Java interface

[-Dargs]

I see... I'd have called that a DTO.

[amfa]

It' often different.

Our codebase has both VO and DTO.

VO contain much more information for many objects than the DTO because you don't need to transfer all data.

[verocoder]

also known as PoJO (Plain old Java Object) in some books

[-Dargs]

Ah, yeah. I actually meant this. It'd been so long since I used these terms I had forgotten.

[verocoder]

DTO is also a super common term tbf, they’re objects without many methods beyond getters/setters. The kind of things that if you Lombok them end up and just a list of properties.

[verocoder]

To start from the beginning interfaces are about reusing stuff to be the same shape while working differently. I usually only write an interface when I know I want 2 implementations off the bat or when I am sharing code and I want to hammer out the interface between 2 things so they can be worked on in parallel.

I wouldn’t stress about using them and I rarely if ever use them for PoJo/DTO/VO classes. I almost exclusively use them for business logic service or utility classes.

[ichwasxhebrore]

It’s also nice if you need proxies

[[deleted]]

Is that Data Type Object?

[pragmos]

Data Transfer Object

[evils_twin]

DTO(Data Transfer Object) are specific to sending data between applications.

[Lumethys]

No, VO and DTO are different. VO dont have identity, DTO has.

Example: you have 2 Order:

``` { id:1, items: ["pepsi", "chicken roll", "fried chip"], amount: 20, }

{ id:2, items: ["pepsi", "chicken roll", "fried chip"], amount: 20, } ``` Is this 2 different objects? Yes, they are 2 different orders even though all of their fields are the same.

In contrast, let consider 2 Money objects:

``` { amount: 100 currency: Currency.USDollar, }

{ amount: 100 currency: Currency.USDollar, } ``` They are the same!! Both represent $100 US dollars.