Реализации на Kotlin

Builder

Общая реализация на языке Kotlin

Реализация класса машины и ее компонентов

Car

class Car(
    val body: Body,
    val engine: Engine,
    val suspension: Suspension
)

Body

abstract class Body(val bodyType: String)

class SedanBody(bodyType: String) : Body(bodyType)

Engine

abstract class Engine(val capacity: Double)

class InternalCombustionEngine(capacity: Double) : Engine(capacity)

Suspension

abstract class Suspension(val type: String)

class AirSuspension(type: String): Suspension(type)

Реализация Builder и Director

IBuilder

interface IBuilder {
    fun withBody(body: Body): IBuilder
    fun withEngine(engine: Engine): IBuilder
    fun withSuspension(suspension: Suspension): IBuilder
    fun build(): Car
}

CamryBuilder

class CamryBuilder : IBuilder {
    private var body: Body = SedanBody("sedan")
    private var engine: Engine = InternalCombustionEngine(2.5)
    private var suspension: Suspension = AirSuspension("mono-cylinder")

    override fun withBody(body: Body): CamryBuilder {
        this.body = body
        return this
    }

    override fun withEngine(engine: Engine): CamryBuilder {
        this.engine = engine
        return this
    }

    override fun withSuspension(suspension: Suspension): CamryBuilder {
        this.suspension = suspension
        return this
    }

    override fun build(): Car {
        return Car(
            body = body,
            engine = engine,
            suspension = suspension,
        )
    }
}

Director

class Director(private val builder: IBuilder) {
    fun create(): Car = builder
        .withEngine(InternalCombustionEngine(3.5))
        .build()
}

fun main() {
    val director = Director(CamryBuilder())
    val camry = director.create()

    println(
        "Director created camry! " +
                "Body: ${camry.body.bodyType}, " +
                "engine: ${camry.engine.capacity}, " +
                "suspension: ${camry.suspension.type}"
    )
}