Install

Use OpenJDK Hotswap instead of standard JDK-11. Download latest release of trava-jdk-11-dcevm, unpack it and set JAVA_HOME to it’s location (or add it as JDK to your IDE).

Configure

  1. Everything is configured for you, just run your application with downloaded JDK :-)
  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