Bootstrap Class Loader

• What it is:
  • A special built-in loader written in native code (part of the JVM).
  • Responsible for loading core Java classes.
• What it loads:
  • java.lang.*, java.util.*, and other standard library classes from the JDK.
  • These classes are found in the JAVA_HOME/lib directory (or modules in modern JDK).
• When it’s used:
  • Always runs first at JVM startup.
  • Ensures the runtime environment has access to essential classes.

👉 Example:

Class<?> c = Object.class;  // Loaded by Bootstrap Class Loader 
System.out.println(c.getClassLoader());  // prints: null (Bootstrap loader is represented as null)