Java (21) For Non-Beginner

Prerequisites

  • Solid understanding of Java basics (OOP, collections, exceptions)
  • Experience with build tools (Maven/Gradle)
  • Basic understanding of design patterns
  • Familiarity with testing concepts

Phase 1: Modern Java Features (3-4 weeks)

Pattern Matching

  • Type patterns
  • Record patterns
  • Switch expressions with patterns
  • Pattern matching for instanceof
  • Sealed classes and patterns
  • Exhaustiveness checking

Virtual Threads and Structured Concurrency

  • Understanding virtual threads vs platform threads
  • Structured concurrency
  • Thread scheduling and management
  • Migration strategies from traditional threading
  • Best practices and patterns
  • Performance implications

Records and Sealed Types

  • Record patterns and composition
  • Pattern matching with records
  • Sealed interfaces and classes
  • Permits clauses
  • Migration strategies
  • Design patterns with sealed types

Modern Language Features

  • Text blocks
  • Enhanced switch expressions
  • Helpful NullPointerExceptions
  • Foreign Function & Memory API
  • Vector API

Phase 2: Advanced Concurrency (4-5 weeks)

Concurrent Collections

  • ConcurrentHashMap internals
  • Queue implementations
  • BlockingQueue variations
  • CopyOnWriteArrayList
  • Custom concurrent collections

Synchronization Mechanisms

  • Locks and conditions
  • Semaphores
  • CountDownLatch
  • CyclicBarrier
  • Phaser
  • StampedLock

Executors and Thread Pools

  • ThreadPoolExecutor internals
  • Fork/Join framework
  • Work stealing
  • Custom thread pool implementations
  • Monitoring and tuning

Asynchronous Programming

  • CompletableFuture deep dive
  • Custom executors
  • Reactive programming concepts
  • Project Reactor basics
  • Integration patterns

Phase 3: Performance Optimization (4-5 weeks)

JVM Internals

  • Memory model
  • Garbage collection algorithms
  • JIT compilation
  • Class loading
  • Memory leaks detection
  • Performance profiling

Memory Management

  • Stack vs heap
  • Object layout
  • Escape analysis
  • Memory barriers
  • Off-heap memory
  • Direct ByteBuffer

Performance Tuning

  • JVM flags and tuning
  • Garbage collector tuning
  • Thread pool tuning
  • Connection pool optimization
  • Profiling tools mastery
  • Benchmarking techniques

Code Optimization

  • String pool and interning
  • Collection choice optimization
  • Algorithm optimization
  • Data structure selection
  • Cache-friendly code
  • Lock-free programming

Phase 4: Advanced Topics (4-5 weeks)

Reflection and Metaprogramming

  • Dynamic proxy
  • Annotation processing
  • Bytecode manipulation
  • Custom class loaders
  • Runtime code generation
  • Java agents

Security

  • Security manager
  • Cryptography
  • SSL/TLS handling
  • Secure coding practices
  • Security vulnerabilities
  • Access control

Testing and Quality

  • JUnit 5 advanced features
  • Property-based testing
  • Mutation testing
  • Performance testing
  • Load testing
  • Security testing

Integration and Monitoring

  • JMX deep dive
  • Custom metrics
  • Monitoring solutions
  • Logging best practices
  • Tracing solutions
  • APM integration

Phase 5: Project Implementation (3-4 weeks)

Project Ideas

  1. Custom thread pool with monitoring
  2. Lock-free data structure implementation
  3. High-performance cache system
  4. Custom classloader with security
  5. Reactive event processing system

Advanced Implementation Topics

  • Design patterns for concurrency
  • Performance optimization patterns
  • Security patterns
  • Testing patterns
  • Monitoring patterns

Practice and Assessment

Hands-on Exercises

  • Implementing concurrent data structures
  • Writing lock-free algorithms
  • Creating custom thread pools
  • Building monitoring solutions
  • Developing security features

Performance Challenges

  • Optimize existing applications
  • Solve concurrency puzzles
  • Debug memory leaks
  • Tune JVM parameters
  • Implement benchmarks

Project Milestones

  • Design and implement concurrent systems
  • Create high-performance solutions
  • Build secure applications
  • Develop monitoring solutions
  • Write comprehensive tests

Learning Resources

Documentation

  • JDK documentation
  • JEP specifications
  • Java Language Specification
  • Java Virtual Machine Specification

Books and Papers

  • Java Concurrency in Practice
  • Optimizing Java
  • The Well-Grounded Java Developer
  • Research papers on JVM internals

Tools

  • JMH (Java Microbenchmark Harness)
  • JFR (Java Flight Recorder)
  • JMC (Java Mission Control)
  • VisualVM
  • Async-profiler

Community Resources

  • OpenJDK mailing lists
  • Java Champions blogs
  • Conference talks
  • Research papers