JRebel

JRebel is a JVM Java Agent that integrates with application servers, making classes reloadable with existing class loaders. Only changed classes are recompiled and instantly reloaded in the running application. JRebel plugs into IDEs and build systems. Classes and static resources are loaded straight from the workspace. JRebel integrates with over 100 frameworks. Dedicated JRebel plugins will rebuild caches, rewire components and apply configuration to the runtime as necessary.

Key Features:

• Compile in the IDE: With JRebel you avoid having to rebuild the entire application to reload code changes, this is a huge time savings. Instead of running your full build process, simply use the compiler built into your IDE and JRebel will reload the code into the JVM.
• Maven and Gradle: JRebel also supports reloading code inside of modules and build artifacts, as long as you have the source code. Classes and resources are read directly from your workspace, stop rebuilding your JARs, EARs and WARs to see code changes.
• Remote and virtual server support: With JRebel you can develop on virtual machines, remote servers and cloud environments as fast and easily as you do locally. JRebel sends the changed classes and resources to the remote server, reloading them instantly. This avoids the need to repackage your application, transfer it to the remote server and then go through the entire restart/redeploy process on the remote server.