Add a `NestedFileSystemProvider` implementation so that the JDK's
`ZipFileSystem` can load content from nested jars and nested
directory entries.
Creating a `ZipFileSystem` may be a relatively expensive operation as
zip structures need to be parsed and in the case of directory entries
a virtual datablock nees to be generated on the fly. As such, we
install the `ZipFileSystem` as late as possible since in a typical
application it may never be needed.
This commit also tweaks Gradle and Maven plugins to ensure that the
service loader file is written to repackaged jars.
Closes gh-7161
Update Gradle and Maven plugins to write an empty `META-INF/BOOT.SF`
file whenever there is a nested signed jar.
This update allows Oracle Java 17 to correctly verify the nested JARs.
The file is required because `JarVerifier` has code roughly equivalent
to:
if (!jarManifestNameChecked && SharedSecrets
.getJavaUtilZipFileAccess().getManifestName(jf, true) == null) {
throw new JarException("The JCE Provider " + jarURL.toString() +
" is not signed.");
}
The `SharedSecrets.getJavaUtilZipFileAccess().getManifestName(jf, true)`
call ends up in `ZipFile.getManifestName(onlyIfSignatureRelatedFiles)`
which is a private method that we cannot override in our `NestedJarFile`
subclass. By writing an empty `.SF` file we ensure that the `Manifest`
is always returned because there are always "signature related files".
Fixes gh-28837
Rewrite nested jar code to better align with the implementations
provided in Java 17. This update makes two fundamental changes to
the previous implementation:
- Resource cleanup is now handled using the `java.lang.ref.Cleaner`
- Jar URLs now use the form `jar:nested:/my.jar/!nested.jar!/entry`
Unlike the previous `jar🫙/my,jar!/nested.jar!/entry` URL format,
the new format is compatible with Java's default Jar URL handler.
Specifically, it now only uses a single `jar:` prefix and it no longer
includes multiple `!/` separators.
In addition to the changes above, many of the ancillary classes have
also been refactored and updated to create cleaner APIs.
Closes gh-37668
Create alternative launcher classes under the package
`org.springframework.boot.loader.launch` and use them in favor
of the previous location.
This update is designed to improve compatibility with future
changes in the loader.
Closes gh-37667
