The Java Virtual Machine (JVM) is the core component of Java that enables platform independence. It converts compiled Java bytecode into machine-specific instructions and manages memory, security, and execution.
? Key Concepts
Class Loader Loads .class files into memory
Runtime Data Areas Memory areas used during execution
Execution Engine Executes bytecode
JNI Connects Java with native libraries
Garbage Collector Automatic memory cleanup
? Interactive JVM Simulation
Click "Execute" to visualize how JVM handles the code.
Class Loader
Test.class
Stack Memory
main() Frame
arg: args[]
Heap Memory
String Object
"JVM Arch..."
Ready to start...
? Syntax / Theory
JVM works in multiple stages: class loading, linking, initialization, execution, and memory cleanup. Each Java program runs inside the JVM environment.
Method Area – Stores class metadata
Heap – Stores objects
Stack – Stores method calls and local variables
PC Register – Tracks current instruction
Native Method Stack – Executes native code
? Code Example(s)
? View Code Example
// Simple Java program executed by JVM
class JVMTest {
public static void main(String[] args) {
System.out.println("JVM Architecture Example");
}
}
? Live Output / Explanation
Output
JVM Architecture Example
The JVM loads the class, allocates memory in the heap, pushes main() to stack, and executes bytecode line by line.
✅ Tips & Best Practices
Understand memory areas to avoid memory leaks
Use proper object lifecycle management
Prefer JVM tuning only when necessary
Know how garbage collection works
? Try It Yourself
Run a Java program with -Xmx and -Xms options
Observe memory usage using JConsole
Modify code to create multiple objects and analyze heap behavior