Java
Practical Java tutorials covering Javalin, collections, null safety, equality, memory management, and backend development.
All Java Guides
Deep dives, examples, and production tips
Javalin Tutorial: Build Fast Java REST APIs (Lightweight & Modern)
Master Javalin for Java 17/21+. Build lightweight REST APIs, handle JSON, path params, input validation, WebSockets, and async endpoints without Spring bloat.
Javalin File Upload: Simple Examples for Beginners
Master Javalin file uploads with step-by-step examples. Learn basic to advanced implementation techniques including file validation, error handling, and security best practices.
Javalin Servlets and Filters
Master Javalin Servlets and Filters with practical examples. Learn essential concepts through easy-to-follow code snippets perfect for Java beginners.
What is the Difference Between `==` and `equals()` in Java?
Learn the key differences between == and equals() in Java, including examples, best practices, and when to use each. Understand how to compare objects and primitives effectively.
HashMap vs Hashtable in Java
Learn the key differences between HashMap and Hashtable in Java, including synchronization, performance, and usage. Discover when to use each and explore modern alternatives like ConcurrentHashMap.
How to Avoid Checking for Nulls in Java
Learn how to avoid null checks in Java using Optional, the Null Object Pattern, annotations, and modern libraries. Discover best practices for writing cleaner, null-safe code.
Create, Detect, and Handle Memory Leaks in Java
Learn what is memory leak in Java, how to create, detect, and handle memory leaks in Java and Spring Boot. Includes examples, tools, and tips for fixing stack and byte array memory leaks.
Java NullPointerException, and How Do I Fix It?
Learn Java what a NullPointerException is, why it occurs, and how to fix and prevent it in your code. Explore practical solutions, best practices, and resources for handling null references effectively.