esa.mo.mal.impl.util.StructureHelper Maven / Gradle / Ivy

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/* ----------------------------------------------------------------------------
 * Copyright (C) 2013      European Space Agency
 *                         European Space Operations Centre
 *                         Darmstadt
 *                         Germany
 * ----------------------------------------------------------------------------
 * System                : CCSDS MO MAL Java Implementation
 * ----------------------------------------------------------------------------
 * Licensed under the European Space Agency Public License, Version 2.0
 * You may not use this file except in compliance with the License.
 *
 * Except as expressly set forth in this License, the Software is provided to
 * You on an "as is" basis and without warranties of any kind, including without
 * limitation merchantability, fitness for a particular purpose, absence of
 * defects or errors, accuracy or non-infringement of intellectual property rights.
 * 
 * See the License for the specific language governing permissions and
 * limitations under the License. 
 * ----------------------------------------------------------------------------
 */
package esa.mo.mal.impl.util;

import java.util.Properties;
import java.util.Set;
import java.util.TreeSet;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.ccsds.moims.mo.mal.structures.Identifier;
import org.ccsds.moims.mo.mal.structures.IdentifierList;

/**
 * Helper class that contains useful utility functions. It also stores a list of
 * loaded property files so that the same property file is not loaded multiple
 * times.
 *
 */
public abstract class StructureHelper {

    private static final Set LOADED_PROPERTIES = new TreeSet();

    private StructureHelper() {
    }

    /**
     * Loads in a property file and optionally searches for a contained property
     * that contains the next file to load.
     *
     * @param configFile The name of the property file to load. May be null, in
     * which case nothing is loaded.
     * @param chainProperty The property name that contains the name of the next
     * file to load.
     * @return The loaded properties or an empty list if no file loaded.
     */
    public static Properties loadProperties(final String configFile, final String chainProperty) {
        Properties topProps = new Properties();

        if (null != configFile) {
            final java.net.URL url = ClassLoader.getSystemClassLoader().getResource(configFile);
            if ((null != url) && (!LOADED_PROPERTIES.contains(url.toString()))) {
                LOADED_PROPERTIES.add(url.toString());

                try {
                    final Properties myProps = new Properties();
                    myProps.load(url.openStream());

                    final Properties subProps = loadProperties(
                            myProps.getProperty(chainProperty), chainProperty);

                    Logger.getLogger("org.ccsds.moims.mo.mal.impl.util").log(
                            Level.INFO,
                            "Loading properties from {0}", url.toString());
                    topProps.putAll(subProps);
                    topProps.putAll(myProps);
                } catch (Exception ex) {
                    Logger.getLogger("org.ccsds.moims.mo.mal.impl.util").log(
                            Level.WARNING,
                            "Failed to load properties file {0} {1}",
                            new Object[]{url, ex});
                }
            }
        }

        return topProps;
    }

    /**
     * Converts a identifier list version of a domain name to a single, dot
     * delimited, String.
     *
     * @param domain The list of identifiers to concatenate.
     * @return The dot delimited version of the domain name.
     */
    public static String domainToString(final IdentifierList domain) {
        String retVal = null;

        if (null != domain) {
            final StringBuilder buf = new StringBuilder();
            int i = 0;
            final int e = domain.size();
            while (i < e) {
                if (0 < i) {
                    buf.append('.');
                }

                buf.append((Identifier) domain.get(i));

                ++i;
            }

            retVal = buf.toString();
        }

        return retVal;
    }

    /**
     * Determines if one domain is a sub-domain, or the same domain, of another.
     * For example, a.b.c is a sub-domain of a.b
     *
     * @param srcDomain The main domain.
     * @param testDomain The sub-domain.
     * @return True if tesDomain is a sub-domain of srcDomain, else false.
     */
    public static boolean isSubDomainOf(final IdentifierList srcDomain,
            final IdentifierList testDomain) {
        if ((null != srcDomain) && (null != testDomain)) {
            if (srcDomain.size() <= testDomain.size()) {
                int i = 0;
                final int e = srcDomain.size();
                while (i < e) {
                    final Identifier sId = srcDomain.get(i);
                    final Identifier tId = testDomain.get(i);

                    if (sId == null ? tId != null : !sId.equals(tId)) {
                        return false;
                    }

                    ++i;
                }

                return true;
            }
        } else {
            if ((null == srcDomain) && (null == testDomain)) {
                return true;
            }
        }

        return false;
    }
}