How to `whitelist-package` with Payara Micro Bundle?

Question

According to this blog article, in order to use Google Guava with Payara, it needs to be "whitelisted", however, how to whitelist-package with Payara Micro Bundle?

The application web.xml does not accept <whitelist-package>com.google</whitelist-package>

Answer 1

You only need to whitelist the Google Guava library if you want to use the version that is already bundled in Payara Server. If you'd rather want to use Google Guava library that is present in your application WAR, you can do one of the following:

• disable classloading delegation (always load any classes from your app, only loads classes from Payara server if they don't exist in your app)
• enable the whitelisting mechanism and include only packages that should be loaded from Payara Server, e.g. org.glassfish (don't include Guava). All the other packages would be loaded from the application

If you whitelist com.google like in your example, Payara Server won't search for that package and subpackages in your application and only attempt to load the classes from Payara Server. This is I think the opposite of what you want.

For more info about classloading in Payara Server (including classloading delegation and whitelisting), see the docs at https://docs.payara.fish/community/docs/5.2020.4/documentation/payara-server/classloading.html.