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// Copyright 2008 Google 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.google.gwtorm.client;
/**
* Generic type for an entity key.
*
* <p>Although not required, entities should make their primary key type implement this interface,
* permitting traversal up through the containment hierarchy of the entity keys.
*
* @param <P> type of the parent key. If no parent, use {@link Key} itself.
*/
public interface Key<P extends Key<?>> {
/**
* Get the parent key instance.
*
* @return the parent key; null if this entity key is a root-level key.
*/
public P getParentKey();
@Override
public int hashCode();
@Override
public boolean equals(Object o);
/** @return the key, encoded in a string format . */
@Override
public String toString();
/** Reset this key instance to represent the data in the supplied string. */
public void fromString(String in);
}