D-Net

package eu.dnetlib.enabling.tools; // NOPMD

import java.io.IOException;

import java.io.InputStream;

import java.io.StringWriter;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.TransformerFactory;

import javax.xml.xpath.XPathExpressionException;

import org.apache.commons.io.IOUtils;

import org.xml.sax.SAXException;

/**

 * implements a possibly optimized OpaqueResource constructed from a stream containing the xml source.

 * 

 * <p>the optimization consists of postponing the parsing as possibly and parse the profile passing the stream

 * directly to the xml parser.<p>

 * 

 * <p>

 * TODO: implement the optimization, currenly converts to string and reuses StringOpaqueResource

 * </p>

 * 

 * @author marko

 *

 */

public class StreamOpaqueResource extends StringOpaqueResource {

	/**

	 * construct with an input stream.

	 * 

	 * @param source source stream of xml text

	 * @throws XPathExpressionException shouldn't happen

	 * @throws SAXException could happen

	 * @throws IOException could happen

	 * @throws ParserConfigurationException shouldn't happen

	 */

	public StreamOpaqueResource(final InputStream source, final TransformerFactory tf) throws XPathExpressionException, SAXException, IOException, ParserConfigurationException {

		super(stringify(source), tf);

	}

	/**

	 * helper method: reads a stream to a string.

	 * 

	 * @param source input stream

	 * @return string containing the whole stream content.

	 * @throws IOException could happen.

	 */

	private static String stringify(final InputStream source) throws IOException {

		final StringWriter writer = new StringWriter();

		IOUtils.copy(source, writer);

		return writer.getBuffer().toString();

	}

}