TransformServlet.java Source code

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Here is the source code for TransformServlet.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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: TransformServlet.java 470245 2006-11-02 06:34:33Z minchau $
 */

import java.io.IOException;
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.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerException;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

import org.xml.sax.SAXException;

/**
 * This servlet demonstrates how XSL transformations can be made available as
 * a web service. See the CompileServlet for an example on how stylesheets
 * can be pre-compiled before this servlet is invoked.
 *
 * Note that the XSLTC transformation engine is invoked through the JAXP
 * interface, using the XSLTC "use-classpath" attribute.  The
 * "use-classpath" attribute specifies to the XSLTC TransformerFactory
 * that a precompiled version of the stylesheet (translet) may be available,
 * and that that should be used in preference to recompiling the stylesheet.
 * @author Morten Jorgensen
 * @author Jacek Ambroziak
 */
public final class TransformServlet extends HttpServlet {

    /**
     * Main servlet entry point
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {

        // Initialise the output writer
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        // Get the two paramters "class" and "source".
        String transletName = request.getParameter("class");
        String documentURI = request.getParameter("source");

        try {
            if ((transletName == null) || (documentURI == null)) {
                out.println("<h1>XSL transformation error</h1>");
                out.println(
                        "The parameters <b><tt>class</tt></b> and " + "<b><tt>source</tt></b> must be specified");
            } else {
                TransformerFactory tf = TransformerFactory.newInstance();
                try {
                    tf.setAttribute("use-classpath", Boolean.TRUE);
                } catch (IllegalArgumentException iae) {
                    System.err.println("Could not set XSLTC-specific TransformerFactory "
                            + "attributes.  Transformation failed.");
                }
                Transformer t = tf.newTransformer(new StreamSource(transletName));

                // Start the transformation
                final long start = System.currentTimeMillis();
                t.transform(new StreamSource(documentURI), new StreamResult(out));
                final long done = System.currentTimeMillis() - start;
                out.println("<!-- transformed by XSLTC in " + done + "msecs -->");
            }
        } catch (Exception e) {
            out.println("<h1>Error</h1>");
            out.println(e.toString());
        }
    }
}