| Time |
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Nick |
Message |
| 00:41 |
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sivoais joined #sourcefu |
| 00:51 |
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sivoais joined #sourcefu |
| 01:01 |
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sivoais joined #sourcefu |
| 10:10 |
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pdurbin joined #sourcefu |
| 11:28 |
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tumdedum joined #sourcefu |
| 12:53 |
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pdurbin |
interesting chatter about desugaring Scala for comprehensions around 24:45 http://javaposse.com/java-posse-452 |
| 13:15 |
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sulky joined #sourcefu |
| 16:58 |
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pdurbin |
http://www.reactivemanifesto.org via https://github.com/michbarsinai/PlayfulEye/blob/master/app/controllers/Application.scala |
| 17:01 |
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pdurbin |
and https://github.com/michbarsinai/PlayfulEye/blob/master/app/controllers/Examples.scala |
| 17:06 |
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semiosis |
scala. bleh. |
| 17:27 |
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pdurbin |
semiosis: not a fan? |
| 17:28 |
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semiosis |
right |
| 17:29 |
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pdurbin |
why? |
| 17:31 |
|
semiosis |
learning scala just made me appreciate java more |
| 17:31 |
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pdurbin |
:) |
| 17:32 |
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semiosis |
and i wonder if, long term, java will evolve to the point where scala is irrelevant |
| 18:45 |
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aditsu |
hi, how do people organize business logic and various services in a java application? |
| 18:57 |
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pdurbin |
aditsu: command pattern |
| 18:57 |
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semiosis |
aditsu: http://en.wikipedia.org/wiki/Domain-driven_design |
| 18:58 |
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aditsu |
pdurbin: haven't heard of that one |
| 19:00 |
|
aditsu |
from the wikipedia article, it pretty much looks like the Runnable interface... |
| 19:00 |
|
semiosis |
?!?! |
| 19:00 |
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aditsu |
I mean this article: http://en.wikipedia.org/wiki/Command_pattern |
| 19:00 |
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semiosis |
oh |
| 19:01 |
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pdurbin |
aditsu: see how we import a bunch of command.impl here: https://github.com/IQSS/dataverse/blob/master/src/main/java/edu/harvard/iq/dataverse/api/Dataverses.java |
| 19:01 |
|
pdurbin |
the idea is that you put your business logic in the command |
| 19:01 |
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aditsu |
semiosis: domain-driven design sounds good, but everything I've seen so far about fails to explain it before I fall asleep |
| 19:01 |
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pdurbin |
and then call the command from either an api or a gui |
| 19:02 |
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aditsu |
I'm looking for the practical application of the concepts... what kind of classes to write and how to access them |
| 19:02 |
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semiosis |
aditsu: DDD is fundamentally about having rich domain entities, instead of a complex service layer |
| 19:03 |
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semiosis |
aditsu: so for example, if we want to add a photographer to a campaign, we call campaign.addPhotographer(photog) instead of campaignService.addPhotographerToCampaign |
| 19:03 |
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semiosis |
then your services become thinner and more comprehensible |
| 19:03 |
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semiosis |
since you build a language around your domain objects |
| 19:04 |
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aditsu |
semiosis: so basically adding business logic to the model classes? |
| 19:05 |
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semiosis |
well kinda |
| 19:05 |
|
semiosis |
it's about having model classes that closely model your domain |
| 19:06 |
|
semiosis |
the business logic still goes in the service layer, but it's less complex because it relies on the rich domain objects |
| 19:09 |
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aditsu |
pdurbin: so you have a separate class for each action you want to do? seems a bit overkill |
| 19:10 |
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aditsu |
semiosis: how do you organize the service layer? |
| 19:12 |
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semiosis |
tbh we dont really have a service layer :) |
| 19:12 |
|
semiosis |
our two main java apps are a rest api and a batch processor |
| 19:13 |
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semiosis |
rest apis are essentially CRUD, so the business logic is externalized to the caller |
| 19:14 |
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semiosis |
the batch processor is built with camel and is organized into operations that perform a specific task (resize, apply watermark, etc) which an upload is routed through |
| 19:15 |
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aditsu |
well, what does the rest api do? just access a database? |
| 19:16 |
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semiosis |
database, file storage, and queues |
| 19:16 |
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semiosis |
what little bit of business logic we have is right in the api endpoints |
| 19:16 |
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aditsu |
those are also a kind of services, right? how do you access them? |
| 19:16 |
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aditsu |
in terms of organizing the code |
| 19:18 |
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semiosis |
well there's a thin repository layer in front of the db which just executes queries or does basic CRUD |
| 19:18 |
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semiosis |
also a small client class for the queue (amazon sqs & s3) |
| 19:20 |
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aditsu |
right, do you use static methods? singletons? factory methods? dependency injection? how do you get access to those services from the classes that receive the requests? |
| 19:20 |
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semiosis |
spring for d/i |
| 19:21 |
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aditsu |
alright, in case of DI, I have a problem... my page classes need to be serializable, but I don't want to serialize services (even if I could) |
| 19:22 |
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aditsu |
how can I inject things and avoid serializing them? |
| 19:23 |
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semiosis |
what framework are you using? |
| 19:23 |
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aditsu |
wicket |
| 19:24 |
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aditsu |
and I'd rather avoid a big DI framework for now |
| 19:24 |
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semiosis |
not familiar with wicket |
| 19:25 |
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aditsu |
well, I would have a similar problem if I used servlets for example |
| 19:25 |
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aditsu |
oh, maybe not |
| 19:25 |
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aditsu |
ah, HttpServlet is serializable |
| 19:27 |
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semiosis |
i thought we used frameworks so we didnt have to deal with serialization directly |
| 19:27 |
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semiosis |
http://wicket.apache.org/learn/examples/helloworld.html doesnt mention serializable |
| 19:27 |
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aditsu |
I don't deal with serialization directly, but the framework does |
| 19:28 |
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aditsu |
WebPage implements Serializable |
| 19:30 |
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semiosis |
so, whats the problem? |
| 19:32 |
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aditsu |
the problem is I don't want to serialize injected service objects |
| 19:32 |
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semiosis |
that's a desire, not a problem :) |
| 19:32 |
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semiosis |
i mean, why would you have to do that? |
| 19:32 |
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semiosis |
WebPage should not be a service object |
| 19:32 |
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semiosis |
that's my impression at least |
| 19:33 |
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semiosis |
like i said, not familiar with wicket |
| 19:34 |
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aditsu |
let me rephrase: wicket serializes and deserializes pages in some circumstances; if I inject an object into a page, it will normally be not serializable, so serialization of the page fails |
| 19:36 |
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semiosis |
ah |
| 19:37 |
|
semiosis |
there must be a wicket way to handle that |
| 19:37 |
|
semiosis |
perhaps an annotation you can add or superclass you can extend so wicket can serialize your stuff |
| 19:37 |
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aditsu |
so you're saying I should use DI, and just find the way wicket gets around that problem |
| 19:38 |
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semiosis |
in jax-rs for example you use the JAXB annotation @XmlRootElement on your value classes (transfer objects) then jax-rs will automatically serialize them |
| 19:38 |
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semiosis |
seems like you'd run into this with or without DI |
| 19:39 |
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aditsu |
well, not if I use some static methods here and there :p |
| 19:40 |
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semiosis |
if you say so. doesnt make sense to me, but thats ok |
| 19:42 |
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aditsu |
I mean, if I can get an object by calling a static method, it doesn't become part of the class, so it doesn't affect serialization |
| 19:42 |
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aditsu |
however, it's making the code quite messy |
| 19:43 |
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semiosis |
right, di keeps things clean |
| 19:43 |
|
semiosis |
have you tried using transitive on the injected property? |
| 19:43 |
|
semiosis |
transient |
| 19:43 |
|
aditsu |
I thought about it, but then it would need to be re-injected upon deserialization |
| 19:44 |
|
semiosis |
hmmm, maybe you need another layer |
| 19:45 |
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aditsu |
anyway, apparently people have solved the problem by using some kind of serializable proxies |
| 19:45 |
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semiosis |
so your value objects (like WebPage) dont have injected properties |
| 19:45 |
|
aditsu |
currently they don't |
| 19:46 |
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aditsu |
well, I'm not sure if pages can count as value objects |
| 19:46 |
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aditsu |
they're more like controllers |
| 19:46 |
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semiosis |
i'm so confused |
| 19:46 |
|
semiosis |
and have to get back to work |
| 19:46 |
|
semiosis |
sorry i cant be more help |
| 19:47 |
|
aditsu |
you already helped, thanks a lot :) sorry to keep you |
| 19:49 |
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aditsu |
if DI is the way to go, I should look into this more |
| 19:56 |
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tumdedum joined #sourcefu |
| 20:09 |
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aditsu |
yeah.. wicket has support for guice, and creates serializable dynamic proxies when injecting... I guess that means I have to use interfaces for injection |
| 20:10 |
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aditsu |
it also supports spring, but I'd rather go with guice |
| 20:10 |
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aditsu |
(well, I'd rather code the injection myself, but this is getting complicated) |
| 20:21 |
|
semiosis |
there's basic DI in java now |
| 20:21 |
|
semiosis |
http://docs.oracle.com/javaee/7/tutorial/doc/cdi-basic.htm |
| 20:21 |
|
semiosis |
i think it's based on guice |
| 20:21 |
|
semiosis |
or similar |
| 20:24 |
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pdurbin |
yeah, CDI |
| 20:24 |
|
pdurbin |
"Contexts and Dependency Injection" |
| 20:27 |
|
aditsu |
anyway, I'm not switching to DI just yet, but refactoring the code and organizing some service classes (with instance methods) |
| 20:28 |
|
semiosis |
aditsu: you might also want to check out lombok if you haven't heard of it... http://projectlombok.org/ |
| 20:28 |
|
semiosis |
i can't imagine how I ever got along before lombok |
| 20:29 |
|
semiosis |
if this doesn't convince you, nothing will: http://projectlombok.org/features/Data.html |
| 20:31 |
|
aditsu |
the lombok guy is using "yava" :) |
| 20:33 |
|
aditsu |
semiosis: seems nice, but I'm not sure how much I need it |
| 20:33 |
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aditsu |
this is all annotation processor stuff, right? |
| 20:36 |
|
semiosis |
i guess you dont really *need* it, but it does make life a lot easier |
| 23:33 |
|
pdurbin |
aditsu: ask me in a few months if it's overkill. I'm still getting used to it. :) |
