Java 17 — Record Classes

Record is a special kind of class, designed to hold data with less boilerplate code. It’s a more concise way to define classes that only store data, removing the need for writing getters, setters, toString(), equals(), and hashCode() methods manually.

Git Link: https://github.com/prakashbtech87/PrakashJavaRepository/tree/main/src/main/java/com/prakash/version/java17/record

Here’s a comparison between your regular class and a Record class:

Regular class:

package com.prakash.version.java17.record.normalclass;

import java.util.Objects;

/**
 * @author prakashkaruppusamy
 */
class Animal {
    String name;
    String animalType;
    long runningSpeed;

    // Constructor
    public Animal(String name, String animalType, long runningSpeed) {
        this.name = name;
        this.animalType = animalType;
        this.runningSpeed = runningSpeed;
    }

    // Getters
    public String getName() {
        return name;
    }

    public String getAnimalType() {
        return animalType;
    }

    public long getRunningSpeed() {
        return runningSpeed;
    }

    // toString() method
    @Override
    public String toString() {
        return "Animal{" +
                "name='" + name + '\'' +
                ", animalType='" + animalType + '\'' +
                ", runningSpeed=" + runningSpeed +
                '}';
    }

    // hashCode and equals methods
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Animal animal = (Animal) o;
        return runningSpeed == animal.runningSpeed &&
                name.equals(animal.name) &&
                animalType.equals(animal.animalType);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, animalType, runningSpeed);
    }
}

Record class

package com.prakash.version.java17.record;

/**
 * @author prakashkaruppusamy
 */
public record Animal(String name, String animalType, long runningSpeed) {
}

How Records make life easier:

1. Less Boilerplate: You don’t need to manually write getters, setters, toString(), equals(), or hashCode(). All of these are automatically provided by the Record class.

2. Immutability: Once you create a Record object, its state cannot change. This makes it simpler to work with, especially in multithreading scenarios.

3. Conciseness: You write less code, which means fewer bugs and easier maintenance.

package com.prakash.version.java17.record;

/**
 * @author prakashkaruppusamy
 */
public class Main {
    public static void main(String[] args) {
        Animal lion = new Animal("Lion", "Mammal", 50);

        // Accessing data
        System.out.println("Animal Name: " + lion.name());
        System.out.println("Animal Type: " + lion.animalType());
        System.out.println("Running Speed: " + lion.runningSpeed());

        // Using toString() automatically
        System.out.println(lion); // Output: Animal[name=Lion, animalType=Mammal, runningSpeed=50]
    }
}

In summary, Records simplify your code by automatically generating most of the repetitive tasks involved in defining data-holding classes.