JVM

JVM Structure

JVM Architecture

Life of JVM

Loading

ClassLoader

public class ClassLoaderTest{
    public static void main(String[] args){
        // 系统类加载器
        ClassLoader systemClassLoader =  ClassLoader.getSystemClassLoader();
        System.out.println(systemClassLoader); //  
        //获取系统类加载器的上级：扩展类加载器
        ClassLoader extClassLoader = systemClassLoader.getParent();
        System.out.println(extClassLoader); // 

        // 获取本类的加载器
        ClassLoader selfClassLoader = ClassLoaderTest.class.getClassLoader();
        System.out.println(selfClassLoader);  // 
    }
}

双亲委派机制

What makes it all the same:

PC register

VM Stack

操作数栈（表达式栈）

动态链接

Native Method Interface

Native Method Stack

Default Garbage Collector : G1