Java CompletableFuture Patterns for Async Code
Master CompletableFuture composition patterns including chaining, combining, error handling, timeouts, and async pipeline design in Java.
·6 min read · #java#completablefuture#async
#java
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Pattern Matching with Switch Expressions in Java
Master Java pattern matching in switch expressions. Covers type patterns, guarded patterns, sealed class exhaustiveness, and record deconstruction patterns.
·6 min read · #java#pattern-matching#switch
Java Records and Sealed Classes for Domain Modeling
Use Java Records and Sealed Classes to build expressive domain models. Covers compact constructors, sealed hierarchies, pattern matching, and real-world examples.
·6 min read · #java#records#domain-modeling
Java Records and Sealed Classes Explained
Master Java records for immutable data and sealed classes for controlled type hierarchies with pattern matching and practical domain modeling.
·7 min read · #java#records#sealed-classes
Spring Boot Security with JWT Authentication
Implement JWT authentication in Spring Boot 3. Covers security filter chain, token generation, refresh tokens, role-based access, and common security pitfalls.
·5 min read · #java#spring-boot#security
Advanced Java Stream API Patterns
Go beyond basic filtering and mapping with advanced Stream API patterns including custom collectors, parallel streams, and stateful operations.
·7 min read · #java#streams#functional
Advanced Stream Collectors and Custom Collectors in Java
Go beyond basic Java Stream collectors. Learn groupingBy compositions, teeing, custom Collector implementations, and performance considerations.
·5 min read · #java#streams#collectors
A Practical Guide to Java Virtual Threads
Master Java virtual threads with hands-on examples. Learn thread creation, executor patterns, structured concurrency, pinning pitfalls, and migration strategies.
·6 min read · #java#concurrency#virtual-threads
Java Optional: Avoiding NullPointerException
Learn how to use Java Optional to write null-safe code. Covers creation, chaining with map and flatMap, best practices, and common anti-patterns to avoid.
·6 min read · #java#optional#intermediate
Pattern Matching in Java
Master Java pattern matching with instanceof, switch expressions, record patterns, and guarded patterns for cleaner, more expressive conditional logic.
·8 min read · #java#patterns#intermediate
Java Streams API: A Complete Guide
Master Java Streams for functional-style data processing. Covers stream creation, map, filter, reduce, collectors, parallel streams, and performance considerations.
·7 min read · #java#streams#intermediate
Java Concurrency with CompletableFuture
How CompletableFuture composes asynchronous work in Java: chaining, combining, error handling, executors, and the patterns that keep concurrent code readable.
·4 min read · #java#concurrency#completablefuture
Java Exception Handling Best Practices
Clear rules for using checked and unchecked exceptions in Java, with patterns for wrapping, logging, and propagating errors in real production code.
·4 min read · #java#exceptions#error-handling
Java Generics: Wildcards and Bounds
Understand Java generics deeply: type parameters, upper and lower bounds, the PECS rule, and why type erasure shapes the rules you have to follow.
·4 min read · #java#generics#wildcards
Java Lambda Expressions Tutorial
Learn how Java lambda expressions work, when to use them, and how they interact with functional interfaces and the Streams API.
·3 min read · #java#lambda#functional
JUnit 5 Tutorial: Writing Clean, Modern Java Tests
A complete introduction to JUnit 5. Learn the new architecture, lifecycle, parameterized tests, assertions, and patterns that keep your test suite fast and readable.
·4 min read · #java#junit#testing
Java JPA vs Hibernate Comparison
Understand the difference between JPA the specification and Hibernate the implementation, and when each abstraction matters in practice.
·3 min read · #java#jpa#hibernate
Java JDBC Tutorial
Connect to relational databases from Java using JDBC: drivers, PreparedStatement, transactions, connection pooling, and resource management.
·3 min read · #java#jdbc#sql
Maven vs Gradle: Choosing a Build Tool for Java Projects
An honest comparison of Maven and Gradle. Understand their philosophies, performance, ecosystem, and how to choose the right build tool for your Java project.
·4 min read · #java#maven#gradle
Mockito Tutorial: Mocking Dependencies in Java Tests
Learn how to use Mockito to write fast, focused unit tests. Understand mocks, stubs, spies, argument captors, and how to avoid over-mocking.
·4 min read · #java#mockito#testing
Java Multithreading and Synchronization: A Practical Guide
Understand threads, the Java memory model, synchronization, locks, and concurrent collections. A practical guide to writing correct multithreaded Java code.
·4 min read · #java#concurrency#multithreading
Java Optional Best Practices
Use Java's Optional type correctly: when to return it, when to avoid it, and how to chain operations safely without ever calling get().
·3 min read · #java#optional#null-safety
Java Records vs Lombok
Records and Lombok both reduce boilerplate, but they solve overlapping problems in very different ways. Here is when to pick which, with concrete tradeoffs.
·5 min read · #java#records#lombok
Spring Data JPA Tutorial: Repositories, Queries, and Transactions
Learn Spring Data JPA from the ground up. Understand repositories, derived queries, JPQL, pagination, and transaction boundaries in real Java apps.
·4 min read · #java#spring#jpa
Spring Security Basics: Authentication, Authorization, and Filters
A practical introduction to Spring Security. Understand the filter chain, configure authentication, set up authorization rules, and avoid common mistakes.
·4 min read · #java#spring#security
Java Stream Collectors Deep Dive
Master java.util.stream.Collectors with practical examples covering grouping, partitioning, downstream collectors, and building your own custom collector.
·4 min read · #java#streams#collectors
Java Streams API Deep Dive
A practical tour of the Java Streams API: how it works, when to use it, lazy evaluation, collectors, parallel streams, and the pitfalls that trip up newcomers.
·4 min read · #java#streams#functional
Spring Boot Dependency Injection Explained
How Spring Boot wires your beans: component scanning, constructor injection, qualifiers, profiles, and the testing strategies that follow from each choice.
·4 min read · #java#spring#spring-boot
Spring MVC vs Spring WebFlux
Compare Spring's two web stacks: thread-per-request Spring MVC versus reactive non-blocking WebFlux, and how to choose between them.
·3 min read · #java#spring#webflux
Java Classes and Objects: OOP From Scratch
Design Java classes that hold state and behavior cleanly. Constructors, encapsulation, static vs instance, records, and the equals plus hashCode contract.
·5 min read · #java#oop#beginner
Java Collections Framework: List, Set, Map
Pick the right Java collection by performance and semantics. ArrayList vs LinkedList, HashMap vs TreeMap, immutability, and iteration without surprises.
·5 min read · #java#collections#intermediate
Java Control Flow: if, for, while, switch
Every branching and looping construct in modern Java, including switch expressions and pattern matching, with examples that mirror real code.
·5 min read · #java#control-flow#beginner
Java Inheritance and Polymorphism
Use extends, super, and method overriding without painting yourself into a corner. When to inherit, when to compose, and how sealed types help.
·5 min read · #java#oop#intermediate
Install Java and Write Your First Program
Install a modern JDK, verify the toolchain, and ship your first Java program from the command line without an IDE doing the magic for you.
·4 min read · #java#setup#beginner
Java Interfaces vs Abstract Classes
Choose between interfaces and abstract classes with confidence. Default methods, sealed interfaces, functional interfaces, and concrete decision rules.
·5 min read · #java#oop#intermediate
Java Streams and Lambdas: Functional Style on the JVM
Transform collections with lambdas and the Stream API. Map, filter, reduce, collectors, parallel streams, and the pitfalls of lazy pipelines.
·5 min read · #java#streams#intermediate
Java Variables and Primitive Types
Master Java primitives, reference types, literals, and casting. Know exactly what each type costs and where overflow and precision will bite you.
·5 min read · #java#types#beginner