PurpleJS – An alternative to Node.js for Java projects

PurpleJS – An alternative to Node.js for Java projects(webagility.com)

81 points by thousande 9 years ago | 49 comments

I particularly don't find the problem it solves appealing. The power of Node comes specifically from its everything async programming model, Javascript is just a detail.

So what's the point in taking away the good part, and keep the cumbersome one? If you just want to program a Synchronous server in the JVM,just stick to Java.

_pmf_ 9 years ago | |

> If you just want to program a Synchronous server in the JVM,just stick to Java.

And if you want to program an asynchronous server on the JVM in Java, all of the major and minor servers also support an asynchronous model (you merely lose the ability to program against the Servlet API, which pre-3 was bound to threads).

There's no reason at all to bring JS in for asynchronous behavior.

sourcesmith 9 years ago | | |

There is also Vert.x which runs on the JVM but is event driven and asynchronous (as well as providing a reactive API) and supports JavaScript (http://vertx.io/docs/vertx-core/js/) as one of its languages.

cel1ne 9 years ago | |

I hope you don't mean the JVM by "the cumbersome part". It think is unparalleled in performance, garbage-collection, general dev-ops and monitoring capabilities.

You can run many different languages on it, all nicely contained within the virtual machine.

As far as I know Twitter replaced their Ruby/Rails with Code on top of the JVM for these reasons.

Also I don't think it's good to religiously stick to async/"just one thread" and sync/"one thread for everything". The most performant answer depends on the real world scenario and almost always lies somewhere in between.

boggydepot 9 years ago | | |

I think he meant the js not java. Question about node js, So async model is the good part, js is the bad part, why use js then?

my123 9 years ago | | |

The JVM is nowhere near as flexible as the CLR.

amelius 9 years ago | |

> The power of Node comes specifically from its everything async programming model, Javascript is just a detail.

I don't agree. The power of Node comes from being able to run the same code on the browser and the server (without transpiling performance penalties).

smashed 9 years ago |

How does this relate to Nashorn?

With something like Avatar-JS [1] you can even run some NodeJS apps without modifications on the JVM.

[1] https://avatar-js.java.net

desdiv 9 years ago | |

It's built on top of Nashorn[1].

[1] https://github.com/purplejs/purplejs/search?utf8=%E2%9C%93&q...

wentoodeep 9 years ago | | |

Ok so no android. Next.

illicium 9 years ago | |

See also Trireme [1], an implementation of Node.js 0.10.32 on the JVM, using Rhino.

[1] https://github.com/apigee/trireme

iamleppert 9 years ago |

Why do people think async code is complicated and keep trying to replace it?

I think there are just people who will never understand or fully grok the beauty, power and simplicity of functional programming and will always seek to replace it. I feel sorry for them.

skrebbel 9 years ago | |

> Why do people think async code is complicated and keep trying to replace it?

As usual, @munificentbob explains it best: http://journal.stuffwithstuff.com/2015/02/01/what-color-is-y...

fredliu 9 years ago |

Isn't use case proposed by PurpleJS covered by Vert.x already? Or am I missing anything?

stenrs 9 years ago | |

Vert.x is similar. PurpleJS tries to make development of your webapps easier by combining the require-js model and a "sinatra"-way of developing rest endpoints.

dewiz 9 years ago |

I wonder if LucasArts is happy with that logo :-) The image and the font brought up some good memories.

https://en.m.wikipedia.org/wiki/Day_of_the_Tentacle

https://images-na.ssl-images-amazon.com/images/I/514Q95XGV8L...

jsuperman 9 years ago | |

They have actually stated on Twitter that the mascot is inspired by the DOTT character and the Java character (Duke): https://twitter.com/purple_js/status/732660360348631040

agentgt 9 years ago |

I have seen several similar things that essentially use existing Java libraries or the libraries themselves offer it (Javascript).

* jooby [1]

* Vert.x [2]

* Rapidoid (I can't find the exact link where JS was used) [3]

I'm just not entirely sure why you would trade a language that is generally much safer for one that is known to be problematic at scale particularly since Java 8 has lambdas so you can do callback async style if you like. I mean I suppose you could use typescript but at that point why not stick with Node and if you need JVM stuff just make some sort of microservice to access it from Node.

If it is a learning thing than (as Java is complicated) than Clojure is far better option (I'm always amazed how easy it is to learn any Lisp as syntax becomes a non issue).

[1]: http://jooby.org/

[2]: http://vertx.io/

[3]: http://www.rapidoid.org/

diegorbaquero 9 years ago |

Interesting offer, would be great to have some benchmarks comparison to see the value of it. Do you happen to have some?

jsuperman 9 years ago | |

I haven't seen any benchmarks yet, but the framework is actually originally the core engine of the web os / cms Enonic XP. Worth checking out:

https://discuss.enonic.com/t/purplejs-an-alternative-to-node...

https://enonic.com/

stenrs 9 years ago | |

No, sorry, no benchmarks yet. The main focus until now has been to speed up the development process. Right now it's pretty slick when it comes to reloading of resources on-the-fly when changed.

tracker1 9 years ago |

I'm just not sure I see the value... and in the end, not sure it will work out any better than the DLR attempts with .Net... It's interesting, just not sure I see the value. The Java runtime is about 60mb to download, then the extras for this... vs Node's runtime download under 14mb with a similar amount of library downloads for a given project.

That doesn't include the disconnect from the rest of the JS ecosystem which has centered around npm at this point (at least for the package repository itself, baring the yarn front end).

andrea_s 9 years ago | |

Perhaps that's closer to ClearScript (https://clearscript.codeplex.com/) in the .NET environment - although ClearScript has a broader area of application and supports multiple engines.

cheriot 9 years ago |

This could be pretty cool. So in theory, all the Java, Scala, etc servers out there can wire up an isomorphic single page app without calling out to a Node process.

Once the docs are written... https://github.com/purplejs/purplejs/wiki/Embedding

premium-concern 9 years ago | |

Or you use Scala and Scala.js and just get things done.

stenrs 9 years ago | |

Sorry about that. The embedded mode is not yet documented, but I can certainly help you with embedding into existing systems.

__derek__ 9 years ago |

This reminded me of Nodyn[1], a Node-compatible JVM implementation, which it appears is no longer actively developed.

[1]: https://github.com/nodyn/nodyn#notice

stenrs 9 years ago | |

No, Nodyn tried to be fully compatible with NodeJs. PurpleJS is just an alternative - the scope is not to be fully compatible. Also Nodyn has it's own implementation of Javascript. PurpleJS uses Nashorn as the Javascript engine.

ilaksh 9 years ago |

I didn't see any mention of Rhino. Does he know that existed (exists?)?

hibbelig 9 years ago | |

This uses Nashorn to execute the Javascript.

ilaksh 9 years ago | | |

Oh ok so thats the new version then or rewrite? Just seems like he thinks its a new thing even though its been around for many years.

gfosco 9 years ago |

Why don't any of the examples use Java?... Even the examples on GitHub, none of it looks any different than a Node.js project.

partycoder 9 years ago | |

An oversimplified way to describe node.js is: javascript bindings for libuv.

purpleJS would be javascript bindings for some Java framework.

skanga 9 years ago | |

Check here: https://github.com/purplejs/purplejs-examples/tree/master/sy...

mgkimsal 9 years ago | |

Because it's still javascript, just running on JVM instead of... v8?

At least, that's my read of the project.

gfosco 9 years ago | | |

Ok, that's part of it. This line from the page is what gets me, "create server applications with Javascript but access and use Java libraries" and I think an example of that is very important.

johnhenry 9 years ago |

Is it correct to say that this is like JRuby, but with JavaScript in place of Ruby?

PedroBatista 9 years ago | |

More like "This is like Sinatra running on the equivalent of JRuby"

lisivka 9 years ago |

Does it use Rhino (to compile JS into bytecode)?

stenrs 9 years ago | |

No, it's using Nashorn which is bundled with Java 1.8+. It compiles Javascript into JVM bytecode as Rhino, but it's more performant.

lisivka 9 years ago | | |

Thanks. Last time I looked at JS in Sun Java, it was in interpreter mode only due to license issues, so I always bundled Rhino with my projects to be able to precompile JS code, so it will run faster. But now performance of Nashorn is pretty impressive: https://blogs.oracle.com/nashorn/entry/nashorn_performance_w... .

kjsingh 9 years ago |

simple question - can it work with npm dependencies out of box?

boggydepot 9 years ago | |

not out of the box, but the js vm used is based on webkit. for pure js deps, it can probably use them.

but maven repo is what you have out of the box which contains all (mostly) the libraries for java