hey Channel. I am accustomed to inject beans usin...

# spring

[Alexandre A Barbosa]

hey Channel.

I am accustomed to inject beans using Springboot doing, for example:

@Autowired
private AccountMapper mapper;

I want to avoid of instantiate a HttpClient builder every time in my @Component class. Instead of do val client = HttpClient.newBuilder().build() every time, please let me know how to inject it using Kotlin.

[Sam]

@Configuration
class HttpClientConfiguration {
    @Bean
    fun httpClient(): HttpClient = HttpClient.newBuilder().build()
}

[Davio]

Just be careful, because this would create a singleton bean which is shared by all of your code and this may mess with things if the client does not work well when it's shared

[Alexandre A Barbosa]

thank you Guys!

[Alexandre A Barbosa]

hey @Sam
Considering this example, how to use it?
Maybe in my Component Class by constructor?

[Sam]

Yep, once you have declared the configuration class, you will be able to autowire the HTTP client inside other component classes, including via constructor injection 👍

[Davio]

You don't need the Autowired annotation, just put it into the constructor and Spring will inject it

[Alexandre A Barbosa]

Awesome. Yeah!
It’s hard forget Java/Spring and think in Kotlin, I am learning Kotlin and trying to apply these concepts related to Functional Program.

[Davio]

Well it works the same in Java, this is more due to Spring than Kotlin

[Sam]

There is a way to declare beans in functional style in Kotlin but I haven’t seen it used much. Can’t find the docs 🤔

[Sam]

Example: https://github.com/sdeleuze/spring-kotlin-functional/blob/master/src/main/kotlin/functional/Beans.kt

[Alexandre A Barbosa]

Thank you for this awesome information guys.
I did two Kotlin courses but I am still struggling with specific points… like how to convert ByteArray to Byte[] and how to do the same as we can do using Java StreamAPI but in Kotlin I am struggling yet

[Alexandre A Barbosa]

Thank you for this tip about the injection

[Sam]

Off-topic, but for ByteArray -> Byte[] use toTypedArray() 😉

[Alexandre A Barbosa]

hey @Sam

[Alexandre A Barbosa]

please, could you clarify that?

[Alexandre A Barbosa]

I tried to use this toTypedArray() but I didn’t manage to

[Sam]

A ByteArray in Kotlin is equivalent to a java primitive byte[] array. You can call .toTypedArray() on it to convert it to a Kotlin Array<Byte>, which is equivalent to a boxed Java Byte[] array.

[Alexandre A Barbosa]

I will try again here. Thank you