ibw.updater.common.config.ConfigurationLoader.java Source code

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Here is the source code for ibw.updater.common.config.ConfigurationLoader.java

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/*
 * This program is free software; you can use it, redistribute it
 * and / or modify it under the terms of the GNU General Public License
 * (GPL) as published by the Free Software Foundation; either version 3
 * 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, in a file called gpl.txt or license.txt.
 * If not, write to the Free Software Foundation Inc.,
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307 USA
 */
package ibw.updater.common.config;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Map;
import java.util.StringTokenizer;

import org.apache.commons.io.input.TeeInputStream;

/**
 * The Class ConfigurationLoader.
 *
 * @author Ren\u00E9 Adler (eagle)
 */
public class ConfigurationLoader {

    protected AppProperties properties;

    /**
     * Instantiates a new configuration loader.
     */
    public ConfigurationLoader() {
        this.properties = new AppProperties();
        try (InputStream in = getConfigInputStream()) {
            loadFromStream(in);
        } catch (IOException e) {
            throw new ConfigurationException("Could not load config properties.", e);
        }
    }

    private InputStream getConfigInputStream() throws IOException {
        ConfigurationInputStream configurationInputStream = ConfigurationInputStream.getConfigPropertiesInstance();
        File configFile = ConfigurationDir.getConfigFile("config.active.properties");
        if (configFile != null) {
            FileOutputStream fout = new FileOutputStream(configFile);
            TeeInputStream tin = new TeeInputStream(configurationInputStream, fout, true);
            return tin;
        }
        return configurationInputStream;
    }

    /**
     * Load.
     *
     * @return the map
     */
    public Map<String, String> load() {
        return properties.getAsMap();
    }

    /**
     * Loads configuration properties from a specified properties file and adds
     * them to the properties currently set. This method scans the <CODE>
     * CLASSPATH</CODE> for the properties file, it may be a plain file, but may
     * also be located in a zip or jar file. If the properties file contains a
     * property called <CODE>Configuration.Include</CODE>, the files specified
     * in that property will also be read. Multiple include files have to be
     * separated by spaces or colons.
     * 
     * @param filename
     *            the properties file to be loaded
     * @throws ConfigurationException
     *             if the file can not be loaded
     */
    private void loadFromFile(String filename) {
        File configProperties = new File(filename);
        InputStream input = null;
        try {
            if (configProperties.canRead()) {
                input = new FileInputStream(configProperties);
            } else {
                URL url = this.getClass().getResource("/" + filename);
                if (url == null) {
                    throw new ConfigurationException("Could not find file or resource:" + filename);
                }
                input = url.openStream();
            }
            loadFromStream(input);
        } catch (IOException e) {
            throw new ConfigurationException("Could not load configuration from: " + filename, e);
        }
    }

    private void loadFromStream(InputStream input) throws IOException {
        try (InputStream in = input) {
            properties.load(in);
        }
        String include = properties.getProperty("Configuration.Include", null);

        if (include != null) {
            StringTokenizer st = new StringTokenizer(include, ", ");
            properties.remove("Configuration.Include");
            while (st.hasMoreTokens()) {
                loadFromFile(st.nextToken());
            }
        }
    }
}