Java 15 records

Java records

Java 15 introduced the record — they reduce the hassle of creating POJOs immensely.

The test

With the test code, we create an object Painting and assign Dimensions, testing the width corresponds with the test data:

import org.example.record.Dimensions;
import org.example.record.Painting;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class PaintingTest {
    @Test
    void testGetDimensions() {
        var painting = new Painting(new Dimensions(12, 22));
        assertEquals(22, painting.dimensions().width());
    }
}

The code

Painting.java

package org.example.record;

public record Painting(Dimensions dimensions) {}

Dimensions.java*

package org.example.record;

public record Dimensions(int height, int width) {}

Summed up

With records, boilerplate class declarations, getters, equals and hashcode are replaced by a single record class declaration.

For more information, see Oracle’s Java 15 Java Language Updates.

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* Ignoring that we haven’t specified a unit such as centimetre/inch