| /* |
| * 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. |
| */ |
| /* |
| * $Id$ |
| */ |
| |
| import java.io.IOException; |
| import java.io.PrintWriter; |
| import java.io.StringWriter; |
| |
| import java.util.StringTokenizer; |
| |
| import javax.xml.transform.Transformer; |
| import javax.xml.transform.TransformerFactory; |
| import javax.xml.transform.TransformerException; |
| import javax.xml.transform.ErrorListener; |
| import javax.xml.transform.stream.StreamResult; |
| import javax.xml.transform.stream.StreamSource; |
| |
| import sunlabs.brazil.server.Handler; |
| import sunlabs.brazil.server.Request; |
| import sunlabs.brazil.server.Server; |
| |
| /** |
| * This Brazil handler demonstrates how XSL transformations can be made |
| * available as a web service without using a full web server. This class |
| * implements the Handler interface from the Brazil project, see: |
| * http://www.sun.com/research/brazil/ |
| * |
| * Note that the XSLTC transformation engine is invoked through the JAXP |
| * interface, using the XSLTC "use-classpath" attribute. The |
| * "use-from-classpath" attribute specifies to the XSLTC TransformerFactory |
| * that a precompiled version of the stylesheet (translet) may be available, |
| * and that should be used in preference to recompiling the stylesheet. |
| * @author Morten Jorgensen |
| */ |
| public class TransformHandler implements Handler { |
| |
| private TransformerFactory m_tf = null; |
| |
| // These two are used while parsing the parameters in the URL |
| private final String PARAM_TRANSLET = "translet="; |
| private final String PARAM_DOCUMENT = "document="; |
| private final String PARAM_STATS = "stats="; |
| |
| // All output goes here: |
| private PrintWriter m_out = null; |
| |
| /** |
| * Dump an error message to output |
| */ |
| public void errorMessage(String message, Exception e) { |
| if (m_out == null) { |
| return; |
| } |
| m_out.println("<h1>XSL transformation error</h1>"+message); |
| m_out.println("<br>Exception:</br>"+e.toString()); |
| } |
| |
| public void errorMessage(String message) { |
| if (m_out == null) return; |
| m_out.println("<h1>XSL transformation error</h1>"+message); |
| } |
| |
| /** |
| * This method is run when the Brazil proxy is loaded |
| */ |
| public boolean init(Server server, String prefix) { |
| return true; |
| } |
| |
| /** |
| * This method is run for every HTTP request sent to the proxy |
| */ |
| public boolean respond(Request request) throws IOException { |
| |
| // Initialise the output buffer |
| final StringWriter sout = new StringWriter(); |
| m_out = new PrintWriter(sout); |
| |
| // These two hold the parameters from the URL 'translet' and 'document' |
| String transletName = null; |
| String document = null; |
| String stats = null; |
| |
| // Get the parameters from the URL |
| final StringTokenizer params = new StringTokenizer(request.query,"&"); |
| while (params.hasMoreElements()) { |
| final String param = params.nextToken(); |
| if (param.startsWith(PARAM_TRANSLET)) { |
| transletName = param.substring(PARAM_TRANSLET.length()); |
| } |
| else if (param.startsWith(PARAM_DOCUMENT)) { |
| document = param.substring(PARAM_DOCUMENT.length()); |
| } |
| else if (param.startsWith(PARAM_STATS)) { |
| stats = param.substring(PARAM_STATS.length()); |
| } |
| } |
| |
| try { |
| // Make sure that both parameters were specified |
| if ((transletName == null) || (document == null)) { |
| errorMessage("Parameters <b><tt>translet</tt></b> and/or "+ |
| "<b><tt>document</tt></b> not specified."); |
| } |
| else { |
| if (m_tf == null) { |
| m_tf = TransformerFactory.newInstance(); |
| try { |
| m_tf.setAttribute("use-classpath", Boolean.TRUE); |
| } catch (IllegalArgumentException iae) { |
| System.err.println( |
| "Could not set XSLTC-specific TransformerFactory " |
| + "attributes. Transformation failed."); |
| } |
| } |
| Transformer t = |
| m_tf.newTransformer(new StreamSource(transletName)); |
| |
| // Do the actual transformation |
| final long start = System.currentTimeMillis(); |
| t.transform(new StreamSource(document), |
| new StreamResult(m_out)); |
| final long done = System.currentTimeMillis() - start; |
| m_out.println("<!-- transformed by XSLTC in "+done+"ms -->"); |
| } |
| } |
| catch (Exception e) { |
| errorMessage("Internal error.",e); |
| } |
| |
| // Pass the transformation output as the HTTP response |
| request.sendResponse(sout.toString()); |
| return true; |
| } |
| |
| |
| } |