☕Java

The Ecosystem (How Java Runs) 🥪

• JVM, JRE, JDK & the Compilation Process
• Java Virtual Machine (JVM)
  • Garbage collection (GC)
  • Java’s Memory Model
• Hello World - Java

Syntax and Data Fundamentals

• Variables & Types
  • Basic Data Concepts
  • Primitive vs Reference types
  • Wrapper class
  • Pass-by-value and Pass-by-Reference
  • String (Literal & Class)
  • == and .equals
• Control Flow & Logic
  • Short circuit evaluation
  • Switch statements in Java
• Input/Output
  • Scanner
  • Java File IO
  • Java Serialization (and persistence)

OOP

• Class structure
  • Classes & Instances
  • Class vs Instance variables
  • Local VS Class VS Instance variables
  • Class vs Instance methods
  • Constructor & this
  • Modifiers: Access modifiers (접근 제어자) / Non-Access modifiers (기타 제어자) / Final
• The 4 Pillars
  • Inheritance in java (incl. Composition)
  • Encapsulation (incl. Immutable Objects)
  • Polymorphism in java (method overloading/overriding)
  • Abstraction - Classes & Interfaces
• Design Principles (SOLID)
  • SRP(Single Responsibility Principle)
  • OCP (Open Closed Principle)
  • LSP (Liskov’s Substitution Principle)
  • ISP (Interface Segregation Principle)
  • DIP (Dependency Inversion Principle)
  • Notion 링크

Java Collection Framework(JCF)

Literally just a java version of data structures 🍟

• Java Collections Framework (JCF)
• Lists:
  • list (java)
  • ArrayList in Collections
  • Arrays in Java
• Utilities:
  • Java Comparators & Comparable
  • Math class

Concurrency & Async

• Basics
  • Threads
• Modern Concurrency
  • Virtual Thread (Java 21+)
  • java 비동기 (This likely covers Future / CompletableFuture / Async)

Functional Programming

Modern Java (Java 8+ style).

• Lambda
• Functional Interfaces & Descriptor
• Method Reference
• Stream in Java

Generics & Meta-Programming

• Generics
  • Java Generics
  • using generic
• Meta
  • Java Annotation
  • Java exception handling

Useful tips (Intellij)

• Java packaging

Sources

• 점프 투 자바