de.ingrid.mdek.servlets.HelpServlet.java Source code

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Here is the source code for de.ingrid.mdek.servlets.HelpServlet.java

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/*
 * **************************************************-
 * Ingrid Portal MDEK Application
 * ==================================================
 * Copyright (C) 2014 - 2015 wemove digital solutions GmbH
 * ==================================================
 * Licensed under the EUPL, Version 1.1 or  as soon they will be
 * approved by the European Commission - subsequent versions of the
 * EUPL (the "Licence");
 * 
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * 
 * http://ec.europa.eu/idabc/eupl5
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 * **************************************************#
 */
package de.ingrid.mdek.servlets;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.ResourceBundle;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamSource;

import org.apache.log4j.Logger;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.io.DocumentResult;
import org.dom4j.io.DocumentSource;
import org.dom4j.io.SAXReader;
import org.dom4j.tree.DefaultElement;

public class HelpServlet extends HttpServlet {

    private final static Logger log = Logger.getLogger(HelpServlet.class);

    // base filename for the xml helpfile. Additional chars are added depending on the request locale before '.xml'
    // e.g. if the base filename is 'mdek-application-help.xml' and the locale is 'en', the resulting String will be:
    // mdek-application-help_en.xml
    private String baseHelpFileName = null;
    private String xslFileName = null;

    public void init() throws ServletException {
        ResourceBundle resourceBundle = ResourceBundle.getBundle("help");
        baseHelpFileName = "/WEB-INF/classes/" + resourceBundle.getString("help.baseFileName");
        xslFileName = "/WEB-INF/classes/" + resourceBundle.getString("help.xslFileName");
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException {
        HttpSession session = request.getSession();
        Enumeration<String> enumeration = request.getParameterNames();

        while (enumeration.hasMoreElements()) {
            String parameterName = enumeration.nextElement();
            String parameter = (String) request.getParameter(parameterName);
            log.debug("parameter name: " + parameterName);
            log.debug("parameter value: " + parameter);
        }

        String fileName = baseHelpFileName.substring(0, baseHelpFileName.lastIndexOf(".xml")) + "_"
                + request.getSession().getAttribute("currLang") + ".xml";

        response.setContentType("text/html");
        response.setCharacterEncoding("UTF8");

        PrintWriter out = null;
        try {
            out = response.getWriter();

        } catch (IOException e) {
            log.error("Could not open PrintWriter.", e);
            throw new ServletException(e);
        }

        // read help resource
        SAXReader xmlReader = new SAXReader();
        Document doc = null;
        try {
            doc = xmlReader.read(getServletContext().getResourceAsStream(fileName));

        } catch (Exception e) {
            //            log.error("Error reading help source file!", e);
        }

        // If the doc could not be found, use the base help filename
        if (doc == null) {
            try {
                doc = xmlReader.read(getServletContext().getResourceAsStream(baseHelpFileName));

            } catch (Exception e) {
                log.error("Error reading help source file!", e);
                throw new ServletException(e);
            }
        }

        // get the help chapter
        String helpKey = request.getParameter("hkey");
        if (helpKey == null) {
            helpKey = "index";
        }
        Object chapterObj = doc.selectSingleNode("//section[@help-key='" + helpKey + "']/ancestor::chapter");

        // transform the xml content to valid html using xslt
        if (chapterObj == null) {
            //           context.put("help_content", "<p>help key (" + helpKey + ") not found!</p>");
            out.print("<p>help key (" + helpKey + ") not found!</p>");

        } else {
            TransformerFactory factory;
            try {
                factory = TransformerFactory.newInstance();
            } catch (Throwable t) {
                System.setProperty("javax.xml.transform.TransformerFactory",
                        "com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl");
                factory = TransformerFactory.newInstance();
            }

            try {
                StreamSource stylesheet = new StreamSource(getServletContext().getResourceAsStream(xslFileName));
                Transformer transformer = factory.newTransformer(stylesheet);
                DocumentResult result = new DocumentResult();
                String subtree = ((DefaultElement) chapterObj).asXML();
                DocumentSource source = new DocumentSource(DocumentHelper.parseText(subtree));

                transformer.transform(source, result);
                String helpContent = result.getDocument().asXML();
                //                context.put("help_content", helpContent);
                out.print(helpContent);

            } catch (Exception e) {
                log.error("Error processing help entry!", e);
            }
        }
    }
}