/*
* Copyright 1999-2005 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id: FopPrintServlet.java 332791 2005-11-12 15:58:07Z jeremias $ */
package org.apache.fop.servlet;
import java.io.File;
import java.io.InputStream;
import java.io.PrintWriter;
// JAXP
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.stream.StreamSource;
// XML
import org.apache.commons.logging.impl.SimpleLog;
import org.apache.fop.apps.Fop;
import org.apache.fop.apps.MimeConstants;
/**
* Example servlet to generate a fop printout from a servlet.
* Printing goes to the default printer on host where the servlet executes.
* Servlet param is:
* <ul>
* <li>fo: the path to a XSL-FO file to render
* </ul>
* or
* <ul>
* <li>xml: the path to an XML file to render</li>
* <li>xslt: the path to an XSLT file that can transform the above XML to XSL-FO</li>
* </ul>
* <br/>
* Example URL: http://servername/fop/servlet/FopPrintServlet?fo=readme.fo
* <br/>
* Example URL: http://servername/fop/servlet/FopPrintServlet?xml=data.xml&xsl=format.xsl
*
* @author <a href="mailto:fop-dev@xml.apache.org">Apache XML FOP Development Team</a>
* @version $Id: FopPrintServlet.java 332791 2005-11-12 15:58:07Z jeremias $
* (todo) Doesn't work since there's no AWTRenderer at the moment. Revisit when
* available.
* (todo) Ev. add caching mechanism for Templates objects
*/
public class FopPrintServlet extends HttpServlet {
/** Name of the parameter used for the XSL-FO file */
protected static final String FO_REQUEST_PARAM = "fo";
/** Name of the parameter used for the XML file */
protected static final String XML_REQUEST_PARAM = "xml";
/** Name of the parameter used for the XSLT file */
protected static final String XSLT_REQUEST_PARAM = "xslt";
/** Logger to give to FOP */
protected SimpleLog log = null;
/** The TransformerFactory to use to create Transformer instances */
protected TransformerFactory transFactory = null;
/**
* @see javax.servlet.GenericServlet#init()
*/
public void init() throws ServletException {
this.log = new SimpleLog("FOP/Print Servlet");
log.setLevel(SimpleLog.LOG_LEVEL_WARN);
this.transFactory = TransformerFactory.newInstance();
}
/**
* @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest, HttpServletResponse)
*/
public void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException {
if (log == null) {
log = new SimpleLog("FOP/Print Servlet");
log.setLevel(SimpleLog.LOG_LEVEL_WARN);
}
try {
String foParam = request.getParameter(FO_REQUEST_PARAM);
String xmlParam = request.getParameter(XML_REQUEST_PARAM);
String xsltParam = request.getParameter(XSLT_REQUEST_PARAM);
if (foParam != null) {
InputStream file = new java.io.FileInputStream(foParam);
renderFO(file, response);
} else if ((xmlParam != null) && (xsltParam != null)) {
renderXML(new File(xmlParam), new File(xsltParam), response);
} else {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html><title>Error</title>\n"
+ "<body><h1>FopServlet Error</h1>\n"
+ "<h3>No 'fo' or 'xml/xsl' "
+ "request param given.</h3></body>\n</html>");
}
} catch (ServletException ex) {
throw ex;
} catch (Exception ex) {
throw new ServletException(ex);
}
}
/**
* Renders an FO inputsource to the default printer.
* @param foFile The XSL-FO file
* @param response Response to write to
* @throws ServletException In case of a problem
*/
public void renderFO(InputStream foFile,
HttpServletResponse response) throws ServletException {
try {
Fop fop = new Fop(MimeConstants.MIME_FOP_PRINT);
// Setup JAXP
TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer(); //identity transformer
// Setup input for XSLT transformation
Source src = new StreamSource(foFile);
// Resulting SAX events (the generated FO) must be piped through to FOP
Result res = new SAXResult(fop.getDefaultHandler());
// Start XSLT transformation and FOP processing
transformer.transform(src, res);
reportOK (response);
} catch (Exception ex) {
throw new ServletException(ex);
}
}
/**
* Renders an FO generated using an XML and a stylesheet to the default printer.
* @param xmlfile XML file object
* @param xsltfile XSLT stylesheet
* @param response HTTP response object
* @throws ServletException In case of a problem
*/
public void renderXML(File xmlfile, File xsltfile,
HttpServletResponse response) throws ServletException {
try {
Fop fop = new Fop(MimeConstants.MIME_FOP_PRINT);
// Setup XSLT
TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer(new StreamSource(xsltfile));
// Setup input for XSLT transformation
Source src = new StreamSource(xmlfile);
// Resulting SAX events (the generated FO) must be piped through to FOP
Result res = new SAXResult(fop.getDefaultHandler());
// Start XSLT transformation and FOP processing
transformer.transform(src, res);
reportOK (response);
} catch (Exception ex) {
throw new ServletException(ex);
}
}
// private helper, tell (browser) user that file printed
private void reportOK(HttpServletResponse response)
throws ServletException {
String sMsg = "<html><title>Success</title>\n"
+ "<body><h1>FopPrintServlet: </h1>"
+ "<h3>The requested data was printed</h3></body></html>";
response.setContentType("text/html");
response.setContentLength(sMsg.length());
try {
PrintWriter out = response.getWriter();
out.println(sMsg);
out.flush();
} catch (Exception ex) {
throw new ServletException(ex);
}
}
}