Recently, I ran into an issue with a colleague trying to upgrade some old jsp-based projects to use spring boot and run them in containers. This repo provides examples of how to get a jsp application using spring-boot and running an embedded tomcat servlet container to be packaged and run as a jar.
It contains two Eclipse projects.
- spring-boot-jsp-war show-cases the usual way of doing it. The application runs with an embedded tomcat container and a war packaging. It can be run in a server/container like so:
java -jar spring-boot-jsp-war.war - spring-boot-jsp-jar show-cases how to do the same thing with jar packaging. This is not straight-forward due to certain limitations with jsps
If for whatever reason, you can't deal with a war packaging, there's a bit of a hack you can try. Full credit to this guy here for doing this for the older versions of spring boot.
One way to do this is to personalize tomcat and add BOOT-INF/classes to tomcat's ResourceSet. In tomcat, all scanned resources are put into something called a ResourceSet. For example, the META-INF/resources of the application jar package in the servlet 3.0 specification is scanned and put into the ResourceSet.
Now we need to find a way to add the BOOT-INF/classes directory of the fat jar to the ResourceSet. We can do this through the tomcat LifecycleListener interface, in the Lifecycle.CONFIGURE_START_EVENT event, get the BOOT-INF/classes URL, and then add this URL to the WebResourceSet.