How to mix ResolutionStrategies with Gradle - gradle

Question

Let's say I have the following in my gradle build script:
configurations.all {
resolutionStrategy {
failOnVersionConflict()
force 'com.google.guava:guava:18.0'
}
}
This will fail if more than one version of a jar is found, except for guava where it will force to version 18.0.
Now let's imagine that I want to have failOnVersionConflict() for all external jars, and be forced to use the force clause (so I know what I'm doing), but I want to use the default resolutionStrategy (newest version) for some specific group, like com.mycompany.
Is such a thing possible?
I was looking at this documentation page:
https://gradle.org/docs/current/dsl/org.gradle.api.artifacts.ResolutionStrategy.html

Answer 1

I found my own answer... But it involves a bit of "hacking"... But, after all, that's just what gradle offers...
def dependencyErrors = 0
configurations.all {
resolutionStrategy {
def thirdPartyPackages = [:]
def forced = [
'com.google.guava:guava' : '18.0'
//Here all forced dependencies...
]
eachDependency { DependencyResolveDetails details ->
if (!details.requested.group.startsWith('com.mycompany')) {
def key = details.requested.group + ":" + details.requested.name
if(!thirdPartyPackages.containsKey(key)) {
if(forced.containsKey(key)) {
details.useVersion forced.get(key)
}
else {
thirdPartyPackages.put(key, details.requested.version);
}
}
else {
def existing = thirdPartyPackages.get(key);
if(existing != details.requested.version) {
logger.error "Conflicting versions for [$key]"
logger.error " [$existing]"
logger.error " [$details.requested.version]"
dependencyErrors++
}
}
}
}
}
}
myTask.doFirst {
//here it might also be doLast, or whatever you need. I just put it before a war task, but it might depend on each need.
if(dependencyErrors > 0) {
ant.fail 'There are ' + dependencyErrors + ' conflicting jar versions in the build.'
}
}