Added koin for dipendency injection

Author: tusan

build.gradle

@@ -1,5 +1,7 @@
 plugins {
     id 'org.jetbrains.kotlin.jvm' version '1.2.71'
+    id "net.ltgt.apt" version "0.10"
+
 }
 
 apply plugin: 'kotlin'
@@ -8,7 +10,10 @@ apply plugin: 'application'
 group 'com.tubelli'
 version '1.0-SNAPSHOT'
 
-ext.ktor_version = '0.9.5'
+ext {
+    ktor_version = '0.9.5'
+    koin_version = '0.9.3'
+}
 
 repositories {
     mavenCentral()
@@ -22,6 +27,12 @@ dependencies {
     compile "io.ktor:ktor-server-netty:$ktor_version"
     compile "io.ktor:ktor-gson:$ktor_version"
 
+    compile "com.google.dagger:dagger:2.17"
+    annotationProcessor 'com.google.dagger:dagger-compiler:2.17'
+
+    compile "org.koin:koin-ktor:$koin_version"
+    compile "org.koin:koin-core:$koin_version"
+
     compile("ch.qos.logback:logback-classic:1.2.3")
 }
 

src/main/kotlin/App.kt

@@ -1,32 +1,29 @@
 import io.ktor.application.Application
-import io.ktor.application.call
 import io.ktor.application.install
 import io.ktor.features.ContentNegotiation
 import io.ktor.gson.gson
-import io.ktor.response.respondText
-import io.ktor.routing.get
-import io.ktor.routing.routing
+import io.ktor.routing.Routing
 import io.ktor.server.engine.embeddedServer
 import io.ktor.server.netty.Netty
-
-private val itemRepository = ItemRepository()
+import org.koin.ktor.ext.inject
+import org.koin.standalone.StandAloneContext.startKoin
 
 fun main(args: Array<String>) {
+    startKoin(listOf(applicationContext))
     embeddedServer(Netty, 8080, module = Application::main).start(wait = true)
 }
 
 fun Application.main() {
+    val itemRepository: ItemRepository by inject()
 
-    routing {
-        install(ContentNegotiation) {
-            gson {
-                setPrettyPrinting()
-            }
-        }
-        get("/") {
-            call.respondText { "Hello from my first ktor service :)" }
+    install(ContentNegotiation) {
+        gson {
+            setPrettyPrinting()
         }
+    }
 
-        itemRouting(itemRepository)
+    install(Routing) {
+        itemsApi(itemRepository)
     }
-}
+}
+

src/main/kotlin/ApplicationContext.kt

@@ -0,0 +1,8 @@
+import java.util.concurrent.CopyOnWriteArrayList
+import java.util.concurrent.atomic.AtomicInteger
+
+val applicationContext = org.koin.dsl.module.applicationContext {
+    bean { ItemRepository() }
+    bean { AtomicInteger() }
+    bean { CopyOnWriteArrayList<Item>() }
+}

src/main/kotlin/DefaultController.kt

@@ -4,39 +4,3 @@ import io.ktor.request.receive
 import io.ktor.response.respond
 import io.ktor.routing.*
 
-fun Route.itemRouting(itemRepository: ItemRepository) {
-    get("/items") {
-        call.respond(itemRepository.getAll())
-    }
-
-    get("/itemRouting/{id}") {
-        call.parameters["id"]?.let { id ->
-            itemRepository.get(id.toInt())?.let { item ->
-                call.respond(item)
-            }
-        }
-        call.respond(HttpStatusCode.NotFound)
-    }
-
-    delete("/itemRouting/{id}") {
-        call.parameters["id"]?.let { id ->
-            itemRepository.remove(id.toInt())
-        }
-
-        call.respond(HttpStatusCode.Accepted)
-    }
-
-    put("/itemRouting") {
-        val item = call.receive<Item>()
-        itemRepository.add(item)
-
-        call.respond(HttpStatusCode.Created)
-    }
-
-    post("/itemRouting") {
-        val item = call.receive<Item>()
-        itemRepository.update(item)
-
-        call.respond(HttpStatusCode.OK)
-    }
-}

src/main/kotlin/ItemRepository.kt

@@ -1,9 +1,10 @@
+import org.koin.standalone.KoinComponent
 import java.util.concurrent.CopyOnWriteArrayList
 import java.util.concurrent.atomic.AtomicInteger
-
-class ItemRepository {
-    private val idCounter = AtomicInteger()
-    private val items = CopyOnWriteArrayList<Item>()
+import org.koin.standalone.inject
+class ItemRepository : KoinComponent {
+    private val idCounter: AtomicInteger by inject()
+    private val items: CopyOnWriteArrayList<Item> by inject()
 
     fun add(i: Item) =
             if (!items.contains(i)) {

src/main/kotlin/itemsApi.kt

@@ -0,0 +1,43 @@
+import io.ktor.application.call
+import io.ktor.http.HttpStatusCode
+import io.ktor.request.receive
+import io.ktor.response.respond
+import io.ktor.response.respondText
+import io.ktor.routing.*
+
+fun Routing.itemsApi(repository: ItemRepository) {
+    get("/") {
+        call.respondText { "Hello from my first ktor service :)" }
+    }
+
+    get("/items") {
+        call.respond(repository.getAll())
+    }
+    get("/itemRouting/{id}") {
+        call.parameters["id"]?.let { id ->
+            repository.get(id.toInt())?.let { item ->
+                call.respond(item)
+            }
+        }
+        call.respond(HttpStatusCode.NotFound)
+    }
+    delete("/itemRouting/{id}") {
+        call.parameters["id"]?.let { id ->
+            repository.remove(id.toInt())
+        }
+
+        call.respond(HttpStatusCode.Accepted)
+    }
+    put("/itemRouting") {
+        val item = call.receive<Item>()
+        repository.add(item)
+
+        call.respond(HttpStatusCode.Created)
+    }
+    post("/itemRouting") {
+        val item = call.receive<Item>()
+        repository.update(item)
+
+        call.respond(HttpStatusCode.OK)
+    }
+}