Dereferencer.java

package com.ciandt.techgallery.utils;

import com.google.common.base.Function;
import com.google.common.collect.Lists;

import com.googlecode.objectify.Ref;

import java.util.List;

public class Dereferencer {
  public static class Func<T> implements Function<Ref<T>, T> {
    public static Func<Object> INSTANCE = new Func<Object>();

    @Override
    public T apply(Ref<T> ref) {
      return deref(ref);
    }
  }

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

  @SuppressWarnings({"unchecked", "rawtypes"})
  public static <T> List<T> deref(List<Ref<T>> reflist) {
    return Lists.transform(reflist, (Func) Func.INSTANCE);
  }
}