How to "Unresolved reference error: DefaultHeaders" in kotlin

Question

This is my code based on the quick start guild on ktor.io ( https://ktor.io/quickstart/quickstart/gradle.html )

package blog

import io.ktor.application.*
import io.ktor.http.*
import io.ktor.response.*
import io.ktor.routing.*
import io.ktor.server.engine.*
import io.ktor.server.netty.*

import org.jetbrains.ktor.features.CallLogging


fun Application.main() {
    install(DefaultHeaders)
    install(CallLogging)
    install(Routing) {
        get("/") {
            call.respondText("My Example Blog2", ContentType.Text.Html)
        }
    }
}

When I run gradle build , I got these errors:

e: /Users/antkong/dev/poc/kotlin/src/main/kotlin/BlogApp.kt: (10, 22): Unresolved reference: ktor

e: /Users/antkong/dev/poc/kotlin/src/main/kotlin/BlogApp.kt: (14, 13): Unresolved reference: DefaultHeaders e:

e: /Users/antkong/dev/poc/kotlin/src/main/kotlin/BlogApp.kt: (15, 13): Unresolved reference: CallLogging

Here is my build.gradle file

group 'Example'
buildscript {
    ext.kotlin_version = '1.3.61'
    ext.ktor_version = '1.3.0'

    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

apply plugin: 'java'
apply plugin: 'kotlin'
apply plugin: 'idea'
apply plugin: 'application'

mainClassName = 'io.ktor.server.netty.EngineMain' 

sourceCompatibility = 1.8
compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
}

kotlin {
}

repositories {
    jcenter()
    mavenCentral()
}

dependencies {
    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
    compile "io.ktor:ktor-server-netty:$ktor_version"
    compile "ch.qos.logback:logback-classic:1.2.3"
    testCompile group: 'junit', name: 'junit', version: '4.12'
}

How I can fix these errors?

Answer 1

These artifacts are in another package, your import should look like this:

import io.ktor.application.*
import io.ktor.features.CallLogging
import io.ktor.features.DefaultHeaders
import io.ktor.http.*
import io.ktor.response.*
import io.ktor.routing.*