Introduction to Spring Security 6
Explore the fundamental concepts and architecture of Spring Security 6, understanding its role in securing web applications.
Introduction to Spring Security 6 is a free Spring Security 6 & JWT Authentication lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Spring Security 6 & JWT Authentication learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Welcome to Spring Security!
Time to lock down your Java apps. Spring Security 6 is the framework that handles authentication and access control so you don't roll your own.
What is Spring Security?
Spring Security is a customizable auth and access-control framework for Spring Boot apps. Authentication proves who you are; authorization decides what you can touch.
Why Security Matters
Unprotected apps invite unauthorized access, data breaches, and DoS. Spring Security gives you a battle-tested layer to shut those doors.
AuthN vs. AuthZ: Key Terms
Two terms, often confused: Authentication proves who you are (username + password), while authorization decides what you're allowed to do. Spring handles both.
Spring Security's Core Approach
Under the hood, Spring Security runs as a chain of servlet filters. Every request passes through them, each one handling one job: auth, authz, sessions.
The Security Filter Chain
The FilterChainProxy intercepts each HTTP request and runs it through an ordered series of security filters before it ever hits your controllers.
Understanding the SecurityContext
Once authenticated, a user's identity and roles live in the SecurityContext, managed by SecurityContextHolder. That's how Spring knows who's logged in.
Default Spring Boot Security
Just add spring-boot-starter-security and Boot locks down every endpoint with a generated login page — security on by default, no config needed.
Default Security in Action
Add Spring Security to a minimal Boot app and hit the root URL — it redirects you straight to a generated login page. The code below shows the setup.
package com.coddykit;
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
@RestController
public class SecurityIntroApplication {
public static void main(String[] args) {
SpringApplication.run(SecurityIntroApplication.class, args);
}
@GetMapping("/")
public String home() {
return "Welcome to a secured application!";
}
}Check Your Understanding
Let's test your grasp of the core concepts we've covered.
Recap: Spring Security Basics
Recap: Spring Security guards Java apps, separates authentication from authorization, and runs every request through a filter chain — protected out of the box with Boot.
Frequently asked questions
Is the “Introduction to Spring Security 6” lesson free?
Yes — the full text of “Introduction to Spring Security 6” is free to read here on the web, and the Spring Security 6 & JWT Authentication course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Spring Security 6 & JWT Authentication course, upgrade to CoddyKit PRO.
What will I learn in “Introduction to Spring Security 6”?
Explore the fundamental concepts and architecture of Spring Security 6, understanding its role in securing web applications. You practise Spring Security 6 & JWT Authentication with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Spring Security 6 & JWT Authentication?
No prior experience is required. Spring Security 6 & JWT Authentication on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Introduction to Spring Security 6” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Spring Security 6 & JWT Authentication lesson?
Yes. Every Spring Security 6 & JWT Authentication lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Introduction to Spring Security 6
- Project Setup and Dependencies
- In-Memory User Authentication
- Understanding the Spring Security Filter Chain