ManyToManyBidirectionalTest.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.userguide.associations;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.ManyToMany;

import org.hibernate.annotations.NaturalId;
import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;

import org.junit.Test;

import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;

/**
 * @author Vlad Mihalcea
 */
public class ManyToManyBidirectionalTest extends BaseEntityManagerFunctionalTestCase {

	@Override
	protected Class<?>[] getAnnotatedClasses() {
		return new Class<?>[] {
				Person.class,
				Address.class,
		};
	}

	@Test
	public void testLifecycle() {
		doInJPA( this::entityManagerFactory, entityManager -> {
			//tag::associations-many-to-many-bidirectional-lifecycle-example[]
			Person person1 = new Person( "ABC-123" );
			Person person2 = new Person( "DEF-456" );

			Address address1 = new Address( "12th Avenue", "12A", "4005A" );
			Address address2 = new Address( "18th Avenue", "18B", "4007B" );

			person1.addAddress( address1 );
			person1.addAddress( address2 );

			person2.addAddress( address1 );

			entityManager.persist( person1 );
			entityManager.persist( person2 );

			entityManager.flush();

			person1.removeAddress( address1 );
			//end::associations-many-to-many-bidirectional-lifecycle-example[]
		} );
	}

	//tag::associations-many-to-many-bidirectional-example[]
	@Entity(name = "Person")
	public static class Person {

		@Id
		@GeneratedValue
		private Long id;

		@NaturalId
		private String registrationNumber;
		@ManyToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE})
		private List<Address> addresses = new ArrayList<>();

		public Person() {
		}

		public Person(String registrationNumber) {
			this.registrationNumber = registrationNumber;
		}

		public List<Address> getAddresses() {
			return addresses;
		}

		public void addAddress(Address address) {
			addresses.add( address );
			address.getOwners().add( this );
		}

		public void removeAddress(Address address) {
			addresses.remove( address );
			address.getOwners().remove( this );
		}

		@Override
		public boolean equals(Object o) {
			if ( this == o ) {
				return true;
			}
			if ( o == null || getClass() != o.getClass() ) {
				return false;
			}
			Person person = (Person) o;
			return Objects.equals( registrationNumber, person.registrationNumber );
		}

		@Override
		public int hashCode() {
			return Objects.hash( registrationNumber );
		}
	}

	@Entity(name = "Address")
	public static class Address {

		@Id
		@GeneratedValue
		private Long id;

		private String street;

		@Column(name = "`number`")
		private String number;

		private String postalCode;

		@ManyToMany(mappedBy = "addresses")
		private List<Person> owners = new ArrayList<>();

		public Address() {
		}

		public Address(String street, String number, String postalCode) {
			this.street = street;
			this.number = number;
			this.postalCode = postalCode;
		}

		public Long getId() {
			return id;
		}

		public String getStreet() {
			return street;
		}

		public String getNumber() {
			return number;
		}

		public String getPostalCode() {
			return postalCode;
		}

		public List<Person> getOwners() {
			return owners;
		}

		@Override
		public boolean equals(Object o) {
			if ( this == o ) {
				return true;
			}
			if ( o == null || getClass() != o.getClass() ) {
				return false;
			}
			Address address = (Address) o;
			return Objects.equals( street, address.street ) &&
					Objects.equals( number, address.number ) &&
					Objects.equals( postalCode, address.postalCode );
		}

		@Override
		public int hashCode() {
			return Objects.hash( street, number, postalCode );
		}
	}
	//end::associations-many-to-many-bidirectional-example[]
}