- The document discusses using Kotlin to build chatbots and provides code samples for building bots using the Telegram and LINE messaging APIs. - It introduces Kotlin as a programming language and covers how to create Telegram and LINE bots using Kotlin with libraries like kotlin-telegram-bot and line-bot-sdk-java. - Code examples are provided for building echo bots that can respond to text messages as well as handle other message types like stickers for both Telegram and LINE bots built with Kotlin.

1. Kotlin
(Shengyou Fan)
Chatbot Meetup #28
2021/03/15
Photo by Phillip Glickman on Unsplash

2. —
•
•
•
SDK
•

3. Kotlin Open Source
JetBrains …
Chatbot

4. 2020 3 Kotlin
!
…
Kotlin …

5. +
—
60
2020
100
2021

6. Kotlin
—
• General-purpose
• Static typing
• OOP + FP
• Developed by
JetBrains
• Open Source
(Apache 2.0)
https://kotlinlang.org/

7. —

8. Kotlin
—
Browser
Kotlin/JS
Server
Kotlin/JVM
iOS
Kotlin/Native
Android
Kotlin/JVM

9. —
•
•
•
•
Email

10. Email
—
•
•
•
IM

11. Kotlin
~

12. —
• IntelliJ IDEA JDKs
• Telegram Bot
• LINE Developer Messaging API
• ngrok

13. IntelliJ IDEA
—
IDE + SDK

14. Telegram Bot
—
@BotFather

15. LINE Developer
—

16. Messaging API
—

17. ngrok
—
# macOS
$ brew install --cask ngrok
# Windows
$ scoop install ngrok

18. "

19. Kotlin Telegram SDK
—
https://github.com/kotlin-telegram-bot/kotlin-telegram-bot

20. Kotlin
—

21. —
repositories {
// ...
maven("https://jitpack.io")
}
dependencies {
// ...
implementation("...kotlin-telegram-bot:telegram:$version")
// ...
}

22. Bot
—
val bot = bot {
token = ...
// ...
}
bot.startPolling()

23. EchoBot
—
bot {
token = ...
dispatch {
text {
bot.sendMessage(
chatId = ChatId.fromId(message.chat.id),
text = text
)
}
}
}

24. —
bot {
// ...
dispatch {
text("ping") {
bot.sendMessage(
chatId = ChatId.fromId(message.chat.id),
text = "..."
)
}
text("markdown") {
val markdownText = "..."
bot.sendMessage(
chatId = ChatId.fromId(message.chat.id),
text = markdownText,
parseMode = ParseMode.MARKDOWN
)
}
}
}

25. —
bot {
// ...
dispatch {
command("greeting") {
val result = bot.sendMessage(
chatId = ChatId.fromId(message.chat.id),
text = "..."
)
result.fold({ /* ... */ }, { /* ... */ })
}
}
}

26. —
bot {
// ...
dispatch {
message(Filter.Sticker) {
// ...
}
newChatMembers {
newChatMembers.forEach {
// ...
}
}
}
}

27. Webhook
—
bot {
// ...
webhook {
url = ...
}
dispatch {
// ...
}
}.startWebhook()
embeddedServer(Netty, port = 8080) {
routing {
post("/...") {
val response = call.receiveText()
bot.processUpdate(response)
call.respond(HttpStatusCode.OK)
}
}
}.start(wait = true)
• Ktor
• ngrok
• webhook
• bot

28. Kotlin LINE SDK
—
https://github.com/line/line-bot-sdk-java

29. Spring Boot
—

30. —
dependencies {
// ...
implementation("...line-bot-spring-boot:$version")
// ...
}

31. Webhook
—
# src/main/resources/application.yml
line.bot:
channel-token: '...'
channel-secret: '...'
handler.path: /callback
• ngrok
• webhook

32. Bot
—
@LineMessageHandler
class LineBotController {
@EventMapping
fun handler(event: Event) {
// ...
}
}

33. EchoBot
—
@LineMessageHandler
class LineBotController {
@EventMapping
fun handleTextMessageEvent(
event: MessageEvent<TextMessageContent>
): Message
{
val originalMessageText = event.message.text
return TextMessage(originalMessageText)
}
}

34. — @LineMessageHandler
class LineBotController(
@Autowired val lineMessagingClient: LineMessagingClient
) {
private val log = ...
@EventMapping
fun handleTextMessageEvent(
event: MessageEvent<TextMessageContent>
) {
when(event.message.text) {
"ping" -> {
lineMessagingClient.replyMessage(
ReplyMessage(
event.replyToken,
listOf(TextMessage("Pong"))
)
).get()
}
}
}
}

35. — @LineMessageHandler
class LineBotController(
@Autowired val lineMessagingClient: LineMessagingClient
) {
private val log = ...
@EventMapping
fun handleStickerMessageEvent(
event: MessageEvent<StickerMessageContent>
) {
val apiResponse = lineMessagingClient.replyMessage(
ReplyMessage(
event.replyToken,
listOf(StickerMessage(
event.message.packageId,
event.message.stickerId)
)
)
).get()
}
}

36. Kotlin

37. —
• Kotlin
• Kotlin
•
• Kotlin Telegram Bot LINE Bot

38. —
• Telegram Bot
- https://github.com/shengyou/kotlin-telegram-bot-sample
• LINE Bot
- https://github.com/shengyou/kotlin-line-bot-sample

39. #
One more thing!

40. Kotlin
—
8:00
Line Telegram

41. https://tw.kotlin.tips
Tips
—
https://tw.intellij.tips

42. —

43. —
Coding
Kraftsman

44. (Shengyou Fan)
shengyou.fan@jetbrains.com
Q&A
—
Kotlin