D-Net

package eu.dnetlib.data.search.transform;

import org.apache.log4j.Logger;

import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.TransformerFactoryConfigurationError;

import javax.xml.transform.stream.StreamResult;

import javax.xml.transform.stream.StreamSource;

import java.io.StringReader;

import java.io.StringWriter;

public class XsltTransformer implements Transformer {

	private final String xslt;

	private final Logger logger = Logger.getLogger(XsltTransformer.class);

	private javax.xml.transform.Transformer xmlTransformer = null;

	private StringWriter xmlResultResource = new StringWriter();

	public XsltTransformer(String xslt) throws TransformerConfigurationException, TransformerFactoryConfigurationError {

		this.xslt = xslt;	

		//logger.debug(xslt);

		synchronized(this) {

			xmlTransformer = TransformerFactory.newInstance().newTemplates(new StreamSource(new StringReader(xslt))).newTransformer();

            xmlTransformer.setOutputProperty("encoding", "UTF-8");

		}

	}

	@Override

	public synchronized String transform(String input) throws TransformerException {

		//logger.debug("Transforming input: " + input);

		//logger.debug("xmlTransformer " + xmlTransformer);

		xmlResultResource.getBuffer().setLength(0);		

		try {

			xmlTransformer.transform(new StreamSource(new StringReader(input)), new StreamResult(xmlResultResource));

		} catch (Exception e) {

			logger.warn("Error transforming xml.", e);

			throw new TransformerException();

		}

		return xmlResultResource.getBuffer().toString();		

	}

	public String getXslt() {

		return xslt;

	}

}