001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software GmbH & Co. KG, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.main;
029
030import org.opencms.configuration.CmsParameterConfiguration;
031
032import java.io.IOException;
033
034import javax.servlet.ServletException;
035import javax.servlet.http.HttpServletRequest;
036import javax.servlet.http.HttpServletResponse;
037
038/**
039 * Describes an OpenCms request handler.<p>
040 *
041 * Request handlers are used for special requests to OpenCms
042 * that should NOT be mapped to a VFS resource.
043 * A request handler URI always start with <code>/handle</code> and then
044 * one or more possible handler names as defined with the {@link #getHandlerNames()}
045 * method.<p>
046 *
047 * For example, if a registerd request handler has the name <code>"MyName"</code>,
048 * any request (in a simple setup) to <code>/opencms/opencms/handlerMyName...</code> will directly be transfered
049 * to the {@link #handle(HttpServletRequest, HttpServletResponse, String)} method of this
050 * handler.<p>
051 *
052 * In essence, the request handlers are like simplified mini-servlets that run inside OpenCms.
053 * Of course they are not intended as replacements for real servlets.
054 * In case you require sophisticated lifecycle support use a genuine servlet instead.<p>
055 *
056 * @since 6.0.0
057 */
058public interface I_CmsRequestHandler {
059
060    /**
061     * Gets the configuration.
062     *
063     * @return the configuration
064     */
065    default CmsParameterConfiguration getConfiguration() {
066
067        return new CmsParameterConfiguration();
068    }
069
070    /**
071     * Returns the handler name.<p>
072     *
073     * @return the handler name
074     */
075    String[] getHandlerNames();
076
077    /**
078     * Handles an OpenCms request.<p>
079     *
080     * @param req the current request
081     * @param res the current response
082     * @param name the handler name to invoke
083     * @throws ServletException in case an error occurs
084     * @throws IOException in case an error occurs
085     */
086    void handle(HttpServletRequest req, HttpServletResponse res, String name) throws IOException, ServletException;
087
088    /**
089     * Initializes parameters.
090     *
091     * @param params the map of parameters
092     */
093    default void initParameters(CmsParameterConfiguration params) {
094
095        // do nothing
096    }
097}