内置 Classloader Bootstrap Class Loader Java classes are loaded by an instance of java.lang.ClassLoader. However, class loaders are classes themselves. Hence, the question is, who loads the java.lang.ClassLoader itself*?* This is where the bootstrap or primordial class loader comes into the picture. It’s mainly responsible for loading JDK internal classes, typically rt.jar and other core libraries located in $JAVA_HOME/jre/lib directory. Additionally, Bootstrap class loader serves as a parent of