Install

  1. Download latest release of Jetbrains Runtime 17, unpack it and set JAVA_HOME to it’s location (or add it as JDK to your IDE).
  2. Download latest release of Hotswap agent jar, unpack hotswap-agent.jar and copy it to <JBR-install-directory>/lib/hotswap folder. When using the agent, it’s important to note that the file name in lib/hotswap folder should not contain the version name, and should instead use the plain hotswap-agent.jar filename.

Configure

  1. Run your application with JBR using additional options: -XX:+AllowEnhancedClassRedefinition -XX:HotswapAgent=fatjar
  2. (optional) create a file named “hotswap-agent.properties” inside your resources directory, see available properties and default values: https://github.com/HotswapProjects/HotswapAgent/blob/master/hotswap-agent-core/src/main/resources/hotswap-agent.properties
  3. (optional) in case you are not using autoHotswap=true and therefore not using the hotswapping mechanism provided by HotswapAgent, you may want to add -Xlog:redefine+class*=info as an additional JVM argument in order to get feedback about reloaded classes.

Run

  1. start the application in debug mode, check that the agent and plugins are initialized correctly:

     HOTSWAP AGENT: 9:49:29.548 INFO (org.hotswap.agent.HotswapAgent) - Loading Hotswap agent - unlimited runtime class redefinition.
 HOTSWAP AGENT: 9:49:29.725 INFO (org.hotswap.agent.config.PluginRegistry) - Discovered plugins: [org.hotswap.agent.plugin.hotswapper.HotswapperPlugin, org.hotswap.agent.plugin.jvm.AnonymousClassPatchPlugin, org.hotswap.agent.plugin.hibernate.HibernatePlugin, org.hotswap.agent.plugin.spring.SpringPlugin, org.hotswap.agent.plugin.jetty.JettyPlugin, org.hotswap.agent.plugin.tomcat.TomcatPlugin, org.hotswap.agent.plugin.zk.ZkPlugin, org.hotswap.agent.plugin.logback.LogbackPlugin]
 ...
 HOTSWAP AGENT: 9:49:38.700 INFO (org.hotswap.agent.plugin.spring.SpringPlugin) - Spring plugin initialized - Spring core version '3.2.3.RELEASE'

  2. save a changed resource and/or use the HotSwap feature of your IDE to reload changes