src/java/org/apache/fop/servlet/FopServlet.java - xmlgraphics-fop - Git at Google

 /*
  * Copyright 1999-2004 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.
  */

 /* $Id$ */

 package org.apache.fop.servlet;

 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.PrintWriter;

 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.xml.transform.Result;
 import javax.xml.transform.Source;
 import javax.xml.transform.Transformer;
 import javax.xml.transform.TransformerException;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.sax.SAXResult;
 import javax.xml.transform.stream.StreamSource;

 import org.apache.commons.logging.impl.SimpleLog;

 //FOP
 import org.apache.fop.apps.Fop;
 import org.apache.fop.apps.FOPException;

 /**
  * Example servlet to generate a PDF from a servlet.
  * <br/>
  * 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/FopServlet?fo=readme.fo
  * <br/>
  * Example URL: http://servername/fop/servlet/FopServlet?xml=data.xml&xslt=format.xsl
  * <br/>
  * For this to work with Internet Explorer, you might need to append "&ext=.pdf"
  * to the URL.
  *
  * @author <a href="mailto:fop-dev@xml.apache.org">Apache XML FOP Development Team</a>
  * @version $Id: FopServlet.java,v 1.2 2003/03/07 09:48:05 jeremias Exp $
  * (todo) Ev. add caching mechanism for Templates objects
  */
 public class FopServlet 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/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 {
         try {
             //Get parameters
             String foParam = request.getParameter(FO_REQUEST_PARAM);
             String xmlParam = request.getParameter(XML_REQUEST_PARAM);
             String xsltParam = request.getParameter(XSLT_REQUEST_PARAM);

             //Analyze parameters and decide with method to use
             byte[] content = null;
             if (foParam != null) {
                 content = renderFO(foParam);
             } else if ((xmlParam != null) && (xsltParam != null)) {
                 content = renderXML(xmlParam, xsltParam);
             } else {
                 PrintWriter out = response.getWriter();
                 out.println("<html><head><title>Error</title></head>\n"
                           + "<body><h1>FopServlet Error</h1><h3>No 'fo' "
                           + "request param given.</body></html>");
             }

             if (content != null) {
                 //Send the result back to the client
                 response.setContentType("application/pdf");
                 response.setContentLength(content.length);
                 response.getOutputStream().write(content);
                 response.getOutputStream().flush();
             }

         } catch (Exception ex) {
             throw new ServletException(ex);
         }
     }

     /**
      * Converts a String parameter to a JAXP Source object.
      * @param param a String parameter
      * @return Source the generated Source object
      */
     protected Source convertString2Source(String param) {
         return new StreamSource(new File(param));
     }

     /**
      * Renders an XSL-FO file into a PDF file. The PDF is written to a byte
      * array that is returned as the method's result.
      * @param fo the XSL-FO file
      * @return byte[] the rendered PDF file
      * @throws FOPException If an error occurs during the rendering of the
      * XSL-FO
      * @throws TransformerException If an error occurs while parsing the input
      * file
      */
     protected byte[] renderFO(String fo)
                 throws FOPException, TransformerException {

         //Setup source
         Source foSrc = convertString2Source(fo);

         //Setup the identity transformation
         Transformer transformer = this.transFactory.newTransformer();

         //Start transformation and rendering process
         return render(foSrc, transformer);
     }

     /**
      * Renders an XML file into a PDF file by applying a stylesheet
      * that converts the XML to XSL-FO. The PDF is written to a byte array
      * that is returned as the method's result.
      * @param xml the XML file
      * @param xslt the XSLT file
      * @return byte[] the rendered PDF file
      * @throws FOPException If an error occurs during the rendering of the
      * XSL-FO
      * @throws TransformerException If an error occurs during XSL
      * transformation
      */
     protected byte[] renderXML(String xml, String xslt)
                 throws FOPException, TransformerException {

         //Setup sources
         Source xmlSrc = convertString2Source(xml);
         Source xsltSrc = convertString2Source(xslt);

         //Setup the XSL transformation
         Transformer transformer = this.transFactory.newTransformer(xsltSrc);

         //Start transformation and rendering process
         return render(xmlSrc, transformer);
     }

     /**
      * Renders an input file (XML or XSL-FO) into a PDF file. It uses the JAXP
      * transformer given to optionally transform the input document to XSL-FO.
      * The transformer may be an identity transformer in which case the input
      * must already be XSL-FO. The PDF is written to a byte array that is
      * returned as the method's result.
      * @param src Input XML or XSL-FO
      * @param transformer Transformer to use for optional transformation
      * @return byte[] the rendered PDF file
      * @throws FOPException If an error occurs during the rendering of the
      * XSL-FO
      * @throws TransformerException If an error occurs during XSL
      * transformation
      */
     protected byte[] render(Source src, Transformer transformer)
                 throws FOPException, TransformerException {

         //Setup FOP
         Fop fop = new Fop(Fop.RENDER_PDF);

         //Setup output
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         fop.setOutputStream(out);

         //Make sure the XSL transformation's result is piped through to FOP
         Result res = new SAXResult(fop.getDefaultHandler());

         //Start the transformation and rendering process
         transformer.transform(src, res);

         //Return the result
         return out.toByteArray();
     }

 }
	/*
	* Copyright 1999-2004 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.
	*/

	/* $Id$ */

	package org.apache.fop.servlet;

	import java.io.ByteArrayOutputStream;
	import java.io.File;
	import java.io.PrintWriter;

	import javax.servlet.ServletException;
	import javax.servlet.http.HttpServlet;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;
	import javax.xml.transform.Result;
	import javax.xml.transform.Source;
	import javax.xml.transform.Transformer;
	import javax.xml.transform.TransformerException;
	import javax.xml.transform.TransformerFactory;
	import javax.xml.transform.sax.SAXResult;
	import javax.xml.transform.stream.StreamSource;

	import org.apache.commons.logging.impl.SimpleLog;

	//FOP
	import org.apache.fop.apps.Fop;
	import org.apache.fop.apps.FOPException;

	/**
	* Example servlet to generate a PDF from a servlet.
	* <br/>
	* 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/FopServlet?fo=readme.fo
	* <br/>
	* Example URL: http://servername/fop/servlet/FopServlet?xml=data.xml&xslt=format.xsl
	* <br/>
	* For this to work with Internet Explorer, you might need to append "&ext=.pdf"
	* to the URL.
	*
	* @author <a href="mailto:fop-dev@xml.apache.org">Apache XML FOP Development Team</a>
	* @version $Id: FopServlet.java,v 1.2 2003/03/07 09:48:05 jeremias Exp $
	* (todo) Ev. add caching mechanism for Templates objects
	*/
	public class FopServlet 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/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 {
	try {
	//Get parameters
	String foParam = request.getParameter(FO_REQUEST_PARAM);
	String xmlParam = request.getParameter(XML_REQUEST_PARAM);
	String xsltParam = request.getParameter(XSLT_REQUEST_PARAM);

	//Analyze parameters and decide with method to use
	byte[] content = null;
	if (foParam != null) {
	content = renderFO(foParam);
	} else if ((xmlParam != null) && (xsltParam != null)) {
	content = renderXML(xmlParam, xsltParam);
	} else {
	PrintWriter out = response.getWriter();
	out.println("<html><head><title>Error</title></head>\n"
	+ "<body><h1>FopServlet Error</h1><h3>No 'fo' "
	+ "request param given.</body></html>");
	}

	if (content != null) {
	//Send the result back to the client
	response.setContentType("application/pdf");
	response.setContentLength(content.length);
	response.getOutputStream().write(content);
	response.getOutputStream().flush();
	}

	} catch (Exception ex) {
	throw new ServletException(ex);
	}
	}

	/**
	* Converts a String parameter to a JAXP Source object.
	* @param param a String parameter
	* @return Source the generated Source object
	*/
	protected Source convertString2Source(String param) {
	return new StreamSource(new File(param));
	}

	/**
	* Renders an XSL-FO file into a PDF file. The PDF is written to a byte
	* array that is returned as the method's result.
	* @param fo the XSL-FO file
	* @return byte[] the rendered PDF file
	* @throws FOPException If an error occurs during the rendering of the
	* XSL-FO
	* @throws TransformerException If an error occurs while parsing the input
	* file
	*/
	protected byte[] renderFO(String fo)
	throws FOPException, TransformerException {

	//Setup source
	Source foSrc = convertString2Source(fo);

	//Setup the identity transformation
	Transformer transformer = this.transFactory.newTransformer();

	//Start transformation and rendering process
	return render(foSrc, transformer);
	}

	/**
	* Renders an XML file into a PDF file by applying a stylesheet
	* that converts the XML to XSL-FO. The PDF is written to a byte array
	* that is returned as the method's result.
	* @param xml the XML file
	* @param xslt the XSLT file
	* @return byte[] the rendered PDF file
	* @throws FOPException If an error occurs during the rendering of the
	* XSL-FO
	* @throws TransformerException If an error occurs during XSL
	* transformation
	*/
	protected byte[] renderXML(String xml, String xslt)
	throws FOPException, TransformerException {

	//Setup sources
	Source xmlSrc = convertString2Source(xml);
	Source xsltSrc = convertString2Source(xslt);

	//Setup the XSL transformation
	Transformer transformer = this.transFactory.newTransformer(xsltSrc);

	//Start transformation and rendering process
	return render(xmlSrc, transformer);
	}

	/**
	* Renders an input file (XML or XSL-FO) into a PDF file. It uses the JAXP
	* transformer given to optionally transform the input document to XSL-FO.
	* The transformer may be an identity transformer in which case the input
	* must already be XSL-FO. The PDF is written to a byte array that is
	* returned as the method's result.
	* @param src Input XML or XSL-FO
	* @param transformer Transformer to use for optional transformation
	* @return byte[] the rendered PDF file
	* @throws FOPException If an error occurs during the rendering of the
	* XSL-FO
	* @throws TransformerException If an error occurs during XSL
	* transformation
	*/
	protected byte[] render(Source src, Transformer transformer)
	throws FOPException, TransformerException {

	//Setup FOP
	Fop fop = new Fop(Fop.RENDER_PDF);

	//Setup output
	ByteArrayOutputStream out = new ByteArrayOutputStream();
	fop.setOutputStream(out);

	//Make sure the XSL transformation's result is piped through to FOP
	Result res = new SAXResult(fop.getDefaultHandler());

	//Start the transformation and rendering process
	transformer.transform(src, res);

	//Return the result
	return out.toByteArray();
	}

	}