Java Software Engineering
From write-once-run-anywhere to modern cloud-native OpenJDK enterprise development.
Master the world's most battle-tested enterprise programming language. Learn the JVM bytecode engine, object-oriented design, the OpenJDK ecosystem, memory models, and modern high-performance Java patterns.
Course Overview
Welcome to Java Software Engineering on codeworking.org. Java is the language of global banking, massive distributed cloud backends, high-throughput financial transactions, and Android applications.
What You Will Master
- The OpenJDK Ecosystem: Understanding the open-source distributions (Eclipse Temurin, Microsoft JDK, Amazon Corretto).
- JVM Execution Engine: How Java source code compiles to portable bytecode and is JIT-compiled into native CPU machine instructions.
- Object-Oriented Engineering: Mastering the 4 pillars (Encapsulation, Abstraction, Inheritance, Polymorphism) for clean architecture.
- Enterprise Design Patterns: Writing resilient, scalable, and memory-safe enterprise backend services.
Prerequisites
- Basic familiarity with general computer usage. No prior Java experience necessary.
Structured Learning Roadmap
Java Foundations, Ecosystem & Core Language Mechanics
History of Java, the OpenJDK ecosystem, JVM architecture, primitive types, memory models, and control flow.
What is Java & The OpenJDK Revolution
Explore the origins of Java from Sun Microsystems in 1995 to the Oracle acquisition and the modern, open-source OpenJDK ecosystem powering enterprise software.
Why Java & Object-Oriented Programming
Understand why Java remains the dominant language for enterprise backends and cloud systems. Master the JVM bytecode engine and the four core principles of OOP.
Primitive Types, Stack/Heap Memory Models & Value Semantics
Master Java's 8 primitive types, Two's Complement storage, Stack vs Heap memory allocation, reference wrapper overhead, and strict pass-by-value mechanics.
Control Flow, Pattern Matching & The Modern Switch
PlannedBranching, loops, type patterns in switch expressions, exhaustiveness, and null handling.
Object-Oriented Engineering & Modern Type Systems
Encapsulation, inheritance, polymorphism, sealed hierarchies, records, and interfaces.
Classes, Encapsulation & The Object Lifecycle
PlannedConstructors, instance variables, 'this', factory methods, and heap allocation.
Inheritance, Polymorphism & Virtual Method Dispatch
PlannedV-tables in the JVM, dynamic method lookup, method overriding vs overloading, and super.
Interfaces, Default Methods & Multiple Interface Inheritance
PlannedAPI contracts, default/static interface methods, conflict resolution, and loose coupling.
Records, Sealed Classes & Modern Algebraic Data Types
PlannedImmutable data carriers, canonical constructors, sealed class permits, and pattern matching.
Advanced Data Structures, Collections & Generics
ArrayList vs LinkedList, HashMap treeification, TreeMap, and Generic type erasure.
Lists, Deques & Iterators: ArrayList vs LinkedList
PlannedContiguous array memory layout, 1.5x geometric resizing, ArrayDeque, and fail-fast iterators.
Hash Tables, Treeification & The HashMap Architecture
PlannedBucket arrays, hash spread functions, and Red-Black treeification after 8 collisions.
Tree-Based Collections: TreeMap, TreeSet & Red-Black Trees
PlannedNavigableMap range queries, O(log n) guarantees, Comparable vs Comparator strategies.
Java Generics, Type Erasure & PECS Principles
PlannedGeneric classes, bytecode bridge methods, and Producer-Extends Consumer-Super (PECS).
Functional Programming, Streams API & Modern Java Features
Lambdas, Functional interfaces, Streams pipelines, Optionals, and Virtual Threads (Project Loom).
Lambda Expressions, Method References & Functional Interfaces
PlannedSAM interfaces, invokedynamic instruction, Function/Predicate/Consumer, and lexical scoping.
The Streams API: Lazy Evaluation, Map-Filter-Reduce & Collectors
PlannedIntermediate vs terminal operations, custom collectors, Spliterators, and parallel streams.
Null-Safety, Optional Pattern & Exception Architecture
PlannedChecked vs unchecked exceptions, Optional anti-patterns, and modern monadic chaining.
Virtual Threads (Project Loom) & Structured Concurrency
PlannedPlatform threads vs 1-million Virtual Threads, Carrier threads, and non-blocking I/O.
JVM Deep Dive, Memory Architecture & Concurrency
ClassLoader delegation, JIT compilation, G1/ZGC garbage collectors, and JFR diagnostics.
ClassLoader Hierarchy, Bytecode & The .class File
PlannedBootstrap/Platform/App classloaders, bytecode opcodes, and javap disassembly.
The JIT Compiler: C1, C2 Tiered Compilation & Escape Analysis
PlannedInterpreter profiling, HotSpot method compilation, loop unrolling, and scalar replacement.
Garbage Collection Architecture: G1 GC & ZGC Mechanics
PlannedWeak generational hypothesis, Eden/Survivor/Tenured generations, and sub-millisecond ZGC.
Java Flight Recorder (JFR), Profiling & Memory Leak Diagnosis
PlannedLow-overhead continuous profiling, heap dump histograms, and thread contention diagnosis.
Enterprise Architecture, Spring Ecosystem & Cloud-Native Java
NIO.2 zero-copy, Spring Boot 3, Hibernate N+1 solutions, and GraalVM native images.
High-Performance I/O, NIO.2 & Zero-Copy Architecture
PlannedByteBuffer channels, kernel sendfile zero-copy, and asynchronous socket channels.
Spring Boot 3, Dependency Injection & Dynamic AOP Proxies
PlannedIoC containers, bean lifecycles, and JDK Dynamic Proxies vs CGLIB bytecode generation.
JPA / Hibernate, N+1 Query Resolution & HikariCP Pooling
PlannedEntity state lifecycle, JOIN FETCH solutions, L2 caching, and connection pool optimization.
GraalVM Native Images, AOT Compilation & Microservices
PlannedAhead-of-Time (AOT) native compilation, instant startup, and tiny memory containerization.