Doorgaan naar hoofdcontent

Learing good Code styles

Yesterday I had one of those days where all of a sudden I'm shown my code isn't as good as it should be.
Oh dear.

So, something to learn, because they were right.

Two things:
Static methods
Static methods are 'horrible'. After discussing about the why, finally a good argument came up: They inhibit extension! You cannot override them, and usually it is a sign of functional programming style. That may not be bad per se, but being able to override functions is a good thing. So:
BE CAREFUL TO MARK METHODS STATIC. USUALLY, IT CAN BE DONE BETTER.

Strategies
Strategies are cool. However, I tend to push into that direction. That my not be necessarily bad, but strategies are only for compile-time decisions. Ther is a difference between implementing classes which are injected, and thereby selected at 'compile time', and actual runtime by using, say an abstract factory to determine which strategy to use for the current run.

So, note to self: only name an interface a 'strategy' when there is an abstract factory

Labels

Labels:

Reacties

Een reactie posten

Populaire posts van deze blog

Spring's conditional annotation with properties

Spring has a nice @Conditional annotation, to have the option to have beans be available in the context depending a specific condition (Of course, this can also be realized by using @Configuration objects, but that's a different post). Ideally, we'd have the option to have a condition evaluate to true or false depending on a property. Sadly, Spring does not support that out of the box. Googling and looking around gives a partial solution, but the complete one here, so we won't forget: /** * Components annotated with ConditionalOnProperty will be registered in the spring context depending on the value of a * property defined in the propertiesBeanName properties Bean. */ @Target({ ElementType.TYPE, ElementType.METHOD }) @Retention(RetentionPolicy.RUNTIME) @Conditional(OnPropertyCondition.class) public @interface ConditionalOnProperty { /** * The name of the property. If not found, it will evaluate to false. */ String value(); /** * if the p...
Een reactie posten
Meer lezen

OSGI insights without sonar

So I was on a project without sonar. Oh my. Well, it was an OSGI project, so the problems couldn't be that bad, right? But how good were they (and what things were bad?) I found Stan4j , a code analysis tool for eclipse, which draws nice graphs and can handle osgi pretty well it seems. Now I can see that dependencies/bundle names aren't properly aligned (even though OSGI doesn't complain), etc.
Een reactie posten
Meer lezen

JPA and transactions

So I was working with JPA and transactions. Consider the following: In bean 1, with implicit TX 1, managed entities are loaded/created,and returned in bean 2, with implicit TX 2, entities are modified in bean 3, with NO TX, bean 1 is called, and the results are passed to bean 2. and bean 4 is similar to bean 3, but with it's own transaction, TX3 What happens when bean 3 finishes: are the entities updated? What happens when bean 4 finishes, are the entities updated? The answer to this is simple; entities are managed through a persistance context. That context is tied to the transaction. So in bean 2, there is a difference. When called from bean 3, it runs in a different transaction then bean 1, and thus a different persistance context, and thus the entities are not managed 'by this transaction'.When called from bean 4, it all runs in the same transaction, TX3, and the results are persisted.
Een reactie posten
Meer lezen