Spring Boot — Production-Grade Java Apps with Minimum Fuss

What Spring Boot Does

• Auto-configuration — detect classpath and wire beans automatically
• Embedded server — Tomcat, Jetty, or Undertow built in (no WAR deploy)
• Starters — spring-boot-starter-web, -data-jpa, -security, -actuator
• Actuator — health, metrics, info, env, configprops endpoints
• Spring Data JPA — repository interfaces auto-implement CRUD
• Spring Security — auth, authorization, OAuth2, CORS, CSRF
• Spring MVC — annotation-driven REST controllers
• Spring WebFlux — reactive non-blocking stack
• Profiles — dev/test/prod environment configuration
• GraalVM native — compile to native binary (Spring AOT)

Architecture

Spring IoC container manages beans. Auto-configuration inspects the classpath and conditionally registers beans. Starters bring in curated dependency sets. Actuator exposes operational endpoints. Configuration via application.yml / application.properties with profiles.

Self-Hosting

# Build executable JAR
./mvnw package -DskipTests
java -jar target/demo-0.0.1-SNAPSHOT.jar

# Docker
FROM eclipse-temurin:21-jre
COPY target/*.jar app.jar
ENTRYPOINT ["java", "-jar", "app.jar"]

# Native image
./mvnw -Pnative native:compile
./target/demo    # ~30ms startup

Key Features

• Auto-configuration
• Embedded server
• 80+ official starters
• Spring Data (JPA, MongoDB, Redis, Elasticsearch)
• Spring Security
• Spring Actuator
• Spring WebFlux (reactive)
• GraalVM native compilation
• Profiles for environment config
• Excellent documentation and guides

Comparison

FAQ

Q: Spring Boot vs Spring Framework? A: Spring Framework is the underlying IoC + AOP + MVC. Spring Boot is the layer on top: auto-configuration, starters, embedded server, so you don't write XML and complex bean configs.

Q: Slow startup? A: JVM startup is indeed slow (1-5s). Solution: Spring AOT + GraalVM Native Image can drop startup time to 30-50ms.

Q: Compared to Quarkus? A: Quarkus is optimized for cloud-native (faster startup, smaller RSS); Spring Boot has the biggest ecosystem and most enterprise experience. Most medium-to-large teams still choose Spring Boot.

Sources

• Docs: https://docs.spring.io/spring-boot/docs
• GitHub: https://github.com/spring-projects/spring-boot
• License: Apache 2.0