Specification.java

/*
 * Copyright 2008-2017 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
 *
 *      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 org.springframework.data.jpa.domain;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;

/**
 * Specification in the sense of Domain Driven Design.
 * 
 * @author Oliver Gierke
 * @author Thomas Darimont
 * @author Krzysztof Rzymkowski
 */
public interface Specification<T> {

	/**
	 * Creates a WHERE clause for a query of the referenced entity in form of a {@link Predicate} for the given
	 * {@link Root} and {@link CriteriaQuery}.
	 * 
	 * @param root
	 * @param query
	 * @return a {@link Predicate}, may be {@literal null}.
	 */
	Predicate toPredicate(Root<T> root, CriteriaQuery<?> query, CriteriaBuilder cb);
}