diff --git a/persistence-modules/java-jpa-3/README.md b/persistence-modules/java-jpa-3/README.md
new file mode 100644
index 0000000000..01fdf05b53
--- /dev/null
+++ b/persistence-modules/java-jpa-3/README.md
@@ -0,0 +1,3 @@
+## JPA in Java
+
+This module contains articles about the Java Persistence API (JPA) in Java.
diff --git a/persistence-modules/java-jpa-3/pom.xml b/persistence-modules/java-jpa-3/pom.xml
new file mode 100644
index 0000000000..da18ae3046
--- /dev/null
+++ b/persistence-modules/java-jpa-3/pom.xml
@@ -0,0 +1,83 @@
+
+
+ 4.0.0
+ java-jpa-3
+ java-jpa-3
+
+
+ com.baeldung
+ persistence-modules
+ 1.0.0-SNAPSHOT
+
+
+
+
+ org.hibernate
+ hibernate-core
+ ${hibernate.version}
+
+
+ org.hibernate
+ hibernate-jpamodelgen
+ ${hibernate.version}
+
+
+ com.h2database
+ h2
+ ${h2.version}
+
+
+
+
+ javax.persistence
+ javax.persistence-api
+ ${javax.persistence-api.version}
+
+
+
+
+ org.eclipse.persistence
+ eclipselink
+ ${eclipselink.version}
+ runtime
+
+
+ org.postgresql
+ postgresql
+ ${postgres.version}
+ runtime
+
+
+ org.assertj
+ assertj-core
+ ${assertj.version}
+ test
+
+
+
+
+
+
+ org.apache.maven.plugins
+ maven-compiler-plugin
+ ${maven-compiler-plugin.version}
+
+ -proc:none
+
+
+
+
+
+
+ 5.4.14.Final
+ 2.7.4
+ 42.2.5
+ 2.2
+ 3.11.1
+ 3.5.1
+ 3.3.3
+ 3.0.0
+
+
+
diff --git a/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByBusinessKey.java b/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByBusinessKey.java
new file mode 100644
index 0000000000..3fe858936a
--- /dev/null
+++ b/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByBusinessKey.java
@@ -0,0 +1,53 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.*;
+
+@Entity
+public class EqualByBusinessKey {
+
+ @Id
+ @GeneratedValue(strategy = GenerationType.AUTO)
+ private Long id;
+
+ private String email;
+
+ public EqualByBusinessKey() {
+ }
+
+ public Long getId() {
+ return id;
+ }
+
+ public void setId(Long id) {
+ this.id = id;
+ }
+
+ public String getEmail() {
+ return email;
+ }
+
+ public void setEmail(String email) {
+ this.email = email;
+ }
+
+ @Override
+ public int hashCode() {
+ return java.util.Objects.hashCode(email);
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj) {
+ return true;
+ }
+ if (obj == null) {
+ return false;
+ }
+ if (obj instanceof EqualByBusinessKey) {
+ if (((EqualByBusinessKey) obj).getEmail() == getEmail()) {
+ return true;
+ }
+ }
+ return false;
+ }
+}
diff --git a/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualById.java b/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualById.java
new file mode 100644
index 0000000000..cebfb5fcec
--- /dev/null
+++ b/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualById.java
@@ -0,0 +1,55 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.*;
+
+@Entity
+public class EqualById {
+
+ @Id
+ @GeneratedValue(strategy = GenerationType.AUTO)
+ private Long id;
+
+ private String email;
+
+ public EqualById() {
+ }
+
+ public Long getId() {
+ return id;
+ }
+
+ public void setId(Long id) {
+ this.id = id;
+ }
+
+ public String getEmail() {
+ return email;
+ }
+
+ public void setEmail(String email) {
+ this.email = email;
+ }
+
+
+ @Override
+ public int hashCode() {
+ final int prime = 31;
+ int result = 1;
+ result = prime * result + ((id == null) ? 0 : id.hashCode());
+ return result;
+ }
+
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj) {
+ return true;
+ }
+ if (obj == null) {
+ return false;
+ }
+ if (obj instanceof EqualById) {
+ return ((EqualById) obj).getId().equals(getId());
+ }
+ return false;
+ }
+}
diff --git a/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByJavaDefault.java b/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByJavaDefault.java
new file mode 100644
index 0000000000..b312845b61
--- /dev/null
+++ b/persistence-modules/java-jpa-3/src/main/java/com/baeldung/jpa/equality/EqualByJavaDefault.java
@@ -0,0 +1,36 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.*;
+
+@Entity
+public class EqualByJavaDefault implements Cloneable{
+
+ @Id
+ @GeneratedValue(strategy = GenerationType.AUTO)
+ private Long id;
+
+ private String email;
+
+ public EqualByJavaDefault() {
+ }
+
+ public Long getId() {
+ return id;
+ }
+
+ public void setId(Long id) {
+ this.id = id;
+ }
+
+ public String getEmail() {
+ return email;
+ }
+
+ public void setEmail(String email) {
+ this.email = email;
+ }
+
+ public Object clone() throws CloneNotSupportedException {
+ return super.clone();
+ }
+}
diff --git a/persistence-modules/java-jpa-3/src/main/resources/META-INF/persistence.xml b/persistence-modules/java-jpa-3/src/main/resources/META-INF/persistence.xml
new file mode 100644
index 0000000000..28a929f912
--- /dev/null
+++ b/persistence-modules/java-jpa-3/src/main/resources/META-INF/persistence.xml
@@ -0,0 +1,25 @@
+
+
+
+ org.hibernate.jpa.HibernatePersistenceProvider
+ com.baeldung.jpa.equality.EqualByJavaDefault
+ com.baeldung.jpa.equality.EqualById
+ com.baeldung.jpa.equality.EqualByBusinessKey
+ true
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/persistence-modules/java-jpa-3/src/main/resources/logback.xml b/persistence-modules/java-jpa-3/src/main/resources/logback.xml
new file mode 100644
index 0000000000..2527fea245
--- /dev/null
+++ b/persistence-modules/java-jpa-3/src/main/resources/logback.xml
@@ -0,0 +1,15 @@
+
+
+
+
+ %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} -
+ %msg%n
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/equality/EqualityUnitTest.java b/persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/equality/EqualityUnitTest.java
new file mode 100644
index 0000000000..03ac11b6fd
--- /dev/null
+++ b/persistence-modules/java-jpa-3/src/test/java/com/baeldung/jpa/equality/EqualityUnitTest.java
@@ -0,0 +1,74 @@
+package com.baeldung.jpa.equality;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class EqualityUnitTest {
+
+ private static EntityManagerFactory factory;
+ private static EntityManager entityManager;
+
+ @BeforeClass
+ public static void setup() {
+ factory = Persistence.createEntityManagerFactory("jpa-h2-equality");
+ entityManager = factory.createEntityManager();
+ }
+
+ @Test
+ public void givenObjectBasedEquality_whenUsingEquals_thenEqualIsBasedOnInstance() throws CloneNotSupportedException {
+ EqualByJavaDefault object1 = new EqualByJavaDefault();
+ EqualByJavaDefault object2 = new EqualByJavaDefault();
+
+ object1.setEmail("test.user@domain.com");
+
+ entityManager.getTransaction().begin();
+ entityManager.persist(object1);
+ entityManager.getTransaction().commit();
+
+ object2 = (EqualByJavaDefault) object1.clone();
+
+ Assert.assertNotEquals(object1, object2);
+ Assert.assertEquals(object1.getId(), object2.getId());
+ Assert.assertEquals(object1.getEmail(), object2.getEmail());
+ }
+
+ @Test
+ public void givenIdBasedEquality_whenUsingEquals_thenEqualIsBasedOnId() {
+ EqualById object1 = new EqualById();
+ EqualById object2 = new EqualById();
+
+ object1.setEmail("test.user.1@domain.com");
+ object2.setEmail("test.user.2@domain.com");
+
+ entityManager.getTransaction().begin();
+ entityManager.persist(object1);
+ entityManager.getTransaction().commit();
+
+ object2.setId(object1.getId());
+
+ Assert.assertEquals(object1, object2);
+ Assert.assertEquals(object1.getId(), object2.getId());
+ Assert.assertNotEquals(object1.getEmail(), object2.getEmail());
+ }
+
+ @Test
+ public void givenBusinessKeyBasedEquality_whenUsingEquals_thenEqualIsBasedOnBusinessKey() {
+ EqualByBusinessKey object1 = new EqualByBusinessKey();
+ EqualByBusinessKey object2 = new EqualByBusinessKey();
+
+ object1.setEmail("test.user@test-domain.com");
+ object2.setEmail("test.user@test-domain.com");
+
+ entityManager.getTransaction().begin();
+ entityManager.persist(object1);
+ entityManager.getTransaction().commit();
+
+ Assert.assertEquals(object1, object2);
+ Assert.assertNotEquals(object1.getId(), object2.getId());
+ }
+}