com.centretown.planets.server.dao.objectify.Deref.java Source code

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Here is the source code for com.centretown.planets.server.dao.objectify.Deref.java

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/**
 * Copyright 2013 ArcBees Inc.
 *
 * 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.centretown.planets.server.dao.objectify;

import java.util.Collection;
import java.util.Map;
import java.util.Set;

import com.google.common.collect.Sets;
import com.googlecode.objectify.Key;
import com.googlecode.objectify.Ref;

public class Deref {
    public static <T> T deref(Ref<T> ref) {
        return ref == null ? null : ref.get();
    }

    public static <T> T deref(Ref<T> ref, final Class<?>... groups) {
        return ref == null ? null : ofy().load().group(groups).key(ref.key()).now();
    }

    public static <T> Set<T> deref(Collection<Ref<T>> reflist) {
        return deref(reflist, (Class<?>[]) null);
    }

    public static <T> Set<T> deref(Collection<Ref<T>> reflist, Class<?>... groups) {
        if (reflist == null) {
            return null;
        }
        return Sets.newHashSet(values(reflist, groups).values());
    }

    public static <T> Map<Key<T>, T> values(Collection<Ref<T>> reflist, Class<?>... groups) {
        if (reflist == null) {
            return null;
        }
        if (groups == null || groups.length <= 0) {
            return ofy().load().values(reflist);
        }
        return ofy().load().group(groups).values(reflist);
    }

    private final static Ofy ofy() {
        return OfyService.ofy();
    }
}