PresenterBrowserServlet.java

/*
 *  This file is part of Daxplore Presenter.
 *
 *  Daxplore Presenter is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 2.1 of the License, or
 *  (at your option) any later version.
 *
 *  Daxplore Presenter is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Daxplore Presenter.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.daxplore.presenter.server.servlets;

import java.io.IOException;
import java.io.Writer;
import java.text.MessageFormat;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;
import org.daxplore.presenter.server.throwable.InternalServerException;

@SuppressWarnings("serial")
public class PresenterBrowserServlet extends HttpServlet {
	private static Logger logger = Logger.getLogger(PresenterBrowserServlet.class.getName());
	private static String welcomeTemplate = null;
	
	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response) {
		try {
			if (welcomeTemplate == null) {
				try {
					welcomeTemplate = IOUtils.toString(getServletContext().getResourceAsStream("/templates/welcome.html"));
				} catch (IOException e) {
					throw new InternalServerException("Failed to load the welcome template", e);
				}
			}
			
			String baseurl = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort();
			
			String[] arguments = {
					baseurl
				};
			
			String responseHTML = MessageFormat.format(welcomeTemplate, (Object[])arguments);
			
			response.setContentType("text/html; charset=UTF-8");
			try (Writer writer = response.getWriter()) {
				writer.write(responseHTML);
			} catch (IOException e) {
				throw new InternalServerException("Failed to display presenter servlet", e);
			}
		} catch (InternalServerException e) {
			logger.log(Level.SEVERE, e.getMessage(), e);
			response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
		} catch (Exception e) {
			logger.log(Level.SEVERE, "Unexpected exception: " + e.getMessage(), e);
			response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
		}
	}
}