J
322 chapters
Learn Java
A complete Java tutorial — from your first Hello World on the JVM through object-oriented programming, the collections framework, streams, concurrency, modules, JDBC, and modern features like records, virtual threads, and pattern matching.
Getting started
Java Syntax & Basics
Control flow
Arrays
Methods
Object-Oriented Programming
- OOP concepts
- Classes & objects
- Class attributes
- Class methods
- Constructors
- this keyword
- Access modifiers
- Non-access modifiers
- static
- final
- Encapsulation
- Getters & setters
- Inheritance
- super keyword
- Polymorphism
- Method overriding
- Abstraction
- Abstract classes
- Interfaces
- Default methods
- Nested classes
- Inner classes
- Anonymous classes
- Local classes
- Enums
- Records
- Sealed classes
- instanceof
- Object class
- equals & hashCode
- toString
- Cloning
- Immutable classes
- Singleton pattern
Packages & Imports
Exception Handling
Strings In Depth
Generics
Collections Framework
- Collections intro
- Collection interface
- List interface
- ArrayList
- LinkedList
- Vector
- Stack
- Queue interface
- PriorityQueue
- ArrayDeque
- Deque interface
- Set interface
- HashSet
- LinkedHashSet
- TreeSet
- Map interface
- HashMap
- LinkedHashMap
- TreeMap
- Hashtable
- Properties
- Iterators
- ListIterator
- Comparable & Comparator
- Collections class
- Sorting collections
- Searching collections
- Unmodifiable collections
Functional Programming
File and I/O
Date and Time
Multithreading and Concurrency
- Multithreading intro
- Thread class
- Runnable
- Thread lifecycle
- Thread methods
- Thread priority
- Synchronization
- Synchronized blocks
- Inter-thread comms
- Deadlock
- volatile
- Atomic variables
- Locks
- ReentrantLock
- ReadWriteLock
- Thread pools
- Executor framework
- Callable & Future
- CompletableFuture
- Fork/Join
- Concurrent collections
- Virtual threads