Auto-configuration

Understand the idea

Boot considers classpath dependencies, configuration properties, and existing beans. A template engine dependency can trigger template configuration. Defining a supported custom bean can replace a corresponding default. This mechanism configures the framework rather than generating your application features.

A concrete example

Thymeleaf on classpath
→ template engine configuration
MongoDB starter + URI
→ MongoDB connection infrastructure

In the application

The labs provide their source classes and properties while Boot sets up the surrounding web and data infrastructure.

Having the server start does not prove the remote database connection or CRUD workflow works.

See it in a working stage

• Stage 13: connect the Stage 12 application to MongoDB Atlas

Related concepts

• Starter dependency
• Spring Boot
• Spring bean