Java Platform and Internal Architecture of Java Virtual Machine(J VM)

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 Java Platform

  • Java is a programming language and a platform.
  • A Platform is hardware or software environment in which a program runs. Most popular platforms like Microsoft Windows, Linux, Solaris OS, and Mac OS.
  • Java is a software-only platform that runs on top of other hardware-based platforms.
  • The Java platform has two components: 
  1.       The Java Virtual Machine(JVM)
  2.       The Java Application Programming Interface (API)
API is grouped into libraries of related classes and interfaces, these libraries are known as packages.



Java Virtual Machine(JVM)

JVM is the part of Java Run Time Environment(JRE) and it is responsible to load and run the java class file.



Internal Architecture of Java Virtual Machine(JVM)


Class Area : It stores per-class structures such as the run time constant pool, field and method data, the code for methods.

Heap : Run time data area in which objects are allocated.

Stack : Stores frames to hold local variables and partial results.

PC Register : Address of the Java virtual machine instruction currently being executed.

Native Method Stack : Native methods used in the application.

Execution Engine : Virtual processor, Interpreter, JIT compiler

Just-In-Time(JIT) compiler reads the bytecodes in many sections (or in full, rarely) and compiles them dynamically into machine language so the program can run faster.

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