Spring Boot Java Framework

Spring Boot is an extension of the Spring Framework that simplifies the bootstrapping and development of production-grade Java applications. Created by Pivotal (now VMware Tanzu) in 2014 by Phil Webb and Dave Syer, it has become the most popular Java application framework with over 75,000 stars. Key features: auto-configuration that automatically configures application components based on classpath dependencies, eliminating manual XML configuration. Embedded web servers (Tomcat, Jetty, Undertow) allowing applications to run as standalone JAR files without external server deployment. Starter dependencies (spring-boot-starter-web, spring-boot-starter-data-jpa, etc.) providing opinionated dependency bundles for common use cases. Actuator module for production-ready features including health checks, metrics (Micrometer integration), environment info, and monitoring endpoints. Externalized configuration via application.properties, application.yml, environment variables, and command-line arguments with hierarchical override. DevTools for development-time features including automatic restart on code changes, LiveReload, and remote debugging. Banner customization and application event system. Profile support for environment-specific configurations (dev, test, prod). Batch processing via integration with Spring Batch. Security integration with Spring Security for authentication, authorization, and OAuth2. Data access via integration with Spring Data JPA, MongoDB, Redis, Cassandra, and Elasticsearch. Messaging integration with Kafka, RabbitMQ, and Artemis. Testing support with TestRestTemplate, WebMvcTest, DataJpaTest, and MockMvc annotations. GraalVM Native Image support for compiling to standalone native binaries with instant startup and low memory. Build with Maven or Gradle. Widely used in enterprise Java for microservices, REST APIs, and cloud-native applications.