org.springframework.cloud.gcp.data.datastore.core.mapping.DiscriminatorValue Maven / Gradle / Ivy

/*
 * Copyright 2017-2019 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.cloud.gcp.data.datastore.core.mapping;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Annotation for subclasses in an inheritance hierarchy that matches a value in a
 * discrimination field in the parent class.
 *
 * @author Chengyuan Zhao
 */
@Documented
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface DiscriminatorValue {

	/**
	 * The value that corresponds to entities of the annotated subclass stored in the
	 * Datastore Kind belonging to the parent class.
	 * @return the value that corresponds to the annotated subclass.
	 */
	String value();
}