Running a Spring Boot Application

Spring Boot provides multiple ways to run an application, making it suitable for development, testing, and production environments. You can run a Spring Boot app directly from an IDE, using build tools like Maven or Gradle, or as an executable JAR file.

1. Run from IDE (IntelliJ / Eclipse / STS)

This is the most common approach during development.

Steps:

Open the main class annotated with @SpringBootApplication
Right-click → Run
Spring Boot automatically:
- Starts the embedded server (Tomcat by default)
- Loads configuration
- Initializes the application

Why use this?

Fast feedback during development
Easy debugging and log visibility
No command-line setup required

2. Run Using Maven

You can run the application using Maven from the terminal:

mvn spring-boot:run

What happens internally:

Maven compiles the source code
Resolves and downloads dependencies
Executes the Spring Boot main class

Best suited for:

Local development
CI/CD pipelines
Maven-based projects

3. Run Using Gradle

For Gradle-based projects, use:

gradle bootRun

or (recommended):

./gradlew bootRun

Best suited for:

Gradle projects
Automated build and deployment setups

4. Run as an Executable JAR (Production-Style)

This is the most common production approach.

Step 1: Build the JAR

mvn clean package

Step 2: Run the JAR

java -jar myapp.jar

Why this is important:

No external application server required
Ideal for Docker, Kubernetes, and cloud platforms
Fully self-contained application

5. Run with a Specific Profile

Spring profiles allow environment-specific configuration.

java -jar myapp.jar --spring.profiles.active=dev

Common use cases:

Different databases for dev/test/prod
Different logging levels
Secure production settings

Spring Boot Application – Run Flow

Developer Action
      │
      ▼
Choose Run Method
      │
      ├── Run from IDE
      │       │
      │       └── @SpringBootApplication
      │               ↓
      │         Embedded Server Starts
      │               ↓
      │           Application Running
      │
      ├── Maven (mvn spring-boot:run)
      │       │
      │       └── Compile + Dependencies
      │               ↓
      │         Spring Boot Startup
      │               ↓
      │           Application Running
      │
      ├── Gradle (bootRun)
      │       │
      │       └── Gradle Build Lifecycle
      │               ↓
      │         Spring Boot Startup
      │               ↓
      │           Application Running
      │
      └── Executable JAR (java -jar)
              │
              └── JVM Starts
                      ↓
                Embedded Server
                      ↓
                Application Running

Conclusion

Spring Boot makes application execution simple, flexible, and production-ready.

Whether you run it from an IDE for development, use Maven or Gradle for automation, or deploy it as an executable JAR in production, Spring Boot handles everything with minimal configuration. Profile support ensures clean separation between environments, making Spring Boot ideal for modern and scalable applications.