StylesheetTransformation.java

package de.jos.labelgenerator.pdf;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

import org.apache.commons.io.IOUtils;

import de.jos.labelgenerator.components.button.ButtonLabel;
import de.jos.labelgenerator.configuration.Layout;
import de.jos.labelgenerator.configuration.addressProvider.MockAddress;
import de.jos.labelgenerator.configuration.addressProvider.MockAddress2;
import de.jos.labelgenerator.template.TemplatingEngine;

public class StylesheetTransformation {

	private static final Logger LOGGER = Logger.getLogger(StylesheetTransformation.class.getName());

	private static final ClassLoader classLoader = StylesheetTransformation.class.getClassLoader();

	private static final String XSLT_FILENAME = "xslt/replacement_template.xsl";

	private static final String TEMPLATE_TO_MAKE_DYNAMIC = "layouts/odt/template.xml";

	private TemplatingEngine templateEngine = new TemplatingEngine();

	public StylesheetTransformation() {
	}

	/**
	 * Returns the generated updated content.xml file after the stylesheet
	 * transformation. Returns null if an error occured.
	 * 
	 * @param layout
	 * @param buttonLabelList
	 * @return
	 * @throws Exception
	 */
	public String generate(Layout layout, List<ButtonLabel> buttonLabelList) throws Exception {

		LOGGER.log(Level.INFO, "Performing Stylesheet tranformation.");

		// read the xslt file
		final String originalStylesheet = readFileFromResourceInString(XSLT_FILENAME);
		final String originalTemplate = readFileFromResourceInString(TEMPLATE_TO_MAKE_DYNAMIC);

		final TransformerFactory transformerFactory = TransformerFactory.newInstance();

		String workingTemplate = originalTemplate;
		// now start applying the velocity placeholders for each address
		for (ButtonLabel tmpButtonLabel : buttonLabelList) {

			// replace address, frameNumber, leadingBlanks
			final String renderedXslt = templateEngine.renderXsltTempalte(tmpButtonLabel.getAddress(),
					originalStylesheet, tmpButtonLabel.getIndex());

			final Transformer transformer = transformerFactory.newTransformer(new StreamSource(
					new ByteArrayInputStream(renderedXslt.getBytes())));

			// perform stylesheet transformation
			final ByteArrayOutputStream bout = new ByteArrayOutputStream();
			transformer.transform(new StreamSource(new ByteArrayInputStream(workingTemplate.getBytes())),
					new StreamResult(bout));
			workingTemplate = bout.toString("UTF-8");
		}

		System.out.println(workingTemplate);

		return workingTemplate;
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {

		List<ButtonLabel> buttonLabels = new ArrayList<ButtonLabel>();
		ButtonLabel buttonLabel = new ButtonLabel(4);
		buttonLabel.setAddress(new MockAddress2());

		buttonLabels.add(buttonLabel);

		buttonLabel = new ButtonLabel(2);
		buttonLabel.setAddress(new MockAddress());

		buttonLabels.add(buttonLabel);

		StylesheetTransformation transformation = new StylesheetTransformation();
		transformation.generate(null, buttonLabels);
	}

	/**
	 * TODO move to file utils.
	 * 
	 * Read content from a file and put it into a String.
	 * 
	 * @param fileName
	 * @return
	 * @throws IOException
	 */
	private String readFileFromResourceInString(String fileName) throws IOException {
		final InputStream inputStream = classLoader.getResourceAsStream(fileName);
		return IOUtils.toString(inputStream);
	}

}