How to use Dynamic Code Evolution VM (DCEVM) in IntelliJ Java debugger

Question

Dynamic Code Evolution VM seems to be obsolete. Can it be used in IntelliJ IDEA?

Answer

DCEVM can still be used with IntelliJ IDEA and JBR 17/21.

You can follow this tutorial to get it configured in the IDE using the free and open-source HotSwapAgent plugin.

Note that every step is important:

• Proper JBR
• HotSwap agent jar
• +XX... VM option

Alternatively, check out the instructions in the plugin readme.

Note that you can simplify the setup process using the HotSwapHelper plugin.

Additional resources

• How to use HotSwap mechanism in IntelliJ IDEA to reload modified classes: https://www.jetbrains.com/help/idea/altering-the-program-s-execution-flow.html#reload_classes
• HotSwap limitations: https://www.jetbrains.com/help/idea/altering-the-program-s-execution-flow.html#hotswap-limitations
• Original blog post published by JetBrains on the subject: https://blog.jetbrains.com/idea/2013/07/get-true-hot-swap-in-java-with-dcevm-and-intellij-idea/
• HotSwapAgent public forum: https://groups.google.com/g/hotswapagent
• IntelliJ HotSwapHelper plugin: https://plugins.jetbrains.com/plugin/25171-hotswaphelper
• JetBrains Runtime public releases: https://github.com/JetBrains/JetBrainsRuntime/releases