Explain how to install JBR manually

[peholmst]

in response to https://vaadin.com/forum/t/need-more-information-on-vscode-install-runtime-and-hotswap/178020/1

[github-actions]

AI Language Review

"Generic"

• Consistency in formatting: Ensure consistent use of formatting for notes, for example, sometimes notes are enclosed in [NOTE] and sometimes not.
• Check for consistent terminology: Ensure terms like "JetBrains Runtime" and "HotswapAgent" are consistently capitalized and referred to in the same manner throughout.
• Clarify the statement under "Enabling Hotswap Manually": It would be helpful to mention if there are specific IDE settings or prerequisites that need to be checked or adjusted before starting the described process.
• The term "hotswap" should be consistently hyphenated as "hot-swap" throughout the document.
• In "Example Command", clarify whether specific version numbers or additional options might need to be specified for -XX.

"Visual Studio Code"

• The "IMPORTANT" note about Copilot button availability references a link labeled <<../build#,production mode>> which may not render properly. Ensure this is correctly hyperlinked or explained.
• Ensure consistent terminology: in "Enabling Hotswap Using Vaadin Copilot," make sure "Copilot" is consistently capitalized when referring to the UI element.
• Clarify the use of "Development workflow": It would be useful to explain what "Development workflow" entails and why it is important in this context.

[MarcinVaadin]

Is this guide dedicated for Visual Studio Code or generic? If for VS Code then easiest option is to use Vaadin extension and it will do everything for user. If it is supposed to be generic tutorial, then we should remove VS Code references.

[peholmst]

That's a good question. The forum was referring to the VS Code page, but the instructions are indeed generic. The Vaadin extension instructions are already listed on the page (at the top). I'll try to move the instructions to its own page.

[manolo]

Creating a new launch configuration file for each application can be a bit cumbersome for regular Vaadin developers.

To streamline the debugging experience, we should mention in the docs, that Hotswap Agent can be enabled globally by adding the following lines to the global settings.json file (note that path should refer the specific home of the JBR installed, this is mine):

"java.home": "/Library/Java/JavaVirtualMachines/jbrsdk-21.0.5-osx-x64-b631.16/Contents/Home/",
"java.debug.settings.vmArgs": "-XX:HotswapAgent=fatjar -XX:+AllowEnhancedClassRedefinition -XX:+UpdateClasses"

For opening the global settings.json file in the IDE:

1. Open the Settings UI using Cmd+, (Mac) or Ctrl+, (Windows/Linux).
2. Click the icon in the top right corner saying “Open Settings (JSON)” when hovered.

This ensures the Hotswap Agent is always enabled when launching or debugging Java applications in VS Code, without needing per-project launch configuration files.

[manolo]

If for VS Code then easiest option is to use Vaadin extension and it will do everything for user

@MarcinVaadin it seems that user still needs to install JBR and set manually this runtime as main one in their IDE, or the extension does?

[peholmst]

I've been trying to create a generic instruction that only uses Maven and a text editor. As the classpath is huge, I've tried to use ./mvnw to start the application. I can see from the logs that hotswap agent is activated, but it does not detect when I recompile the project. Is this something that requires an IDE and special tool support?

[peholmst]

Answering my own question: I guess Maven does not do incremental builds.

[peholmst]

No, Maven seems to have some support for incremental builds. But HotswapAgent also needs to be notified that a class file has been changed. Need to check if there is any configuration flag for watching the file system.

[peholmst]

Found the missing pieces. I have now created a generic guide that shows you how you can run the app with hotswap using the command line only.

[MarcinVaadin]

@manolo

If for VS Code then easiest option is to use Vaadin extension and it will do everything for user

@MarcinVaadin it seems that user still needs to install JBR and set manually this runtime as main one in their IDE, or the extension does?

Extension does everything.