? Java Class Loader

? Quick Overview

The Class Loader in Java is a part of the Java Runtime Environment (JRE) that dynamically loads Java classes into memory when they are required. It allows Java programs to run without knowing all classes at compile time.

? Key Concepts

• Loads .class files into JVM memory
• Follows a parent delegation model
• Prevents duplicate class loading
• Provides security and isolation

? Syntax / Theory

Java uses three main built-in class loaders:

• Bootstrap Class Loader – Loads core Java classes
• Extension Class Loader – Loads extension libraries
• Application Class Loader – Loads user-defined classes

? Code Example

// Demonstrating different Java Class Loaders
public class ClassLoaderDemo {

public static void main(String[] args) {

// Application Class Loader
ClassLoader appLoader = ClassLoaderDemo.class.getClassLoader();
System.out.println(appLoader);

// Extension Class Loader
System.out.println(appLoader.getParent());

// Bootstrap Class Loader (returns null)
System.out.println(appLoader.getParent().getParent());
}
}

? Live Output / Explanation