How safe would it be to use functional-java to add closures to a Java production project?

Question

I would love to use closures in Java. I have read that they may or may not make it into Java 7. But an open-source project called functional-java has implemented functional features including closures.

How safe would it be to use such a library in an enterprise production app?

Is there a better way to add closures to Java currently?

Infusionism

You could try using scala or clojur instead – Siracusa

Answer 1

Closures will definitely not make it into Java 7, due to a lack of consensus around a single implementation. See here.

The Functional Java library is thoroughly tested and actively developed. If you browse the source you will see that it's just simple bog-standard Java, and there's not a lot that could go wrong. I know at least one mission-critical enterprise app that uses it in production. This application has more than a million users.

Go for it.

Disallow

Answer 2

Functional Java does not requires that you use closures -- the source compiles with any Java 1.5 compiler. Functional Java is far more complete than Google collections and just happens to allow you to use it well with BGGA.

Hope this helps.

Incalculable

Answer 3

I think you are looking at this issue from the wrong perspective.

I would love to use closures in Java. ... How safe would it be to use such a library in an enterprise production app?

Your decision making on what technology to use in an enterprise production app should be based on what is going to be best for the enterprise in the long term. You should be asking questions like:

• Is adding the technology going to significantly improve the app from the standpoint of functionality?
• What are the risks to the current project?
• Does the technology claim to be "production ready"?
• Is the technology supported. Is it likely to still be supported in 5 to 10 years time?
• If you leave the company, is someone else going to take over maintaining your code?
• What are the training / recruiting implications of using the technology?

In general, statements like "I would love to use Xxx" should have no place in enterprise decision making. (There are counter-examples; e.g. startups that bet the company on some new technology, but the real success rate is ... umm ... open to speculation.)

To sum it all up, if you are building enterprise production apps, you need to be conservative, and resist the temptation to use shiny new technology "for fun". Try to think like an IT manager.

Meilhac

Answer 4

If you are looking for a lighter solution to have closures in plain Java check out the lambdaj project:

http://code.google.com/p/lambdaj/

Angi

Lambdaj was, the last time I tested it, pretty slow. Honestly, I was really disappointed by this because I was hoping to make use of it. – Fiberboard

Which version did you test? In which feature did you find it slow? Of course you have to pay something for the use of proxy and reflection, but the performance loss is quite well documented and in the biggest part of the cases is very reasonable. – Angi

I wish I could answer your questions, but I didn't make not of much when I tested it. I seem to recall is was 3-5x slower for the use case I was testing it on... and that that case was something I'd use it for (ie, close to something I'm doing in production code), but not more than that. I truly wish I could be more specific, but it was a couple months ago and I didn't take much in the way of notes. – Fiberboard

Answer 5

BGGA is still a prototype implementation, not sure how comfortable you are putting prototype code into production. check out google collections it gets you closer to the goal albeit more verbosely

Leyte

Interesting but it doesn't seem to have anything like closures - just collections. – Infusionism

Functional Java does not require BGGA, but does support it. – Disallow

Google Collections does have a Function<A, B> type, and most of their collections implement a functor. Functional Java's collections implement functors as well as monads, cofunctors and comonads. – Disallow

yes, depends on what you are shooting for . Trying to do full fledged functional programming in java would be clumsy and inelegant at best. Google collection nicely fits that gap for collections in java way – Leyte

Answer 6

Too old question to answer. Here we have lambdas in java8 to make your life easier.

Unknit