ddf.security.common.util.PropertiesLoader.java Source code

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Here is the source code for ddf.security.common.util.PropertiesLoader.java

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/**
 * Copyright (c) Codice Foundation
 * 
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or 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
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 * 
 **/
package ddf.security.common.util;

import org.slf4j.LoggerFactory;
import org.slf4j.ext.XLogger;
import org.springframework.core.io.support.PropertiesLoaderUtils;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

/**
 * Utility class that attempts several different methods for loading in properties files from the
 * classpath or file system.
 * 
 * @author tustisos
 * 
 */
public final class PropertiesLoader {
    private static XLogger logger = new XLogger(LoggerFactory.getLogger(PropertiesLoader.class));

    private PropertiesLoader() {
        // static only!
    }

    @SuppressWarnings("unchecked")
    public static <K, V> Map<K, V> toMap(Properties properties) {
        if (properties != null) {
            Set<K> keySet = (Set<K>) properties.keySet();
            Map<K, V> map = new HashMap<K, V>(keySet.size() * 2);
            for (K obj : keySet) {
                map.put(obj, (V) properties.get(obj));
            }
            return map;
        }
        return new HashMap<K, V>();
    }

    /**
     * Load properties from a file with no classloader specified.
     * 
     * @param propertiesFile
     * @return Properties
     */
    public static Properties loadProperties(String propertiesFile) {
        return loadProperties(propertiesFile, null);
    }

    /**
     * Will attempt to load properties from a file using the given classloader. If that fails,
     * several other methods will be tried until the properties file is located.
     * 
     * @param propertiesFile
     * @param classLoader
     * @return Properties
     */
    public static Properties loadProperties(String propertiesFile, ClassLoader classLoader) {
        boolean error = false;
        Properties properties = new Properties();
        if (propertiesFile != null) {
            try {
                if (logger.isDebugEnabled()) {
                    logger.debug("Attempting to load properties from " + propertiesFile
                            + " with Spring PropertiesLoaderUtils.");
                }
                properties = PropertiesLoaderUtils.loadAllProperties(propertiesFile);
            } catch (IOException e) {
                error = true;
                logger.error("Unable to load properties using default Spring properties loader.", e);
            }
            if (error || properties.isEmpty()) {
                if (classLoader != null) {
                    try {
                        if (logger.isDebugEnabled()) {
                            logger.debug("Attempting to load properties from " + propertiesFile
                                    + " with Spring PropertiesLoaderUtils with class loader.");
                        }
                        properties = PropertiesLoaderUtils.loadAllProperties(propertiesFile, classLoader);
                        error = false;
                    } catch (IOException e) {
                        error = true;
                        logger.error("Unable to load properties using default Spring properties loader.", e);
                    }
                } else {
                    try {
                        if (logger.isDebugEnabled()) {
                            logger.debug("Attempting to load properties from " + propertiesFile
                                    + " with Spring PropertiesLoaderUtils with class loader.");
                        }
                        properties = PropertiesLoaderUtils.loadAllProperties(propertiesFile,
                                PropertiesLoader.class.getClassLoader());
                        error = false;
                    } catch (IOException e) {
                        error = true;
                        logger.error("Unable to load properties using default Spring properties loader.", e);
                    }
                }
            }

            if (error || properties.isEmpty()) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Attempting to load properties from file system: " + propertiesFile);
                }
                File propFile = null;
                if (propertiesFile.startsWith("/")) {
                    propFile = new File(propertiesFile);
                } else {
                    String karafHome = System.getProperty("karaf.home");
                    if (karafHome != null && !karafHome.isEmpty()) {
                        propFile = new File(karafHome, propertiesFile);
                    } else {
                        karafHome = System.getProperty("ddf.home");
                        if (karafHome != null && !karafHome.isEmpty()) {
                            propFile = new File(karafHome, propertiesFile);
                        } else {
                            propFile = new File(propertiesFile);
                        }
                    }
                }
                properties = new Properties();
                try {
                    properties.load(new FileReader(propFile));
                } catch (FileNotFoundException e) {
                    error = true;
                    logger.error("Could not find properties file: " + propFile.getAbsolutePath(), e);
                } catch (IOException e) {
                    error = true;
                    logger.error("Error reading properties file: " + propFile.getAbsolutePath(), e);
                }
            }
            if (error || properties.isEmpty()) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Attempting to load properties as a resource: " + propertiesFile);
                }
                InputStream ins = PropertiesLoader.class.getResourceAsStream(propertiesFile);
                if (ins != null) {
                    try {
                        properties.load(ins);
                        ins.close();
                    } catch (IOException e) {
                        logger.error("Unable to load properties: " + propertiesFile, e);
                    } finally {
                        try {
                            ins.close();
                        } catch (IOException ignore) {
                        }
                    }
                }
            }
        } else {
            if (logger.isDebugEnabled()) {
                logger.debug("Properties file must not be null.");
            }
        }

        return properties;
    }
}