Support springboot buildpack immutable images

When building an image from buildpack (mvn spring-boot:build-image), this is executed over the unzipped jar (launching main class directly) but the current approach is only considering the execution over the fat-jar (java -jar .....jar).

InJarArtifactResolver (when the jar is unpacked and run in an exploded form) finds resourceURL but it's a simple directory, not a jar as expected:

resourceURL "file:/workspace/" (buildpack)

vs.

resourceURL "jar:file:/home/gmunozfe/git/quartz-cluster-springboot-kie-server/target/quartz-cluster-springboot-kie-server-1.0.0.jar!/BOOT-INF/classes!/" (local)

Same with autoScan scenario:

appHome.getSource()

is a directory, so it throws this exception:

Factory method 'buildAutoScanDeployments' threw exception; nested exception is java.io.FileNotFoundException: /workspace/BOOT-INF/classes (Is a directory)

 

Reproducer project: https://github.com/gmunozfe/quartz-cluster-springboot-kie-server