Dynamically inject class in spring

Question

I want to inject a class dynamically based on the argument of my method call

I`ve try use AspectJ and different annotations of Spring

I need a solution like that:

@Component
class MyUseCase(private val spi: MySpiPort) {

    fun myAction() {
        spi.doSomething("myId")
    }
}

interface Injectable

interface MySpiPort : Injectable {
    fun doSomething(id: String)
}


class MyProxyClass {

    //will intercept all Injectable
    fun resolver(id: String): MySpiPort {
        if(id == "myId"){
            //inject MyFirstImpl
        }else{
            //inject MySecondImpl
        }
        TODO("not implemented")
    }

}

@Component
class MyFirstImpl : MySpiPort {
    override fun doSomething(id: String) {
        TODO("not implemented") 
    }
}

@Component
class MySecondImpl : MySpiPort {
    override fun doSomething(id: String) {
        TODO("not implemented")
    }
}

I expect inject just a common interface of the implementations, I don't want inject in MyUseCase Class a FactoryBean Class or something like that.

I think you need to implement strategy pattern. This link will help you [Strategy pattern with spring beans](https://stackoverflow.com/questions/17629761/strategy-pattern-with-spring-beans) — Shailesh Chandra, Oct 20 '19 at 16:09

score 2 · Accepted Answer · answered Oct 20 '19 at 15:46

2

You can leverage Spring's Conditional injection. Please refer https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#beans-java-conditional

answered Oct 20 '19 at 15:46

Elisha Ebenezer

57
6

how do i get argument passed in runtime in my method to use in @Conditional – Pedro Henrique Oct 20 '19 at 16:10
If you have a finite set of values, you can very well use the Conditionals. Otherwise not – Elisha Ebenezer Oct 20 '19 at 21:14

Dynamically inject class in spring

1 Answers1