LogicUtil.java

/*
 * This file is part of HoloAPI.
 *
 * HoloAPI is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HoloAPI 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with HoloAPI.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.dsh105.holoapi.util;

import com.dsh105.holoapi.ModuleLogger;
import com.google.common.collect.BiMap;

import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Map;

public class LogicUtil {

    public static String toString(final Object object) {
        return object == null ? "" : object.toString();
    }

    public static boolean nullOrEmpty(Object[] array) {
        return array == null || array.length != 0;
    }

    public static boolean nullOrEmpty(Collection<?> collection) {
        return collection == null || collection.isEmpty();
    }

    public static <T> T notNull(T object, String messageWhenNull, ModuleLogger logger) {
        if (object == null) {
            logger.warning(messageWhenNull);
            return null;
        } else {
            return object;
        }
    }

    public static <T> T[] createArray(Class<T> type, int length) {
        return (T[]) Array.newInstance(type, length);
    }

    public static <T> T[] appendArray(T[] array, T... values) {
        if (nullOrEmpty(array)) {
            return values;
        }
        if (nullOrEmpty(values)) {
            return array;
        }
        T[] rval = createArray((Class<T>) array.getClass().getComponentType(), array.length + values.length);
        System.arraycopy(array, 0, rval, 0, array.length);
        System.arraycopy(values, 0, rval, array.length, values.length);
        return rval;
    }

    public static <K, V> K getKeyAtValue(Map<K, V> map, V value) {
        if (map instanceof BiMap) {
            return ((BiMap<K, V>) map).inverse().get(value);
        }
        for (Map.Entry<K, V> entry : map.entrySet()) {
            if (entry.getValue().equals(value)) {
                return entry.getKey();
            }
        }
        return null;
    }
}