JRebel

JRebel: Java Bytecode Hotswap Tool

JRebel is a Java bytecode hotswap tool that allows developers to instantly see any code change made to apps without redeploying or restarting the JVM. It works by updating class files dynamically at runtime.

What is JRebel?

JRebel is a popular Java bytecode hotswap tool used to accelerate the development of Java applications. It allows developers to instantly see any code change made to apps without needing to redeploy or restart the JVM. This saves significant time compared to the default process of repackaging and redeploying an app every time a code change is made.

JRebel works by instrumenting class files and updating them dynamically at runtime whenever a change is detected. This enables it to reload code changes on-the-fly while the application is still running. The updated classes are reloaded transparently without affecting the application state or requiring any server restarts.

Key benefits of using JRebel include faster development turnaround times, improved developer productivity, immediate code change visibility, and avoidance of server restarts during the dev testing cycle. It supports reloading changes made to application code, configs, and even JSP/web pages.

JRebel plugs into popular Java IDEs like Eclipse, IntelliJ and NetBeans to enable building, testing and running apps directly within the IDE while retaining the ability to instantly view code changes. It is compatible with most application servers like Tomcat, JBoss, Jetty, WebLogic etc.

JRebel requires a paid license after an initial 30 day trial period. It is available as an on-premise installable software as well as native plugins for Cloud platforms like AWS, Google Cloud and Azure.

JRebel Features

Official Links