Cleanest way in Gradle to get the path to a jar file in the gradle dependency cache

Your code can be simplified a bit, for example project.configurations.compile.find { it.name.startsWith("solr-solrj-") }.

You can also create a dedicated configuration for an artifact, to keep it clean; and use asPath if the fact that it can potentially return several locations works well for your use case (happens if it resolves same jar in several locations):

configurations {
  solr
}

dependencies {
  solr 'org.apache.solr:solr-solrj:3.5.0'
}

task findSolrJars() {
  println configurations.solr.asPath
}

To avoid copy-paste, in case you as well need that jar in compile configuration, you may add this dedicated configuration into compile one, like:

dependencies {
  solr 'org.apache.solr:solr-solrj:3.5.0'
  compile configurations.solr.dependencies
}

I needed lombok.jar as a java build flag to gwt builds this worked great !

configurations { 
 lombok
}
dependencies {
  lombok 'org.projectlombok:lombok+'
} 
ext {
   lombok = configurations.lombok.asPath
}

compileGwt {
  jvmArgs "-javaagent:${lombok}=ECJ"
}

I was surprised that the resolution worked early enough in the configuraiton phase, but it does.