What Is HotSpot?

JVM Tutorials - Herong's Tutorial Examples - Version 4.23, by Dr. Herong Yang

JVM Tutorials - Herong's Tutorial Examples

∟What Is HotSpot?

This section describes what is HotSpot - A Java VM (Virtual Machine) developed by Sun Microsystems.

What Is HotSpot? Java HotSpot VM is developed by Sun Microsystems. It has key feature called adaptive compiler that application code will be analyzed as it runs to detect performance bottlenecks, or "hot spots". The Java HotSpot VM will then compile those hot spots for a boost in performance.

There are two implementations of the Java HotSport VM:

Java HotSpot Client VM
Java HotSpot Server VM

The main differences of the two implementations are:

The Client VM has been specially tuned to reduce application start-up time and memory footprint, making it particularly well suited for client environments.
The Server VM has been specially tuned to maximize peak operating speed. It is intended for running long-running server applications, for which having the fastest possible operating speed is generally more important than having the fastest possible start-up time.

Both implementations of Java HotSpot VM are included inside the J2SDK installation package. The next two sections will explain how to invoke them.

By the way, Java HotSpot VM source code is available at http://openjdk.java.net/groups/hotspot/

Last update: 2014.

Table of Contents

About This Book

Downloading and Installing JDK 1.8.0 on Windows

Downloading and Installing JDK 1.7.0 on Windows

java.lang.Runtime Class - The JVM Instance

java.lang.System Class - The Operating System

ClassLoader Class - Class Loaders

Class Class - Class Reflections

►Sun's JVM - Java HotSpot VM