Java tutorial
/* * Copyright 2008-2019 the original author or authors. * * 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 * * https://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 org.springframework.data.domain; import org.springframework.lang.Nullable; /** * Simple interface for entities. * * @param <ID> the type of the identifier * @author Oliver Gierke * @author Christoph Strobl */ public interface Persistable<ID> { /** * Returns the id of the entity. * * @return the id. Can be {@literal null}. */ @Nullable ID getId(); /** * Returns if the {@code Persistable} is new or was persisted already. * * @return if {@literal true} the object is new. */ boolean isNew(); }