Application.java

/*
 * Application.java
 *
 * This work 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 of the License,
 * or (at your option) any later version.
 *
 * This work 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 * Copyright (c) 2004 Per Cederberg. All rights reserved.
 */

package org.liquidsite.app.servlet;

import java.io.File;

import javax.servlet.ServletContext;

import org.liquidsite.core.content.ContentManager;
import org.liquidsite.util.db.DatabaseConnector;

/**
 * The application context. This interface provides the basic
 * infrastructure for inter-application communication and for sharing
 * global datastructures.
 *
 * @author   Per Cederberg, <per at percederberg dot net>
 * @version  1.0
 */
public interface Application {

    /**
     * Checks if the application is running correctly. This method
     * will return true if no major errors have been encountered,
     * such as database connections are not working or similar. Note
     * that this method may return true even if the application is
     * not installed, assuming that the installed has been properly
     * launched.
     *
     * @return true if the application is online and working, or
     *         false otherwise
     */
    boolean isOnline();

    /**
     * Restarts the application. This will perform a partial shutdown
     * followed by a startup, flushing and rereading all
     * datastructures, such as configuration, database connections,
     * and similar.
     */
    void restart();

    /**
     * Returns the application build version number.
     *
     * @return the application build version number
     */
    String getBuildVersion();

    /**
     * Returns the application build date.
     *
     * @return the application build date
     */
    String getBuildDate();

    /**
     * Returns the base application directory. This is the directory
     * containing all the application files (i.e. the corresponding
     * webapps directory).
     *
     * @return the base application directory
     */
    File getBaseDir();

    /**
     * Returns the application configuration. The object returned by
     * this method will not change, unless a reset is made, but the
     * parameter values in the configuration may be modified.
     *
     * @return the application configuration
     */
    Configuration getConfig();

    /**
     * Returns the application database connector. The object
     * returned by this method will not change, unless a reset is
     * made.
     *
     * @return the application database connector
     */
    DatabaseConnector getDatabase();

    /**
     * Returns the application content manager. The object returned
     * by this method will not change, unless a reset is made.
     *
     * @return the application content manager
     */
    ContentManager getContentManager();

    /**
     * Returns the application servlet context.
     *
     * @return the application servlet context
     */
    ServletContext getServletContext();
}