Why Spring Boot over plain Spring in Spring Boot - See It in Action

Why Spring Boot over plain Spring

📖 Scenario: You are a developer starting a new Java web project. You want to understand why using Spring Boot can make your work easier compared to using plain Spring Framework.

🎯 Goal: Learn the key differences and benefits of Spring Boot over plain Spring by creating a simple Spring Boot application setup step-by-step.

📋 What You'll Learn

Create a basic Spring Boot application class

Add a configuration property for server port

Use Spring Boot's auto-configuration feature

Add a simple REST controller to complete the app

💡 Why This Matters

🌍 Real World

Spring Boot is widely used to quickly build production-ready web applications and microservices with minimal setup.

💼 Career

Understanding Spring Boot is essential for Java developers working in enterprise environments, as it speeds up development and reduces boilerplate code.

1

Create the Spring Boot application class

Create a Java class called Application annotated with @SpringBootApplication and add a main method that runs SpringApplication.run(Application.class, args).

Spring Boot

// Your code here

Need a hint?

This class is the entry point of your Spring Boot app. The @SpringBootApplication annotation enables auto-configuration.

2

Add a configuration property for server port

Create a file called application.properties in src/main/resources and set the property server.port=8081 to configure the server port.

Spring Boot

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

# Create application.properties file with server.port=8081

Need a hint?

This property changes the default server port from 8080 to 8081, showing how easy configuration is with Spring Boot.

3

Use Spring Boot's auto-configuration feature

Explain in a comment how @SpringBootApplication enables auto-configuration, so you don't need to write XML or manual setup for common features like embedded server and component scanning.

Spring Boot

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

# application.properties
server.port=8081

// Your explanation here

Need a hint?

Auto-configuration saves time and reduces errors by setting up defaults for you.

4

Add a simple REST controller to complete the app

Create a class called HelloController annotated with @RestController. Add a method hello() annotated with @GetMapping("/hello") that returns the string "Hello, Spring Boot!".

Spring Boot

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.GetMapping;

@SpringBootApplication // Enables auto-configuration, component scanning, and configuration
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

# application.properties
server.port=8081

// The @SpringBootApplication annotation tells Spring Boot to automatically configure the app,
// so you don't have to write XML or manual setup for common tasks like starting the server or scanning components.

// Your code here

Need a hint?

This controller shows how easy it is to create REST endpoints with Spring Boot.