Rate Limiting with Spring Boot and Bucket4j

The "Surgical" Security Struggle The "Upgrade Treadmill" in Enterprise Java: Why a BOM isn't always the answer. We’ve all been there. A high-severity CVE drops for a low-level library like Tomcat or Spring Core. The security scanners go red. The mandate is clear: Fix it now. In a perfect world, you just bump your Spring Boot BOM version, and you're done. But in a complex microservices architecture, it’s rarely that simple. 🛑 The Problem with the "All-in" Upgrade: Upgrading an entire BOM to patch a single vulnerability often feels like using a sledgehammer to crack a nut. A full version jump can introduce breaking changes, regression risks, and a massive testing overhead that the current sprint simply can’t absorb. 🔪 The "Surgical" Patch Reality: To stay compliant without breaking the build, we often resort to surgical overrides—pinning specific versions in <properties> or using <dependencyManagement>. It solves the immediate security risk, but it comes with a hidden cost: Dependency Drift: You end up with a "Franken-build" that deviates from the framework’s tested path. Maintenance Debt: Those "temporary" overrides become ghosts in your POM files, eventually blocking future upgrades or causing version conflicts months later Architectural Fatigue: Managing dozens of individual exclusions across a microservices landscape is an exhausting treadmill. The Middle Ground? As architects, we have to stop treating these as "interruptions" and start treating Dependency Freshness as a core system health metric. Whether it’s using a centralized Parent POM to manage overrides or leveraging the Maven Enforcer Plugin to prevent version chaos, the goal is the same: Stay secure, but stay sane. How is your team handling the constant stream of Java/Spring CVEs? Are you a "Bump the BOM" purist, or are you living the "Surgical Override" life? #Java #SpringBoot #Microservices #CyberSecurity #SoftwareArchitecture #DevSecOps #TechLead

"SELECT * FROM users WHERE email = '" + userInput + "'" This single line has destroyed more applications than most developers realize. SQL Injection is not dead. It is still one of the most exploited web vulnerabilities because developers assume: “Framework handle kar lega.” Spring Boot helps — but unsafe native queries, manual JDBC, dynamic filters, and careless repository methods can still leave your application open. Recently even modern Spring ecosystem vulnerabilities reminded teams that input sanitization mistakes are still very real. I created a deep practical guide for developers with: ✔ attack examples ✔ vulnerable code demos ✔ prevention implementation ✔ testing strategies ✔ production-ready secure coding checklist Useful for every Java/Spring Boot engineer. Read the full article 👇 https://lnkd.in/gCtWkSrC #SpringBoot #JavaDeveloper #ApplicationSecurity #SQLInjection #Coding #Programming #TechBlog #Developers

I've been going through Spring Security in Action - 2nd Edition for some time now. It's been a solid read for getting into the fundamentals of how the framework works under the hood. Application security has become a critical area especially today, where systems are heavily exposed through APIs and AI-driven applications are becoming more common. The book covers key concepts that play a major role in building secure applications. #Java #SpringBoot #SpringSecurity #ApplicationSecurity

FilenameUtils.getName() looks like a safe choice. It strips path components and returns just the filename. Without canonical path validation against a base directory though, you've solved one problem and left another wide open. Part 2 of the directory traversal series on Security Depth digs into what actually holds up in production: Apache Commons IO done right, frontend designs that never expose server paths, rate limiting and audit logging for active exploitation attempts, comprehensive unit tests for path validation, and SAST integration to keep regressions out of main. 🔗 https://lnkd.in/disppiww #AppSec #DirectoryTraversal #JavaSecurity #SpringBoot #OWASP #SecureCoding #ApplicationSecurity

🚨 5 Spring Boot Mistakes That Are Silently Killing Your App 🚨 After reviewing hundreds of Spring Boot codebases, these are the mistakes I see over and over again. Are you guilty of any? 👇 ----- ❌ Mistake #1 — Hardcoding Your Configuration Putting DB passwords, API keys, or URLs directly in `application.properties` or worse, in your code? That’s a security disaster waiting to happen. ✅ Use environment variables, `@ConfigurationProperties`, or Spring Cloud Config / HashiCorp Vault. Keep secrets OUT of your repo. ----- ❌ Mistake #2 — Trusting @Transactional Blindly Did you know calling a `@Transactional` method from WITHIN the same class silently bypasses the transaction? Spring uses proxies — self-invocation skips them entirely. ✅ Always call `@Transactional` methods from OUTSIDE the bean. And test it. Always. ----- ❌ Mistake #3 — Ignoring N+1 Query Problems Using `FetchType.EAGER` everywhere or not auditing your JPA queries = your app hammers the DB with hundreds of unnecessary queries under load. ✅ Use `@EntityGraph`, JOIN FETCH in JPQL, or lightweight DTOs/projections. Only fetch what you actually need. ----- ❌ Mistake #4 — Field Injection with @Autowired Field injection looks clean but it’s a trap: → Can’t easily write unit tests → Hides real dependencies → Causes NullPointerExceptions in unexpected places ✅ Use constructor injection. It’s explicit, testable, and immutable. Your future self will thank you. ----- ❌ Mistake #5 — No Global Exception Handling Letting raw stack traces reach your API consumers is unprofessional and a security risk. ✅ Use `@ControllerAdvice` + `@ExceptionHandler` to return clean, structured, consistent error responses across your entire application. ----- 💡 Spring Boot is incredibly powerful — but only if you use it right. Which of these have you encountered in the wild? Drop a comment below! 👇 ♻️ Repost if this helped someone on your team! #SpringBoot #Java #BackendDevelopment #SoftwareEngineering #CleanCode #SpringFramework #JavaDeveloper #Programming #TechTips #100DaysOfCode

🔍 Filters vs Interceptors in Spring Boot — and why most devs mix them up Both intercept HTTP requests. Both let you run logic before and after your controller. But they live at completely different layers — and choosing the wrong one leads to subtle bugs. Here's the mental model that clears it up: Filter = Servlet Container layer. Runs before DispatcherServlet even knows a request came in. It sees everything — including static resources. Interceptor = Spring MVC layer. Runs after DispatcherServlet, before your controller method. It knows which handler is being called. The one-line rule I use: If it needs to apply to every request, use a Filter. If it needs to know which endpoint is being called, use an Interceptor. This distinction matters for: → Security — JWT pre-checks live in Filters, role validation in Interceptors → Logging — request metadata at filter level, execution time at interceptor level → Clean architecture — putting logic at the right layer keeps things testable Swipe through the full breakdown with code examples and comparison table 👇 💬 Drop a comment: Which one do you use more in production, and for what? #SpringBoot #Java #BackendDevelopment #Microservices #SpringMVC #JavaDeveloper #SoftwareArchitecture #TechInterview #SpringFramework #Programming

🔐 Before implementing OAuth 2.0 in my bachelor's thesis project, I decided to deeply understand how Spring Security actually works under the hood. This diagram is the result of that research. Once you understand the filter chain, everything clicks: ✅ 1. DelegatingFilterProxy is just ONE filter among many in the Servlet container — it acts purely as a bridge, delegating to FilterChainProxy — the central entry point inside Spring Security, registered as a Spring bean named springSecurityFilterChain. ✅ 2. FilterChainProxy holds a list of SecurityFilterChain instances (injected during Spring context initialization) and selects the appropriate chain by evaluating each RequestMatcher against the incoming HTTP request — first match wins. ✅ 3. The selected SecurityFilterChain provides its own ordered list of filters, executed internally via VirtualFilterChain — completely isolated from the Servlet chain. 🤔 Why does this matter for OAuth 2.0? Because OAuth 2.0 login is implemented as a set of filters inside the selected SecurityFilterChain, including OAuth2AuthorizationRequestRedirectFilter and OAuth2LoginAuthenticationFilter, which together handle redirection to the provider, processing the callback request containing the authorization code, exchanging it for an access token, and creating the final Authentication object stored in the SecurityContext. Have you ever dug this deep into Spring Security? What do you think about this breakdown — did I miss anything or get something wrong? Drop a comment 👇 #SpringSecurity #SpringBoot #Java #OAuth2 #BackendDevelopment #BachelorThesis

You type a URL. JSON appears. But what actually happens in between? DNS → TCP → TLS → Load Balancer → Spring Boot → Hibernate → MySQL → JSON response. Every backend dev should understand this end-to-end flow. Which step was new to you? 👇 #api #backenddevelopment #webdevelopment #programming #softwareengineering

🚀 Day 8 of Building a Production-Ready Backend Where Most Security Implementations Fail I configured Spring Security today. And here’s the truth: 👉 Spring Security does NOTHING unless you configure it correctly. 💡 What I did: Defined public vs protected routes Configured Security Filter Chain 🧠 Key learning: Security is explicit, not implicit 🎯 Now the system knows: Which APIs are open Which require authentication #SpringSecurity #Java #BackendDevelopment #Security

🔐 𝗝𝗪𝗧 𝗔𝘂𝘁𝗵𝗲𝗻𝘁𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗶𝗻 𝗦𝗽𝗿𝗶𝗻𝗴 𝗦𝗲𝗰𝘂𝗿𝗶𝘁𝘆 In this guide, I break down the key components involved in implementing JWT-based authentication using Spring Security. You’ll learn how the pieces fit together and how to build a secure, stateless authentication flow. Here’s what is covered : 🔸 𝗔𝘂𝘁𝗵𝗲𝗻𝘁𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗙𝗶𝗹𝘁𝗲𝗿 : How incoming requests are intercepted and JWTs are validated. 🔸𝗧𝗵𝗲 𝗙𝗶𝗹𝘁𝗲𝗿 𝗖𝗵𝗮𝗶𝗻 : The order of security filters and why it matters for request processing. 🔸𝗔𝘂𝘁𝗵𝗲𝗻𝘁𝗶𝗰𝗮𝘁𝗶𝗼𝗻 𝗣𝗿𝗼𝘃𝗶𝗱𝗲𝗿 : How credentials or tokens are verified and users are authenticated. Whether you’re building a REST API or a modern microservice, understanding these parts is crucial for secure authentication. #SpringBoot #SpringSecurity #JWT #Authentication #RESTAPI #Java #Microservices #APISecurity #WebDevelopment #BackendDevelopment