equals() and hashCode() in Java

Always override hashCode() when you override equals() to maintain the contract between them.

Source Code

public class Person {
    private String name;
    private int age;

    // Constructor, getters and setters

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Person)) return false;
        Person person = (Person) o;
        return age == person.age && name.equals(person.name);
    }

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