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Java Programming

Core Java concepts and advanced topics.

Core Java Concepts

Object-Oriented Programming in Java

  • Classes and Objects

    • Strong encapsulation with access modifiers
    • Instance vs static members
    • Constructor overloading and chaining
    • Immutable class design

  • Inheritance and Polymorphism

    • Abstract classes vs interfaces
    • Default and static interface methods (Java 8+)
    • Method overriding rules
    • Covariant return types

  • Generics

    • Type parameters and wildcards
    • Generic methods and classes
    • Type erasure implications
    • PECS principle (Producer Extends Consumer Super)

Memory Management

  • JVM Memory Model

    • Heap vs Stack memory
    • Garbage collection mechanisms
    • Memory leaks and prevention
    • PermGen vs Metaspace

  • Reference Types

    • Strong references
    • Soft references
    • Weak references
    • Phantom references

Exception Handling

  • Exception Hierarchy
    • Checked vs unchecked exceptions
    • Custom exception design
    • Try-with-resources
    • Multi-catch blocks

Collections Framework

  • Core Interfaces

    • List, Set, Queue, Map implementations
    • Thread-safe collections
    • Performance characteristics
    • Custom collection implementations

  • Streams API

    • Stream operations (map, filter, reduce)
    • Parallel streams
    • Custom collectors
    • Optional class usage

Concurrency

  • Threading Fundamentals

    • Thread lifecycle
    • Synchronization mechanisms
    • Volatile keyword
    • ThreadLocal usage

  • Concurrent Utilities

    • ExecutorService framework
    • Fork/Join framework
    • CompletableFuture
    • Atomic classes
    • Concurrent collections

Java Language Features

  • Functional Programming

    • Lambda expressions
    • Method references
    • Functional interfaces
    • Stream API integration

  • Modern Java Features

    • Records (Java 16+)
    • Sealed classes (Java 17+)
    • Pattern matching
    • Text blocks
    • Switch expressions

Best Practices

  • Code Organization

    • Package structure
    • Dependency management
    • Module system (Java 9+)
    • API design principles

  • Performance Optimization

    • JVM tuning
    • Profiling techniques
    • Common bottlenecks
    • Optimization strategies

  • Testing

    • Unit testing with JUnit
    • Mocking frameworks
    • Test-driven development
    • Integration testing

Advanced Topics

  • Reflection API

    • Dynamic class loading
    • Method invocation
    • Annotation processing
    • Proxy classes

  • I/O and NIO

    • File operations
    • Buffered I/O
    • Channel API
    • Memory-mapped files

  • Security

    • Security Manager
    • Cryptography basics
    • SSL/TLS handling
    • Access control

  • JVM Internals

    • Class loading
    • Bytecode manipulation
    • JIT compilation
    • Performance monitoring