Spring Boot Validation Done Right | Custom Annotations Explained

Ready to move beyond basic validation in Spring Boot? In this step-by-step tutorial, we dive deep into creating your own custom validation rules to handle complex business logic that built-in annotations like @NotNull or @Size can't manage. This is Episode 2 of our Spring Validation series! If you're new, check out Episode 1 on predefined validation rules here: https://youtu.be/5ZfZwhW0nFo?si=X7JZ8uhuQpw0JLIY Sometimes your application needs more specific rules. What if a student's age must logically match their date of birth? What if a birth date needs to be at least 17 years in the past, not just any past date? That's where custom validation comes in, and in this video, we'll build two powerful custom validators from scratch to solve these exact problems. 👇 **What you will learn in this video:** - The limitations of standard validation annotations. - How to create your own custom validation annotation (e.g., @MinimumAge). - How to build the validator class with your business logic using `ConstraintValidator`. - How to apply custom validation at the **field level** (for a single property). - How to create and apply validation at the **class level** to compare multiple fields. - How to update your `CustomValidationException` handler to return clean error messages for both field and class-level errors. By the end of this guide, you'll be able to create bulletproof validation for any business requirement in your Spring Boot applications! 💬 **Questions or ideas?** Drop a comment below! What's the most complex validation rule you've ever had to write? #SpringBoot #Java #SpringFramework #Validation #CustomValidation #API #Backend #ProgrammingTutorial 🔗 BONUS 💻 Get 3 Months of IntelliJ IDEA Ultimate for FREE: https://www.jetbrains.com/store/redeem/ 👉 *Use Promo Code:* LearnWithIfte ✅ For branding and Business inquiries ► learnwithiftekhar@gmail.com ► Join Discord: https://discord.gg/JZmFvSxw 🎯🎯 *Subscribe to my Newsletter:* https://learnwithiftekhar.substack.com/ 📘 Resources Mentioned: 🧑‍💻 Source Code: https://github.com/learnwithiftekhar/spring-boot-data-validation 🙊 Here are the tools and resources I use in my videos: 👉 Master programming by recreating your favorite technologies: https://app.codecrafters.io/join?via=learnwithiftekhar ► Tool that I use for screen recording: CleanShot X for Mac * cleanshot.sjv.io/bODOab ⛔ Background sound: https://share.epidemicsound.com/ia954g 💻 *Running Windows on Mac? Get Parallels Desktop with a 20% discount!* 👉 *Use code PARALLELS20 and grab it here:* https://parallels.sjv.io/bOVD3M IDE I use for coding * IntelliJ Idea Ultimate * VsCode * Sublime 🌐 Secure your connection with NordVPN: https://nordvpn.sjv.io/o4zYan 🤚 In case you want to contact me: ❌ My LinkedIn profile: https://www.linkedin.com/in/hossain-md-iftekhar/ ❌ My X / Twitter profile: https://twitter.com/ifte_hsn ❌ Github: Github: https://github.com/learnwithiftekhar *Note:* Some of the links in this description are affiliate links, and I may earn a small commission if you make a purchase through them. Thank you for your support.