Messenger Bot in Spring Boot: A Complete Step-by-Step Tutorial

The tutorial use ngrok to develop messenger bot in spring boot.

Create Messenger Bot in db developer:
- follow step with Reference 1
Messenger4j sample code in Spring boot:
- git clone sample code:
  git clone https://github.com/messenger4j/messenger4j-spring-boot-quickstart-template.git
- create Spring boot project:
  - create Spring start project in Maven。
  - Copy src,.gitignore,pom.xml and replace those files in Spring boot project. Then Run Maven->update project
  - set up application.properties:
    - messenger4j.appSecret = find the secret in Dashboard
    - messenger4j.verifyToken = create random string by youself
    - messenger4j.pageAccessToken = find this from messenger -> setting -> Page Access Token.
  - set up webhooks:
    - Callback URL:Use ngrok to create https://XXX/callback
    - Verify Token: th same as the random string in application.properties
    - Subscription Fields: messages, messaging_postbacks, messaging_optins, message_deliveries, message_reads, messaging_account_linking, message_echoes.
  - Select the App for subscribed page:
    ☆★ if you’re not subscribed, the App will not give you response anymore.☆★

Result: