Servlet moved into normal source as package org.apache.fop.servlet.

Refactored FopServlet to use JAXP instead of XSLTInputHandler.
Improved code to serve as educational example.
FopPrintServlet compiles but doesn't work because no AWT renderer is currently available.
FopServlet works fine here but currently only support filenames as input parameters. Should be improved.


git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@195920 13f79535-47bb-0310-9956-ffa450edef68

src/conf/web.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
+    "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
+<web-app>
+	<!-- Servlets -->
+  <servlet>
+    <servlet-name>Fop</servlet-name>
+    <servlet-class>org.apache.fop.servlet.FopServlet</servlet-class>
+  </servlet>
+  <servlet>
+    <servlet-name>FopPrint</servlet-name>
+    <servlet-class>org.apache.fop.servlet.FopPrintServlet</servlet-class>
+  </servlet>
+  <!-- Servlet mappings -->
+  <servlet-mapping>
+    <servlet-name>Fop</servlet-name>
+    <url-pattern>/</url-pattern>
+  </servlet-mapping>
+  <servlet-mapping>
+    <servlet-name>FopPrint</servlet-name>
+    <url-pattern>/fopprint</url-pattern>
+  </servlet-mapping>
+</web-app>

src/org/apache/fop/servlet/FopPrintServlet.java

@@ -0,0 +1,274 @@
+/*
+ * $Id$
+ * Copyright (C) 2002-2003 The Apache Software Foundation. All rights reserved.
+ * For details on use and redistribution please refer to the
+ * LICENSE file included with these sources.
+ */
+ 
+package org.apache.fop.servlet;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.PrintWriter;
+import java.util.List;
+
+import java.awt.print.PrinterJob;
+import java.awt.print.PrinterException;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.xml.transform.TransformerFactory;
+
+import org.xml.sax.InputSource;
+
+// Avalon
+import org.apache.avalon.framework.logger.ConsoleLogger;
+import org.apache.avalon.framework.logger.Logger;
+
+// FOP
+import org.apache.fop.apps.Driver;
+import org.apache.fop.apps.FOPException;
+import org.apache.fop.area.PageViewport;
+import org.apache.fop.apps.XSLTInputHandler;
+import org.apache.fop.render.awt.AWTRenderer;
+
+/**
+ * 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 $Id$
+ * @todo Doesn't work since there's no AWTRenderer at the moment. Revisit when 
+ * available.
+ * @todo Don't use XSLTInputHandler anymore
+ * @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 Logger 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 ConsoleLogger(ConsoleLogger.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 ConsoleLogger(ConsoleLogger.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(new InputSource(file), response);
+            } else if ((xmlParam != null) && (xsltParam != null)) {
+                XSLTInputHandler input =
+                  new XSLTInputHandler(new File(xmlParam),
+                                       new File(xsltParam));
+                renderXML(input, 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(InputSource foFile,
+                         HttpServletResponse response) throws ServletException {
+        try {
+            Driver driver = new Driver(foFile, null);
+            PrinterJob pj = PrinterJob.getPrinterJob();
+            PrintRenderer renderer = new PrintRenderer(pj);
+
+            driver.enableLogging(log);
+            driver.setRenderer(renderer);
+            driver.run();
+
+            reportOK (response);
+        } catch (Exception ex) {
+            throw new ServletException(ex);
+        }
+    }
+
+    /**
+     * Renders an FO generated using an XML and a stylesheet to the default printer.
+     * @param input XSLTInputHandler to use
+     * @param response Response to write to
+     * @throws ServletException In case of a problem
+     */
+    public void renderXML(XSLTInputHandler input,
+                          HttpServletResponse response) throws ServletException {
+        try {
+            Driver driver = new Driver();
+            PrinterJob pj = PrinterJob.getPrinterJob();
+            PrintRenderer renderer = new PrintRenderer(pj);
+
+            pj.setCopies(1);
+
+            driver.enableLogging(log);
+            driver.setRenderer(renderer);
+            driver.render(input.getParser(), input.getInputSource());
+
+            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);
+        }
+    }
+
+    // This is stolen from PrintStarter
+    class PrintRenderer extends AWTRenderer {
+
+        private static final int EVEN_AND_ALL = 0;
+        private static final int EVEN = 1;
+        private static final int ODD = 2;
+
+        private int startNumber;
+        private int endNumber;
+        private int mode = EVEN_AND_ALL;
+        private int copies = 1;
+        private PrinterJob printerJob;
+
+        PrintRenderer(PrinterJob printerJob) {
+            super(null);
+
+            this.printerJob = printerJob;
+            startNumber = 0 ;
+            endNumber = -1;
+
+            printerJob.setPageable(this);
+
+            mode = EVEN_AND_ALL;
+            String str = System.getProperty("even");
+            if (str != null) {
+                mode = Boolean.valueOf(str).booleanValue() ? EVEN : ODD;
+            }
+        }
+
+        public void stopRenderer() throws IOException {
+            super.stopRenderer();
+
+            if (endNumber == -1) {
+                endNumber = getPageCount();
+            }
+
+            List numbers = getInvalidPageNumbers();
+            for (int i = numbers.size() - 1; i > -1; i--) {
+                //removePage(
+                //  Integer.parseInt((String) numbers.elementAt(i)));
+            }
+            
+            try {
+                printerJob.print();
+            } catch (PrinterException e) {
+                e.printStackTrace();
+                throw new IOException("Unable to print: " 
+                                    + e.getClass().getName() + ": " + e.getMessage());
+            }
+        }
+
+        public void renderPage(PageViewport page) throws IOException, FOPException {
+            pageWidth = (int)((float) page.getViewArea().getWidth() / 1000f);
+            pageHeight = (int)((float) page.getViewArea().getHeight() / 1000f);
+            super.renderPage(page);
+        }
+
+
+        private List getInvalidPageNumbers() {
+
+            List list = new java.util.ArrayList();
+            int max = getPageCount();
+            boolean isValid;
+            for (int i = 0; i < max; i++) {
+                isValid = true;
+                if (i < startNumber || i > endNumber) {
+                    isValid = false;
+                } else if (mode != EVEN_AND_ALL) {
+                    if (mode == EVEN && ((i + 1) % 2 != 0)) {
+                        isValid = false;
+                    } else if (mode == ODD && ((i + 1) % 2 != 1)) {
+                        isValid = false;
+                    }
+                }
+
+                if (!isValid) {
+                    list.add(Integer.toString(i));
+                }
+            }
+
+            return list;
+        }
+    } // class PrintRenderer
+
+}
+

src/org/apache/fop/servlet/FopServlet.java

@@ -0,0 +1,212 @@
+/*
+ * $Id$
+ * Copyright (C) 2001-2003 The Apache Software Foundation. All rights reserved.
+ * For details on use and redistribution please refer to the
+ * LICENSE file included with these sources.
+ */
+
+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;
+
+// Avalon
+import org.apache.avalon.framework.logger.ConsoleLogger;
+import org.apache.avalon.framework.logger.Logger;
+
+//FOP
+import org.apache.fop.apps.Driver;
+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 $Id$
+ * @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 Logger 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 ConsoleLogger(ConsoleLogger.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
+        Driver driver = new Driver();
+        driver.enableLogging(this.log);
+        driver.setRenderer(Driver.RENDER_PDF);
+        driver.initialize();
+
+        //Setup output
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        driver.setOutputStream(out);
+        
+        //Make sure the XSL transformation's result is piped through to FOP
+        Result res = new SAXResult(driver.getContentHandler());
+        
+        //Start the transformation and rendering process
+        transformer.transform(src, res);
+
+        //Return the result
+        return out.toByteArray();
+    }
+
+}

src/org/apache/fop/servlet/package.html

@@ -0,0 +1,6 @@
+<HTML>
+  <TITLE>org.apache.fop.servlet Package</TITLE>
+  <BODY>
+    <P>This package contains two sample FOP servlets.</P>
+  </BODY>
+</HTML>