edu.mayo.cts2.framework.plugin.web.editor.StaticHttpService.java Source code

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Here is the source code for edu.mayo.cts2.framework.plugin.web.editor.StaticHttpService.java

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/*
 * Copyright: (c) 2004-2011 Mayo Foundation for Medical Education and 
 * Research (MFMER). All rights reserved. MAYO, MAYO CLINIC, and the
 * triple-shield Mayo logo are trademarks and service marks of MFMER.
 *
 * Except as contained in the copyright notice above, or as used to identify 
 * MFMER as the author of this software, the trade names, trademarks, service
 * marks, or product names of the copyright holder shall not be used in
 * advertising, promotion or otherwise in connection with this software without
 * prior written authorization of the copyright holder.
 *
 * Licensed 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.
 */
package edu.mayo.cts2.framework.plugin.web.editor;

import java.io.IOException;
import java.io.InputStream;

import javax.servlet.GenericServlet;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.service.http.HttpService;
import org.osgi.util.tracker.ServiceTracker;
import org.osgi.util.tracker.ServiceTrackerCustomizer;

/**
 * A simple Servlet for serving up static content.
 *
 * @author <a href="mailto:kevin.peterson@mayo.edu">Kevin Peterson</a>
 */
public class StaticHttpService extends GenericServlet implements BundleActivator {

    private static final long serialVersionUID = -420835724412643550L;
    private ServiceTracker httpTracker;

    /* (non-Javadoc)
     * @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext)
     */
    public void start(final BundleContext context) throws Exception {
        this.httpTracker = new ServiceTracker(context, HttpService.class.getName(), new ServiceTrackerCustomizer() {

            public Object addingService(ServiceReference reference) {
                HttpService httpService = (HttpService) context.getService(reference);

                try {
                    httpService.registerServlet("/editor", StaticHttpService.this, null, null);

                    httpService.registerResources("/editor/resources", "/resources", null);
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }

                return context.getService(reference);
            }

            public void modifiedService(ServiceReference reference, Object service) {
                //
            }

            public void removedService(ServiceReference reference, Object service) {
                //
            }

        });
        this.httpTracker.open();
    }

    /* (non-Javadoc)
     * @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext)
     */
    public void stop(BundleContext context) throws Exception {
        this.httpTracker.close();
    }

    /* (non-Javadoc)
     * @see javax.servlet.GenericServlet#service(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
     */
    public void service(final ServletRequest req, final ServletResponse res) throws ServletException, IOException {
        // don't really expect to be called within a non-HTTP environment
        service((HttpServletRequest) req, (HttpServletResponse) res);

        // ensure response has been sent back and response is committed
        // (we are authorative for our URL space and no other servlet should
        // interfere)
        res.flushBuffer();
    }

    /**
     * Service the request. The only path recognized by this servlet is
     * \/editor/console - all others will be delegated to OSGi resource handling.
     *
     * @param request the request
     * @param response the response
     * @throws ServletException the servlet exception
     * @throws IOException Signals that an I/O exception has occurred.
     */
    private void service(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // check whether we are not at .../{webManagerRoot}
        final String pathInfo = request.getPathInfo();

        if (pathInfo.equals("/console")) {
            InputStream in = this.getClass().getResourceAsStream("/index.html");

            response.setContentType("text/html");

            IOUtils.copy(in, response.getWriter());
        }
    }
}