com.thruzero.common.core.config.JFigConfig.java Source code

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Here is the source code for com.thruzero.common.core.config.JFigConfig.java

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/*
 *   Copyright 2005-2011 George Norman
 *
 *   Licensed 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.thruzero.common.core.config;

import java.io.File;
import java.util.Collections;
import java.util.Map;
import java.util.Set;

import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;
import org.igfay.jfig.JFig;
import org.igfay.jfig.JFigConstants;
import org.igfay.jfig.JFigException;
import org.igfay.jfig.JFigIF;
import org.igfay.jfig.JFigLocator;

import com.thruzero.common.core.locator.InitializationException;
import com.thruzero.common.core.locator.InitializationStrategy;
import com.thruzero.common.core.locator.LocatorUtils;
import com.thruzero.common.core.map.StringMap;
import com.thruzero.common.core.utils.ExceptionUtilsExt;

/**
 * A {@code Config} implementation based on <a href="http://jfig.sourceforge.net/">JFig</a>.
 *
 * @author George Norman
 * @see {@link com.thruzero.common.core.locator.ConfigLocator ConfigLocator}
 */
public final class JFigConfig extends AbstractConfig {
    private static final Logger logger = Logger.getLogger(AbstractConfig.class);

    private JFigIF jFig;

    /**
     * The SecurityManager does not allow construction with a non-default constructor (if the constructor is private), so
     * the init(StringMap) method is used instead of a constructor that takes params.
     * <p>
     * Use {@link com.thruzero.common.core.locator.ConfigLocator#locate()} to get an instance of the registered Config.
     */
    private JFigConfig() {
    }

    /**
     * Initializes the JFig instance, on first call; all subsequent calls will be ignored.
     *
     * @throws InitializationException if a problem is encountered with the given initParams.
     */
    @Override
    public void init(final InitializationStrategy initStrategy) {
        if (jFig == null) {
            // Note: The ConfigLocatorStrategy creates a MapInitializationStrategy containing the config file name (and path).
            // These params are typically read from the web.xml file when used in a web server environment.
            StringMap initParams = LocatorUtils.getInheritedParameters(initStrategy, this.getClass(), Config.class);

            // get the config file and directory
            String filePath = LocatorUtils.getRequiredParam(initParams, this.getClass().getName(),
                    ConfigInitParamKeys.CONFIG_FILE_PATH_PARAM, initStrategy);
            File configFile = new File(filePath);
            String configDirectory = getConfigDirectory(configFile);

            // init JFig via, first using file path and falling back on classpath if that fails.
            JFigLocator jfigLocator = new JFigLocator(configFile.getName());

            try {
                jfigLocator.setConfigDirectory(configDirectory);
                jfigLocator.setConfigLocation(JFigConstants.FILE);
                JFig.initialize(jfigLocator);
                logger.debug("# JFig initialized from: " + configFile.getAbsolutePath());
            } catch (JFigException jfe) {
                try {
                    // try again, this time using classpath
                    jfigLocator.setConfigLocation(JFigConstants.CLASSPATH);
                    JFig.initialize(jfigLocator);
                } catch (JFigException e) {
                    logger.error("**************************");
                    logger.error("ERROR: JFig failed initialization: " + e.getMessage());
                    logger.error("**************************");
                    throw new InitializationException("JFig failed initialization: ", e, initStrategy);
                }
            }

            jFig = JFig.getInstance();
        }
    }

    @Override
    public void reset() {

    }

    @Override
    public Map<String, String> getSection(final String sectionName) {
        Map<String, String> result = null;
        @SuppressWarnings("unchecked")
        Map<String, String> section = jFig.getSection(sectionName);

        if (StringUtils.isEmpty(sectionName)) {
            throw new RuntimeException(ExceptionUtilsExt.decorateMessageLevel1(
                    "The requested Config Section name is empty. Section name is: " + sectionName));
        }

        if (section != null) {
            result = Collections.unmodifiableMap(section);
        }

        return result;
    }

    @Override
    public Set<String> getSectionNames() {
        @SuppressWarnings("unchecked")
        Set<String> result = Collections
                .unmodifiableSet(jFig.getConfigDictionary().getDictionaryOfSectionDictionaries().keySet());

        return result;
    }

}