Java important topics list for interviews

These are some of the important concepts you need to be very clear with , when you attend any interviews for bigger companys. Try to understand each of these concepts with some real world examples. 

Basic Concepts:
  • Class vs Interface vs Abstract class. 
  • Static variables.
  • final variables.
  • Access modifiers - Public, Private, Default, Protected. 
  • Immutable Strings and String manipulation concepts.
  • Object lifecycle - How objects are created and destroyed.

Threads:
  • Thread Dump analysis
  • Producer Consumer problem
  • Dead lock problem
  • Synchronisation
  • Thread creation lifecycle
  • Priority
  • Sleep
  • IsAlive
  • Join

Core:
  • JVM Internals
  • ClassLoaders
  • Reflections
  • Periodic task threads
  • GC threads
  • Compiler threads
  • Signal dispatcher thread

Design Patterns:
  • Singleton
  • Adapter
  • Lazy loading
  • Builder vs fluent 
  • Observer Patterns

Heap Management:
  • Young Generation
  • Old Generation (also called Tenured Generation)
  • Permanent Generation
  • JIT: Native code compilation



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