html2pdf.java

使用fop进行html到PDF文件的生成

import java.io.FileInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.io.ByteArrayOutputStream;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;

import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;

import org.w3c.tidy.Tidy;
import org.w3c.dom.Document;

import org.xml.sax.InputSource;

import org.apache.fop.apps.Driver;
import org.apache.fop.messaging.MessageHandler;
import org.apache.fop.tools.DocumentInputSource;

import org.apache.avalon.framework.logger.ConsoleLogger;
import org.apache.avalon.framework.logger.Logger;

/*
 *  Class that converts HTML to PDF using
 *  the DOM interfaces of JTidy, Xalan, and FOP.
 *
 *  @author N. Afshartous
 * 
 */
public class Html2Pdf {


    public static void main(String[] args) {

	// open file
	if (args.length != 2) {
	    System.out.println("Usage: Html2Pdf htmlFile styleSheet");
	    System.exit(1);
	}

	FileInputStream input = null;
	String htmlFileName = args[0];
	
	try {
		
		input = new FileInputStream(htmlFileName);
	
	}
	catch (java.io.FileNotFoundException e) {
		System.out.println("File not found: " + htmlFileName);
	}

        Tidy tidy = new Tidy();
	Document xmlDoc = tidy.parseDOM(input, null);
	
	Document foDoc = xml2FO(xmlDoc, args[1]);

	String pdfFileName = htmlFileName.substring(0, htmlFileName.indexOf(".")) + ".pdf";
	try {
	    OutputStream pdf = new FileOutputStream(new File(pdfFileName));
	    pdf.write(fo2PDF(foDoc));
	}
	catch (java.io.FileNotFoundException e) {
	    System.out.println("Error creating PDF: " + pdfFileName);
	}
	catch (java.io.IOException e) {
	    System.out.println("Error writing PDF: " + pdfFileName);
	}

	
    }


    /*
     *  Applies stylesheet to input.
     *
     *  @param xml  The xml input Document
     *  
     *  @param stylesheet Name of the stylesheet
     *
     *  @return Document  Result of the transform
     */
    private static Document xml2FO(Document xml, String styleSheet) {

	DOMSource xmlDomSource = new DOMSource(xml);
      	DOMResult domResult = new DOMResult();

	Transformer transformer = getTransformer(styleSheet);
	
	if (transformer == null) {
	    System.out.println("Error creating transformer for " + styleSheet);
	    System.exit(1);
	}
	try {
	    transformer.transform(xmlDomSource, domResult);
	}
	catch (javax.xml.transform.TransformerException e) {
	    return null;
	}
	return (Document) domResult.getNode();

    }


    /*
     *  Apply FOP to XSL-FO input
     *
     *  @param foDocument  The XSL-FO input
     *  
     *  @return byte[]  PDF result
     */
    private static byte[] fo2PDF(Document foDocument) {

        DocumentInputSource fopInputSource = new DocumentInputSource(
                                                         foDocument);

        try {

            ByteArrayOutputStream out = new ByteArrayOutputStream();
            Logger log = new ConsoleLogger(ConsoleLogger.LEVEL_WARN);

            Driver driver = new Driver(fopInputSource, out);
            driver.setLogger(log);
            driver.setRenderer(Driver.RENDER_PDF);
            driver.run();

            return out.toByteArray();

        } catch (Exception ex) {
            return null;
        }
    }


    /*
     *  Create and return a Transformer for the specified stylesheet.
     *  
     *  Based on the DOM2DOM.java example in the Xalan distribution.
     */
    private static Transformer getTransformer(String styleSheet) {

	try {

	    TransformerFactory tFactory = TransformerFactory.newInstance();

	    DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();

	    dFactory.setNamespaceAware(true);
      
	    DocumentBuilder dBuilder = dFactory.newDocumentBuilder();
	    Document xslDoc = dBuilder.parse(styleSheet);
	    DOMSource xslDomSource = new DOMSource(xslDoc);

	    return tFactory.newTransformer(xslDomSource);

	}
	catch (javax.xml.transform.TransformerException e) {
	    e.printStackTrace();
	    return null;
	}
	catch (java.io.IOException e) {
	    e.printStackTrace();
	    return null;
	}
	catch (javax.xml.parsers.ParserConfigurationException e) {
	    e.printStackTrace();
	    return null;
	}
	catch (org.xml.sax.SAXException e) {	
	    e.printStackTrace();
	    return null;
	}

    }

}