gradle checkstyle error:Expected file collection to contain exactly one file, however, it contains 14 files - gradle

Question

I am using Java 8 with Gradle and trying to add the Google checkstyle rules into the build, but what I get is this error:
"Expected file collection to contain exactly one file, however, it contains 14 files."
My configuration is:
apply plugin: 'checkstyle'
configurations {
checkstyleConfig
}
def versions = [
checkstyle: '8.8',
]
dependencies {
checkstyleConfig "com.puppycrawl.tools:checkstyle:${versions.checkstyle}"
}
checkstyle {
toolVersion = "${versions.checkstyle}"
config = resources.text.fromArchiveEntry(configurations.checkstyleConfig, 'google_checks.xml')
}

Answer 1

The issue here is that configurations.checkstyleConfig includes multiple JAR files: com.puppycrawl.tools:checkstyle, as well as all of its transitive dependencies. Debugging the issue locally, I see that these dependencies are being included:
antlr:antlr:2.7.7
com.google.code.findbugs:jsr305:1.3.9
com.google.errorprone:error_prone_annotations:2.1.3
com.google.guava:guava:23.6-jre
com.google.j2objc:j2objc-annotations:1.1
com.puppycrawl.tools:checkstyle:8.8
commons-beanutils:commons-beanutils:1.9.3
commons-cli:commons-cli:1.4
commons-collections:commons-collections:3.2.2
commons-logging:commons-logging:1.2
net.sf.saxon:Saxon-HE:9.8.0-7
org.antlr:antlr4-runtime:4.7.1
org.checkerframework:checker-compat-qual:2.0.0
org.codehaus.mojo:animal-sniffer-annotations:1.14
The fix for this is fortunately very simple. All you need to do is exclude the transitive dependencies from the Checkstyle dependency, and the rest of your script will work the way you want it to:
dependencies {
checkstyleConfig("com.puppycrawl.tools:checkstyle:${versions.checkstyle}") { transitive = false }
}

Answer 2

btw, for future reference, there's no need to add a new configuration to use this, it's just a matter of filtering the checkstyle dependency from the existing configuration used by the plgin.
This is the config I use:
checkstyle {
config = resources.text.fromArchiveEntry(
configurations.checkstyle.find { it.name.contains('checkstyle') },
'google_checks.xml'
)
}

Answer 3

For anyone interested, this is the Kotlin DSL variant of the config from #thiago answer:
checkstyle {
config = resources.text.fromArchiveEntry(
configurations.checkstyle.get().find { it.name.contains("checkstyle") }!!,
"google_checks.xml"
)
}