CODEWITHSUNDEEP
javanaming-conventions
roundcrisis
roundcrisis

Reputation: 17795

Java Interface, AbstractClass and Enum naming convention

We are having this discussion in our team about code conventions for Java for:

I'm basically trying to put my personal preferences aside :) so reasons to back up one or other convention are very welcome.

Upvotes: 32

Views: 23291

Answers (9)

ION Renalyte
ION Renalyte

Reputation: 13

Here's convetion used in my DEV team in ION.

Interface

interface IMyInterface

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abstract class MyAbstract

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enum EMyEnumeration

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Upvotes: -2

JodaStephen
JodaStephen

Reputation: 63365

From my blog:

  • Foo - The interface ultimately defines the concept, so it should have the best name.
  • AbstractFoo - An abstract implementation intended to be used as the base of a hierarchy of classes.
  • BaseFoo - An implementation intended to be used as the base of a hierarchy of classes, where the base class could be used on its own if necessary.
  • DefaultFoo - A "default" implementation that would be appropriate for the majority of typical use cases.
  • SimpleFoo - A "simple" implementation with no unexpected functionality, perhaps as an example or as a mock. A simple POJO would be a good "simple" implementation.
  • {Descriptive}Foo - Other implementations should describe what makes them unique.

The blog also discusses reasons against some of the other names.

Upvotes: 22

merxbj
merxbj

Reputation: 381

Regarding the interfaces I personaly like:

Fooable

Upvotes: 2

Kissaki
Kissaki

Reputation: 9217

About interfaces:

I prefer IFoo because it’s a talking name, telling you it is an inferface right away. Second, for modules etc. where you do an interface for just one class, the class often has the same name as the interface. Then you can use Foo extends IFoo. Otherwise, well, you’d have to find a name. Or use FooInterface or whatever …

java.util.list as stated uses Foo. This is no problem as classes with different concepts implement it, thus already suggesting a different name (ArrayList, LinkedList …). I’m not quite sure if I really would prefer IList there. Dunno … :P

Upvotes: 1

Michael Borgwardt
Michael Borgwardt

Reputation: 346260

No special conventions.

Having special naming conventions for these kinds of classes is basically a form of Hungarian notation (the bad kind): the information it gives you is already present in the syntax and is usually made easily available by IDEs e.g. when you hover over the name. Putting it into the name itself is pointless and ugly.

Class names should simply describe the class's role as well as possible. This can lead to "natural" naming conventions - a very good example is the Java convention of naming interfaces with an -able suffix (Iterable, Comparable) - but I don't want to imagine the result if it were universally enforced and List, Map, etc. had to follow it.

Upvotes: 5

jrharshath
jrharshath

Reputation: 26583

interfaces: Foo

Reason: Your code must not need to know that they are dealing with an interface. Writing 'IFoo' does just that. Instead, Foo makes it clear that 'Foo' is generic, and the object behind it may be a 'NumFoo' or a 'StrFoo'. The code really need not care.

abstract classes: AbstractFoo

Reason: your code is never going to use this class directly. You will always subclass this class to make any classes that are used by other code. So it must be amply clear to a programmer that the class is an abstract one. And what better way to name it Abstract! Places where you need to use references of type AbstractFoo, you should reconsider using an interface instead. (Ofcourse, this is not possible in C++)

Enums: FooType or FooEnum. Personally, FooType is better because Type relates more easily to the "real world" that Enum does.

Cheers!

Upvotes: 19

dfa
dfa

Reputation: 116304

My convention:

  • interface: Foo
  • abstract: it depends FooAdaptor or AbstractFoo or BaseFoo
  • enum: Foo or Foos

I really dislike using I in interface names or even FooInterface:

 interface FooInterface {

is like writing:

 class FooClass {

or even:

 abstract class AbstractFooClass {

it is simply prolix.

Upvotes: 3

cletus
cletus

Reputation: 625007

My convention:

  • Interface: Foo;
  • Abstract: AbstractFoo;
  • Enum: usually Foo but in some circumstances FooType.

IFoo is very .Net, not Java. FooInterface I've never seen used.

Upvotes: 2

Jon Skeet
Jon Skeet

Reputation: 1499800

In Java: Foo, AbstractFoo and Foo - although AbstractFoo could just be Foo.

Evidence:

  • java.util.List (interface)
  • java.util.AbstractList (abstract class)
  • java.util.Formatter.BigDecimalLayoutForm (enum)

For the interface part, see the Naming Conventions section of the Java Coding Conventions document. It doesn't talk about enums and abstract classes though.

Upvotes: 35

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