Record

It is possible to add as many class types as necessary for a Java program. But for clarity of the code, and ease of maintenance, using records to reduce code size is possible.

With the record keyword, we can create a class with multiple fields. An optional constructor, with simplified syntax, can also be added for validation.

Example

This Java program defines 3 different records, and then creates one instance of each of them. Records can be defined at the class level, or locally within a method.

public class Program {

    // Created in main.
    record ShopEntry (String name, int cost) {}

    public static void main(String[] args) {
        // Part 1: create new entry from class-level record.
        ShopEntry s = new ShopEntry("shoes", 200);
        System.out.println(s);

        // Part 2: use local record and create an instance of it.
        record ShopEntry2 (String name, int size) {}
        ShopEntry2 s2 = new ShopEntry2("pants", 40);
        System.out.println(s2);

        // Part 3: use local record with simplified constructor.
        record ShopEntry3 (String name, int id) {
            ShopEntry3 {
                name = name.toUpperCase();
                id = id;
            }
        }
        ShopEntry3 s3 = new ShopEntry3("hat", 30);
        System.out.println(s3);
    }
}
ShopEntry[name=shoes, cost=200]
ShopEntry2[name=pants, size=40]
ShopEntry3[name=HAT, id=30]

Some notes

For complicated types with many uses in a program, a class is probably worth creating. But if a type is only used in one place, and is simple, a record is a good option.

Much like records in other object-oriented programming languages, the records in Java provide a lightweight, low-syntax class type. They can be used like classes in most ways.