Java Spring Boot Guide
· By Saurabh Editorial · Java
Build production-grade services with Spring Boot — configuration, DI, data, and testing.
Why Spring Boot?
Core building blocks
Building a REST API
Dependency injection
Data access
Configuration and profiles
Production essentials
Spring Boot turns the Spring ecosystem from a verbose XML adventure into a convention-over-configuration framework. Add a starter, write a class, and you have a production-grade service in minutes.
Spring wires components by type. Mark classes with @Service, @Repository, or @Component and inject them via constructor parameters. Constructor injection is the recommended pattern — it makes dependencies explicit and testable.
Spring Data JPA gives you repository interfaces. Declare a method like findByEmail(String email) and Spring generates the query. Drop to JPQL or native SQL with @Query when you need control.
- @SpringBootApplication — the entry point with auto-configuration.
- Starters — curated dependency bundles (web, data-jpa, security, actuator).
- Auto-configuration — sensible defaults you can override.
- Embedded server — Tomcat, Jetty, or Undertow built in.
- Actuator — health, metrics, and ops endpoints.
- Annotate a class with @RestController.
- Map endpoints with @GetMapping, @PostMapping, etc.
- Bind path and query params with @PathVariable / @RequestParam.
- Validate request bodies with @Valid + Jakarta Validation.
- Return DTOs — never expose entities directly.
- application.yml / .properties for settings.
- @ConfigurationProperties for type-safe binding.
- Profiles (dev, staging, prod) to swap config sets.
- Externalize secrets via env vars or Vault.
- Actuator endpoints behind auth for ops visibility.
- Structured logging with Logback + JSON encoder.
- Distributed tracing via Micrometer + OpenTelemetry.
- Graceful shutdown and readiness probes for k8s.