Why Spring Boot over plain Spring in Spring Boot

Introduction

Spring Boot makes building applications faster and easier by handling setup and configuration for you. Plain Spring requires more manual setup and can be slower to start.

When you want to quickly create a web application without writing lots of setup code.

When you prefer automatic configuration to avoid manual XML or Java config.

When you want to use embedded servers like Tomcat without extra setup.

When you want to easily package your app as a standalone executable jar.

When you want to use ready-made starter dependencies to add features quickly.

Syntax

Spring Boot

No special syntax difference in code, but Spring Boot uses @SpringBootApplication annotation to start apps easily.

@SpringBootApplication combines @Configuration, @EnableAutoConfiguration, and @ComponentScan.

Spring Boot uses opinionated defaults to reduce configuration.

Examples

This is a minimal Spring Boot app starter with automatic configuration.

Spring Boot

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

Plain Spring requires manual annotations and setup for web apps.

Spring Boot

@Configuration
@EnableWebMvc
@ComponentScan
public class MyConfig {
  // manual Spring setup
}

Sample Program

This Spring Boot app starts quickly with embedded server and serves a simple web page at root URL.

Spring Boot

package com.example.demo;

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

@SpringBootApplication
public class DemoApplication {

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

  @RestController
  static class HelloController {
    @GetMapping("/")
    public String hello() {
      return "Hello from Spring Boot!";
    }
  }
}

Important Notes

Spring Boot reduces boilerplate and speeds up development.

You can still use plain Spring if you want full control, but it takes more setup.

Spring Boot starters help add features like web, data, security easily.

Summary

Spring Boot automates setup and configuration for faster app building.

It uses embedded servers and starter dependencies for convenience.

Plain Spring requires more manual configuration and setup.