Utils.java

/**
 * This program 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
 * (at your option) any later version.
 * <p/>
 * 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.
 * <p/>
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @author Nuno Oliveira, GeoSolutions S.A.S., Copyright 2016
 */
package org.geowebcache.sqlite;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.geowebcache.io.ByteArrayResource;
import org.geowebcache.io.Resource;

import java.io.File;
import java.nio.file.Files;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.UUID;

/**
 * Some utilities objects and functions used internally.
 */
final class Utils {

    private static Log LOGGER = LogFactory.getLog(Utils.class);

    // if we get the windows path separator we need to escape it for regex use
    static final String REGEX_FILE_SEPARATOR = File.separator.equals("\\") ? "\\\\" : File.separator;

    private Utils() {
    }

    static final class Tuple<T, U> {

        final T first;
        final U second;

        private Tuple(T first, U second) {
            this.first = first;
            this.second = second;
        }

        static <R, S> Tuple<R, S> tuple(R first, S second) {
            return new Tuple<>(first, second);
        }

        @Override
        public boolean equals(Object object) {
            if (this == object) return true;
            if (object == null || getClass() != object.getClass()) return false;
            Tuple<?, ?> tuple = (Tuple<?, ?>) object;
            return Objects.equals(first, tuple.first) &&
                    Objects.equals(second, tuple.second);
        }

        @Override
        public int hashCode() {
            return Objects.hash(first, second);
        }
    }

    @SafeVarargs
    static <K, V> Map<K, V> tuplesToMap(Tuple<K, V>... tuples) {
        Map<K, V> map = new HashMap<>();
        for (Tuple<K, V> tuple : tuples) {
            map.put(tuple.first, tuple.second);
        }
        return map;
    }

    static void check(boolean condition, String message, Object... arguments) {
        if (!condition) {
            throw exception(message, arguments);
        }
    }

    static RuntimeException exception(String message, Object... arguments) {
        String finalMessage = String.format(message, arguments);
        LOGGER.error(finalMessage);
        return new RuntimeException(finalMessage);
    }

    static RuntimeException exception(Exception exception, String message, Object... arguments) {
        String finalMessage = String.format(message, arguments);
        LOGGER.error(finalMessage);
        return new RuntimeException(finalMessage, exception);
    }

    static byte[] resourceToByteArray(Resource resource) {
        try {
            return IOUtils.toByteArray(resource.getInputStream());
        } catch (Exception exception) {
            throw exception(exception, "Error converting resource to byte array.");
        }
    }

    static Resource byteArrayToResource(byte[] data) {
        return new ByteArrayResource(data);
    }

    static String buildPath(String... pathParts) {
        return StringUtils.join(pathParts, File.separator);
    }

    static void createFileParents(File file) {
        File parentFile = file.getParentFile();
        if (parentFile != null) {
            parentFile.mkdirs();
        }
    }
}