org.veronicadb.core.configuration.ConfigurationManager.java Source code

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Here is the source code for org.veronicadb.core.configuration.ConfigurationManager.java

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/*
 * 
 * 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 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.  If not, see <http://www.gnu.org/licenses/>.2
 */
package org.veronicadb.core.configuration;

import java.net.URISyntaxException;
import java.util.Arrays;

import org.apache.commons.configuration.CompositeConfiguration;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.commons.configuration.XMLConfiguration;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

/**
 * Configuration Manager singleton.
 * 
 * @author ambudsharma
 */
public class ConfigurationManager {

    private static final Logger logger = LogManager.getLogger(ConfigurationManager.class);
    public static final String ENV_VERONICA_CONFIG = "VERONICA_CONFIG";
    private static final String CONFIG_BASE_PREFIX = "org.veronica.";
    private static final String CONFIG_SECURITY_PREFIX = CONFIG_BASE_PREFIX + "security.";
    private static final String CONFIG_STORAGE_PREFIX = CONFIG_BASE_PREFIX + "storage.";
    public static final String VERONICA_VERSION = CONFIG_BASE_PREFIX + "version";

    public static enum ConfigType {
        XML, PROP
    };

    private final Configuration config;
    private static ConfigurationManager self;

    private ConfigurationManager() throws ConfigurationException, URISyntaxException {
        Configuration configuration = loadDefaultConfiguration();
        String configPath = System.getenv(ENV_VERONICA_CONFIG);
        logger.info("Checking custom configuration in environment variable");
        if (configPath == null) {
            logger.info("Environment variable not found, trying system property");
            configPath = System.getProperty(ENV_VERONICA_CONFIG);
        }
        if (configPath != null) {
            logger.info("Loading custom configuration");
            Configuration overrideConfig = loadConfiguration(ConfigType.PROP, configPath);
            config = new CompositeConfiguration(Arrays.asList(configuration, overrideConfig));
        } else {
            config = configuration;
        }
    }

    private Configuration loadDefaultConfiguration() throws ConfigurationException, URISyntaxException {
        return loadConfiguration(ConfigType.PROP,
                ConfigurationManager.class.getResource("/config/veronica.properties").toURI().toASCIIString());
    }

    protected Configuration loadConfiguration(ConfigType type, String configPath) throws ConfigurationException {
        Configuration configuration = null;
        switch (type) {
        case PROP:
            configuration = new PropertiesConfiguration(configPath);
            break;
        case XML:
            configuration = new XMLConfiguration(configPath);
            break;
        default:
            throw new ConfigurationException("Invalid configuration type");
        }
        return configuration;
    }

    public static ConfigurationManager getInstance() throws ConfigurationException, URISyntaxException {
        if (self == null) {
            self = new ConfigurationManager();
        }
        return self;
    }

    public Configuration getSecurityConfiguration() {
        return config.subset(CONFIG_SECURITY_PREFIX);
    }

    public Configuration getStorageConfiguration() {
        return config.subset(CONFIG_STORAGE_PREFIX);
    }

    /**
     * Get All configuration in the raw format
     * @return global veronica configuration
     */
    public Configuration getRawConfig() {
        return config;
    }

    /**
     * Get All configuration without the base prefix
     * @return global veronica configuration
     */
    public Configuration getConfig() {
        return config.subset(CONFIG_BASE_PREFIX);
    }

}