Is the JVM a compiler or an interpreter?

First, let's have a clear idea of the following terms
Javac is Java Compiler -- Compiles your Java code into Bytecode
JVM is Java Virtual Machine -- Runs/ Interprets/ translates Bytecode into Native Machine Code
JIT is Just In Time Compiler -- Compiles the given bytecode instruction sequence to machine code at run-time before executing it natively. It's main purpose is to do heavy optimizations in performance.
So now, Let's find answers to your questions..
1)JVM: is it a compiler or an interpreter? -- Ans: Interpreter
2)what about JIT compiler that exist inside the JVM? -- Ans: If you read this reply completely, you probably know it now
3)what exactly is the JVM? -- Ans:
  • JVM is a virtual platform that resides on your RAM
  • Its component, Class loader loads the .class file into the RAM
  • The Byte code Verifier component in JVM checks if there are any access restriction violations in your code. (This is one of the principle reasons why java is secure)
  • Next, the Execution Engine component converts the Bytecode into executable machine code

Comments

Post a Comment

Popular posts from this blog

Spring Security ACL

Image
ACL Spring Security tutorial By Andrei Tudose and Ovidiu Gheorghies In this article we show how to implement a simple yet meaningful Spring Security based web application using PostgreSQL as a database backend. The learning curve for effective Spring Security usage was pretty steep for us, and we now write the article we wish we would have had in front of our eyes from the very beginning. As die-hard fans of PostgreSQL for its ease of use, scalability and extensibility, we faced a few perks now and then, but having learned how to deal with them, we are now happy to share. Most web applications use security to separate those who have to right to perform an action from those who don’t. In its simplest form, this may mean that registered users may post messages, unregistered users may only read them, while administrators can exercise their free will into editing, deleting, banning or generally annoying people. For more complex and realistic applications, one cannot si
Read more