Kotlin で Async (await) な LINE BOT を書いてみた

SDK は公式の Java SDK がそのまま使える。

1. webhook を受け取る
2. 非同期で getProfile を呼ぶ
3. 完了したら、TextMessage で返す

package com.example

import com.linecorp.bot.client.LineMessagingClient
import com.linecorp.bot.model.event.MessageEvent
import com.linecorp.bot.model.event.message.TextMessageContent
import com.linecorp.bot.model.message.Message
import com.linecorp.bot.model.message.TextMessage
import com.linecorp.bot.spring.boot.annotation.EventMapping
import com.linecorp.bot.spring.boot.annotation.LineMessageHandler
import kotlinx.coroutines.experimental.future.await
import kotlinx.coroutines.experimental.future.future
import org.springframework.boot.SpringApplication
import org.springframework.boot.autoconfigure.SpringBootApplication


@SpringBootApplication
@LineMessageHandler
open class Application(val client: LineMessagingClient) {
    companion object {
        @JvmStatic
        fun main(args: Array<String>) {
            SpringApplication.run(Application::class.java, *args)
        }
    }

    @EventMapping
    fun echoText(event: MessageEvent<TextMessageContent>) = future<Message> {
        val userProfile = client.getProfile(event.source.userId).await();
        return@future TextMessage("${event.message} from ${userProfile.displayName}");
    }
}