com.caricah.iotracah.bootstrap.system.handler.impl.DefaultConfigHandler.java Source code

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Here is the source code for com.caricah.iotracah.bootstrap.system.handler.impl.DefaultConfigHandler.java

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/*
 *
 * Copyright (c) 2015 Caricah <info@caricah.com>.
 *
 * Caricah licenses this file to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy
 *  of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software distributed under
 *  the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
 *  OF ANY  KIND, either express or implied.  See the License for the specific language
 *  governing permissions and limitations under the License.
 *
 *
 *
 *
 */

package com.caricah.iotracah.bootstrap.system.handler.impl;

import com.caricah.iotracah.bootstrap.system.handler.ConfigHandler;
import com.caricah.iotracah.bootstrap.exceptions.UnRetriableException;
import com.caricah.iotracah.bootstrap.system.ResourceFileUtil;
import org.apache.commons.configuration.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.nio.file.*;

/**
 *
 * The default system implementation for the configuration handler.
 *
 * @author <a href="mailto:bwire@caricah.com"> Peter Bwire </a>
 * @version 1.0 8/8/15
 */
public class DefaultConfigHandler implements ConfigHandler {

    private static final Logger log = LoggerFactory.getLogger(DefaultConfigHandler.class);

    private final String configurationDirectory;
    private final String configurationFileName;

    public DefaultConfigHandler() {

        //Try to use the system set property.
        this(System.getProperty("iotracah.default.path.conf", DEFAULT_CONFIG_DIRECTORY));

    }

    public DefaultConfigHandler(String configurationDirectory) {
        this(configurationDirectory, SYSTEM_CONFIG_CONFIGURATION_FILE_NAME_DEFAULT_VALUE);
    }

    public DefaultConfigHandler(String configurationDirectory, String configurationFileName) {

        if (null == configurationDirectory) {
            configurationDirectory = "";
        }
        this.configurationDirectory = configurationDirectory;
        this.configurationFileName = configurationFileName;
    }

    public String getConfigurationDirectory() {
        return configurationDirectory;
    }

    public String getConfigurationFileName() {
        return configurationFileName;
    }

    private Path getConfigurationFileInDirectory(String directory) throws IOException {

        String configFileName = getConfigurationFileName();

        File configFile = new File(directory + File.separator + configFileName);
        if (configFile.exists()) {

            log.debug(" getConfigurationFileInDirectory : matched file {} in config directory {}.", configFileName,
                    directory);
            return configFile.toPath();

        }
        return null;
    }

    /**
     * All system configurations providers are loaded via spi
     * and are given the configurations the system already has.
     * They are further expected to provide their configurations in
     * and additive way. Since the order of loading the configs is not
     * guranteed all the setting keys should be uniquely identified
     * and that task is left to the implementations to enforce.
     *
     * @param configuration
     * @return
     * @throws UnRetriableException
     */
    @Override
    public Configuration populateConfiguration(Configuration configuration) throws UnRetriableException {

        try {
            String configDirectory = getConfigurationDirectory();

            log.debug(" populateConfiguration : obtained config directory - {}", configDirectory);

            Path configurationFile = getConfigurationFileInDirectory(configDirectory);

            if (null == configurationFile) {

                configurationFile = ResourceFileUtil.getFileFromResource(getClass(), getConfigurationFileName())
                        .toPath();

            }

            if (configuration instanceof CompositeConfiguration) {
                ((CompositeConfiguration) configuration)
                        .addConfiguration(new PropertiesConfiguration(configurationFile.toFile()));
                return configuration;
            } else {
                CompositeConfiguration compositeConfiguration = new CompositeConfiguration();

                if (null != configuration) {
                    compositeConfiguration.addConfiguration(configuration);
                }

                compositeConfiguration.addConfiguration(new PropertiesConfiguration(configurationFile.toFile()));
                return compositeConfiguration;
            }

        } catch (IOException | ConfigurationException e) {
            log.error(" getConfiguration : ", e);
            throw new UnRetriableException(e);
        }

    }

}