source: main/trunk/greenstone3/src/java/org/greenstone/util/GlobalProperties.java@ 24896

/*
 *    GlobalProperties.java
 *    Copyright (C) 2008 New Zealand Digital Library, http://www.nzdl.org
 *
 *    This program 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 program 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.greenstone.util;

import java.util.Properties;
import java.io.File;
import java.io.InputStream;

import org.apache.log4j.*;

/**
 * holds some global properties for the application. Read from a properties file
 */
public class GlobalProperties
{
    static Logger logger = Logger.getLogger(org.greenstone.util.GlobalProperties.class.getName());
    private static Properties properties = null;
    private static String properties_filename = "global.properties";
    private static String gsdl3_home = null;
    private static String gsdl3_web_address = null;

    // Note, that if the servlet is reloadable, then it is reloaded each time the file is changed.
    static
    {
        //load in the properties
        properties = new Properties();
        reload();
    }

    /** get the value of the property 'key'. returns null if not found */
    public static String getProperty(String key)
    {
        return properties.getProperty(key);
    }

    /**
     * get the value of the property 'key'. returns default_value if not found
     */
    public static String getProperty(String key, String default_value)
    {
        return properties.getProperty(key, default_value);
    }

    /** some special ones */
    public static String getGSDL3Home()
    {
        return gsdl3_home;
    }

    public static String getGSDL3WebAddress()
    {
        return gsdl3_web_address;
    }

    public static void reload()
    {
        try
        {

            InputStream in = Class.forName("org.greenstone.util.GlobalProperties").getClassLoader().getResourceAsStream(properties_filename);
            if (in != null)
            {
                logger.debug("loading global properties");
                properties.load(in);
                in.close();
            }
            else
            {
                logger.error("couldn't load global properties!");
            }
            gsdl3_home = properties.getProperty("gsdl3.home");
            // make sure the path separators are correct
            File gs3_file = new File(gsdl3_home);
            gsdl3_home = gs3_file.getPath();

            //build the gsdl3 web address, in a way resilient to errors and ommisions in global.properties, simplifying where possible
            //aiming for a string with no trailing slash, eg "http://localhost:8080/greenstone3" or "http://www.mygreenstonelibrary.com"
            String protocolSpecifier = null, hostSpecifier = null, portSpecifier = null, contextSpecifier = null;

            //protocol
            if (properties.getProperty("tomcat.protocol") == null || properties.getProperty("tomcat.protocol").equals(""))
            {
                protocolSpecifier = "http://";
            }
            else
            {
                if (properties.getProperty("tomcat.protocol").endsWith("://"))
                {
                    protocolSpecifier = properties.getProperty("tomcat.protocol");
                }
                else
                {
                    protocolSpecifier = properties.getProperty("tomcat.protocol") + "://";
                }
            }

            //hostname
            if (properties.getProperty("tomcat.server") == null)
            {
                hostSpecifier = "localhost";
            }
            else
            {
                hostSpecifier = properties.getProperty("tomcat.server");
                while (hostSpecifier.endsWith("/"))
                {
                    hostSpecifier = hostSpecifier.substring(0, hostSpecifier.length() - 1);
                }
            }

            //port
            if (properties.getProperty("tomcat.port") == null || properties.getProperty("tomcat.port").equals("") || (protocolSpecifier.equals("http://") && properties.getProperty("tomcat.port").equals("80")) || (protocolSpecifier.equals("https://") && properties.getProperty("tomcat.port").equals("443")))
            {
                portSpecifier = "";
            }
            else
            {
                portSpecifier = ":" + properties.getProperty("tomcat.port");
            }

            //context path
            if (properties.getProperty("tomcat.context") == null || properties.getProperty("tomcat.context").equals("") || properties.getProperty("tomcat.context").equals("/"))
            {
                contextSpecifier = "";
            }
            else
            {
                contextSpecifier = properties.getProperty("tomcat.context");
                if (!contextSpecifier.startsWith("/"))
                {
                    contextSpecifier = "/" + contextSpecifier;
                }
            }

            //string it all together
            gsdl3_web_address = protocolSpecifier + hostSpecifier + portSpecifier + contextSpecifier;

        }
        catch (Exception e)
        {
            logger.error("Exception trying to reload global.properties: " + e);
        }
    }
}