source: greenstone3/trunk/src/java/org/greenstone/gsdl3/util/GlobalProperties.java@ 19642

/*
 *    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.gsdl3.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.gsdl3.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.gsdl3.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 );
        }
    }
}