
		return writer.toString();
	}
}