From ce79066afc6b20c1d2d9dbd09dc8cc34e096f300 Mon Sep 17 00:00:00 2001
From: Bhaskar Ghosh Dastidar <dastidar.bhaskar@gmail.com>
Date: Sat, 6 May 2023 21:58:20 +0530
Subject: [PATCH] [BAEL-6253] record equals hashcode (#13958)

* [BAEL-6253] records equals and hashcode

* [BAEL-6253] records equals and hashcode

* [BAEL-6253] records equals and hashcode test case

---------

Co-authored-by: Bhaskar <bhaskar.dastidar@freshworks.com>
---
 core-java-modules/core-java-records/pom.xml   | 32 +++++++++++++++++++
 .../baeldung/equalshashcoderecords/Movie.java | 26 +++++++++++++++
 .../equalshashcoderecords/Person.java         |  5 +++
 .../CustomRecordEqualsHashCode.java           | 30 +++++++++++++++++
 core-java-modules/pom.xml                     |  1 +
 5 files changed, 94 insertions(+)
 create mode 100644 core-java-modules/core-java-records/pom.xml
 create mode 100644 core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Movie.java
 create mode 100644 core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Person.java
 create mode 100644 core-java-modules/core-java-records/src/test/java/com/baeldung/equalshashcoderecords/CustomRecordEqualsHashCode.java

diff --git a/core-java-modules/core-java-records/pom.xml b/core-java-modules/core-java-records/pom.xml
new file mode 100644
index 0000000000..ed9a36fc14
--- /dev/null
+++ b/core-java-modules/core-java-records/pom.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>core-java-records</artifactId>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>16</source>
+                    <target>16</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source>19</maven.compiler.source>
+        <maven.compiler.target>19</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+</project>
\ No newline at end of file
diff --git a/core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Movie.java b/core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Movie.java
new file mode 100644
index 0000000000..e94638e8b5
--- /dev/null
+++ b/core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Movie.java
@@ -0,0 +1,26 @@
+package com.baeldung.equalshashcoderecords;
+
+import java.util.Objects;
+
+record Movie(String name, Integer yearOfRelease, String distributor) {
+
+@Override
+public boolean equals(Object other) {
+    if (this == other) {
+        return true;
+    }
+    if (other == null) {
+        return false;
+    }
+    Movie movie = (Movie) other;
+    if (movie.name.equals(this.name) && movie.yearOfRelease.equals(this.yearOfRelease)) {
+        return true;
+    }
+    return false;
+}
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, yearOfRelease);
+    }
+}
diff --git a/core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Person.java b/core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Person.java
new file mode 100644
index 0000000000..7bfd8ae741
--- /dev/null
+++ b/core-java-modules/core-java-records/src/main/java/com/baeldung/equalshashcoderecords/Person.java
@@ -0,0 +1,5 @@
+package com.baeldung.equalshashcoderecords;
+
+public record Person(String firstName, String lastName, String SSN, String dateOfBirth) {
+};
+
diff --git a/core-java-modules/core-java-records/src/test/java/com/baeldung/equalshashcoderecords/CustomRecordEqualsHashCode.java b/core-java-modules/core-java-records/src/test/java/com/baeldung/equalshashcoderecords/CustomRecordEqualsHashCode.java
new file mode 100644
index 0000000000..074886304f
--- /dev/null
+++ b/core-java-modules/core-java-records/src/test/java/com/baeldung/equalshashcoderecords/CustomRecordEqualsHashCode.java
@@ -0,0 +1,30 @@
+package com.baeldung.equalshashcoderecords;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+import org.junit.Test;
+
+public class CustomRecordEqualsHashCode {
+    @Test
+    public void givenTwoRecords_whenDefaultEquals_thenCompareEquality() {
+        Person robert = new Person("Robert", "Frost", "HDHDB223", "2000-01-02");
+        Person mike = new Person("Mike", "Adams", "ABJDJ2883", "2001-01-02");
+        assertNotEquals(robert, mike);
+    }
+
+    @Test
+    public void givenTwoRecords_hashCodesShouldBeSame() {
+        Person robert = new Person("Robert", "Frost", "HDHDB223", "2000-01-02");
+        Person robertCopy = new Person("Robert", "Frost", "HDHDB223", "2000-01-02");
+        assertEquals(robert.hashCode(), robertCopy.hashCode());
+    }
+
+    @Test
+    public void givenTwoRecords_whenCustomImplementation_thenCompareEquality() {
+        Movie movie1 = new Movie("The Batman", 2022, "WB");
+        Movie movie2 = new Movie("The Batman", 2022, "Dreamworks");
+        assertEquals(movie1, movie2);
+        assertEquals(movie1.hashCode(), movie2.hashCode());
+    }
+}
diff --git a/core-java-modules/pom.xml b/core-java-modules/pom.xml
index 6f3aec8c3a..91f0dbfc28 100644
--- a/core-java-modules/pom.xml
+++ b/core-java-modules/pom.xml
@@ -141,6 +141,7 @@
         <module>core-java-uuid</module>
         <module>pre-jpms</module>
         <module>core-java-collections-maps-6</module>
+        <module>core-java-records</module>
     </modules>
 
     <dependencyManagement>