MultipleBagFetchHqlTest.java

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.test.collection.bag;

import java.util.ArrayList;
import java.util.List;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.OneToMany;
import javax.persistence.Table;

import org.junit.Test;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.loader.MultipleBagFetchException;
import org.hibernate.testing.junit4.BaseCoreFunctionalTestCase;

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

public class MultipleBagFetchHqlTest extends BaseCoreFunctionalTestCase {

	@Override
	protected Class[] getAnnotatedClasses() {
		return new Class[] {
				Post.class,
				PostComment.class,
				Tag.class
		};
	}

	@Test
	public void testMultipleBagFetchHql() throws Exception {

		Session session = openSession();
		Transaction transaction = session.beginTransaction();

		Post post = new Post();
		post.setId( 1L );
		post.setTitle( String.format( "Post nr. %d", 1 ) );
		PostComment comment = new PostComment();
		comment.setId(1L);
		comment.setReview( "Excellent!" );
		session.persist(post);
		session.persist( comment );
		post.comments.add( comment );

		transaction.commit();
		session.close();


		session = openSession();
		session.beginTransaction();

		try {
			post = (Post) session.createQuery(
					"select p " +
							"from Post p " +
							"join fetch p.tags " +
							"join fetch p.comments " +
							"where p.id = :id"
			)
					.setParameter( "id", 1L )
					.uniqueResult();
			fail("Should throw org.hibernate.loader.MultipleBagFetchException: cannot simultaneously fetch multiple bags");
		}
		catch ( IllegalArgumentException expected ) {
			session.getTransaction().rollback();
			// MultipleBagFetchException was converted to IllegalArgumentException
			assertTrue( MultipleBagFetchException.class.isInstance( expected.getCause() ) );
		}
		finally {
			session.close();
		}
	}

	@Entity(name = "Post")
	@Table(name = "post")
	public static class Post {

		@Id
		private Long id;

		private String title;

		@OneToMany(fetch = FetchType.LAZY)
		private List<PostComment> comments = new ArrayList<PostComment>();

		@ManyToMany(fetch = FetchType.LAZY)
		@JoinTable(name = "post_tag",
				joinColumns = @JoinColumn(name = "post_id"),
				inverseJoinColumns = @JoinColumn(name = "tag_id")
		)
		private List<Tag> tags = new ArrayList<Tag>();

		public Post() {
		}

		public Post(Long id) {
			this.id = id;
		}

		public Post(String title) {
			this.title = title;
		}

		public Long getId() {
			return id;
		}

		public void setId(Long id) {
			this.id = id;
		}

		public String getTitle() {
			return title;
		}

		public void setTitle(String title) {
			this.title = title;
		}

		public List<Tag> getTags() {
			return tags;
		}
	}

	@Entity(name = "PostComment")
	@Table(name = "post_comment")
	public static class PostComment {

		@Id
		private Long id;

		private String review;

		public PostComment() {
		}

		public PostComment(String review) {
			this.review = review;
		}

		public Long getId() {
			return id;
		}

		public void setId(Long id) {
			this.id = id;
		}

		public String getReview() {
			return review;
		}

		public void setReview(String review) {
			this.review = review;
		}
	}

	@Entity(name = "Tag")
	@Table(name = "tag")
	public static class Tag {

		@Id
		private Long id;

		private String name;

		public Long getId() {
			return id;
		}

		public void setId(Long id) {
			this.id = id;
		}

		public String getName() {
			return name;
		}

		public void setName(String name) {
			this.name = name;
		}
	}
}