AbstractHasKey.java

/*
 */

package st.voo.tick.entity.util;

import com.googlecode.objectify.Key;
import com.googlecode.objectify.Ref;

/**
 * A simple way to remove some boilerplate from some entity.
 */
abstract public class AbstractHasKey<T extends HasKey<T>> implements HasKey<T>
{
	/* (non-Javadoc)
	 * @see st.voo.tick.entity.util.HasKey#getRef()
	 */
	@Override
	public Ref<T> getRef() {
		return Ref.create(getKey());
	}

	/* (non-Javadoc)
	 * @see st.voo.tick.entity.util.HasKey#equivalent(com.googlecode.objectify.Key)
	 */
	@Override
	public boolean equivalent(Key<T> key) {
		return getKey().equals(key);
	}

	/* (non-Javadoc)
	 * @see st.voo.tick.entity.util.HasKey#equivalent(com.googlecode.objectify.Ref)
	 */
	@Override
	public boolean equivalent(Ref<T> ref) {
		return getKey().equivalent(ref);
	}

}

HasKey.java

/*
 */

package st.voo.tick.entity.util;

import com.googlecode.objectify.Key;
import com.googlecode.objectify.Ref;


/**
 * Defines a common interface for entities to expose their key
 */
public interface HasKey<T extends HasKey<T>>
{
	/** Gets the key for the entity, duh */
	Key<T> getKey();

	/** Gets the ref version. Might need to rename this to ref() to avoid javabeans signature. */
	Ref<T> getRef();

	/** @return true if this entity is key-equivalent */
	boolean equivalent(Key<T> key);

	/** @return true if this entity is key-equivalent */
	boolean equivalent(Ref<T> ref);
}