When an application is run as an executable archive with nested jars,
the application's own classes need to be able to load classes from
within the nested jars. This means that the application's classes need
to be loaded by the same class loader as is used for the nested jars.
When an application is launched with java -jar the contents of the
jar are on the class path of the app class loader, which is the
parent of the LaunchedURLClassLoader that is used to load classes
from within the nested jars. If the root of the jar includes the
application's classes, they would be loaded by the app class loader
and, therefore, would not be able to load classes from within the
nested jars.
Previously, this problem was resolved by LaunchedURLClassLoader being
created with a copy of all of the app class laoder's URLs and by
using an unconventional delegation model that caused it to skip its
parent (the app class loader) and jump straight to its root class
loader. This ensured that the LaunchedURLClassLoader would load both
the application's own classes and those from within any nested jars.
Unfortunately, this unusual delegation model has proved to be
problematic. We have seen and worked around some problems with Java
Agents (see gh-4911 and gh-863), but there are others (see gh-4868)
that cannot be made to work with the current delegation model.
This commit reworks LaunchedURLClassLoader to use a conventional
delegate model with the app class loader as its parent. With this
change in place, the application's own classes need to be hidden
from the app class loader via some other means. This is now achieved
by packaging application classes in BOOT-INF/classes (and, for
symmetry, nested jars are now packaged in BOOT-INF/lib). Both the
JarLauncher and the PropertiesLauncher (which supports the executable
jar layout) have been updated to look for classes and nested jars in
these new locations.
Closes gh-4897
Fixes gh-4868
Generalize the `skip` property to start and stop goals so that one
can control if the Spring Boot app is starting via a configuration
property.
Note that this only controls the Spring Boot Maven plugin and the
failsafe maven plugin should be updated accordingly.
Closes gh-4922
Ensure that Collections.isEmpty() is used to check if there are no
elements in a collections. This is more explicit and can be faster than
calling .size().
Closes gh-4783
Replace all new-line characters in multi-line pom descriptions before
inserting into the launcher script. Prior to this commit the shell would
attempt to execut the extra lines, for example:
<description>
A multi-line pom description that could do something terrible:
rm -r foo
</description>
Closes gh-4703
Update the "INIT INFO section" of `launch.script` to include
`initInfoProvides`, `initInfoShortDescription` and `initInfoDescription`
property substitutions.
The Maven plugin has been updated to populate substitutions with
`${project.artifactId}`, `${project.name}` and `${project.description}`.
Fixes gh-4245
Flip the default value of `addResources` for both the Maven and Gradle
plugins. This effectively turns off static resources reloading and, more
importantly, the pruning of duplicate resources from the target
directory.
As devetools is our mainstram solution for such feature, the documantion
has been updated to reflect that.
Closes gh-4227
This commit adds a dedicated property to specify the active profiles to
use when running an application via the Maven plugin. This works also
on the command line using the `run.profiles` system property and is
consistently applied whether the process is forked or not.
Closes gh-4199
Add an `excludeDevtools` property to both the Maven and Gradle plugin
that removes `org.springframework.boot:spring-boot-devtools` (if
necessary) when repackaging the application.
Closes gh-3171
DevTools look for a main thread named "main". The maven plugin is
actually using a different value and there is no real reason to. This
change fixes DevTools support as long as forking is enabled.
See gh-3315
Previously, if the repackaged file was different from the main artifact
of the build, the maven plugin wrongly considered that it should attach
the file with a classifier.
The outputDirectory is honored properly now, regardless of the fact a
classifier is defined or not.
Fixes gh-3177
Andy Wilkinson
Phillip Webb
Stephane Nicoll
Spring Buildmaster
Kirill Vlasov
Robert Thornton
Johnny Lim
Dave Syer
Daniel Young and Mathew Johnson