Java tutorial
/* * This code was written by Bear Giles <bgiles@coyotesong.com> and he * licenses this file to you 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 * * Any contributions made by others are licensed to this project under * one or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. * * 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. * * Copyright (c) 2013 Bear Giles <bgiles@coyotesong.com> */ package com.invariantproperties.project.student.specification; import javax.persistence.criteria.CriteriaBuilder; import javax.persistence.criteria.CriteriaQuery; import javax.persistence.criteria.Predicate; import javax.persistence.criteria.Root; import org.springframework.data.jpa.domain.Specification; import com.invariantproperties.project.student.domain.Student; import com.invariantproperties.project.student.domain.TestRun; import com.invariantproperties.project.student.metamodel.Student_; import com.invariantproperties.project.student.metamodel.TestRun_; /** * JPA Criteria specifications for students. * * @author Bear Giles <bgiles@coyotesong.com> */ public class StudentSpecifications { /** * Creates a specification used to find students with the specified * testUuid. * * @param testRun * @return */ public static Specification<Student> testRunIs(final TestRun testRun) { return new Specification<Student>() { @Override public Predicate toPredicate(Root<Student> root, CriteriaQuery<?> query, CriteriaBuilder cb) { Predicate p = null; if (testRun == null || testRun.getUuid() == null) { p = cb.isNull(root.<Student_>get("testRun")); } else { p = cb.equal(root.<Student_>get("testRun").<TestRun_>get("uuid"), testRun.getUuid()); } return p; } }; } }