Depending on ASM itself can cause problems as it can clash with other
libraries' dependency on it. This commit updates
spring-boot-loader-tools to depend upon spring-core and use its
repackaged copy of ASM instead. Depending on spring-core also brings
with it the advantage of giving access to its various bits of utility
code.
spring-boot-maven-plugin has been updated to remove its ASM
exclusions as they will no longer clash with the version from
spring-boot-loader-tools
(59483608)
Prior to this commit, the Aether-based GrapeEngine was loaded in the
same class loader as the rest of Boot. This led to Aether's and its
dependencies' types polluting the application's class path. Most
notably, this caused problems with logging as the logging framework
could be permaturely initialized.
This commit isolates AetherGrapeEngine, Aether and its dependencies
into a separate class loader. This is done by customizing the
packaging of the CLI's jar file with the internal directory housing
all of the types that will be loaded by the separate class loader.
Andy Wilkinson
Dave Syer
Phillip Webb