void generateChecksums(def files, def destination) {
   println files.getClass().name
   def checksums = [
         [suffix: 'md5', checksum: MessageDigest.getInstance("MD5")],
         [suffix: 'sha1', checksum: MessageDigest.getInstance("SHA-1")]
   ]
   def generateChecksums = {
      file ->
      def writeChecksum = {
         def checksumDigest = it.checksum.digest()
         def checksumFile = new File(destination, "${file.name}.$it.suffix")
         checksumFile.withPrintWriter { it.printf("${'%02x' * checksumDigest.size()} $file.name\n", checksumDigest) }
      }

      checksums.checksum*.reset()
      checksums.checksum*.update(file.getBytes())
      checksums.each writeChecksum
   }

   switch (files) {
      case { File.isCase(it) && it.file }:
         generateChecksums files
         break;

      case { File.isCase(it) && it.directory }:
         files.eachFileRecurse FILES, generateChecksums
         break;

      case TaskOutputs:
         generateChecksums files.files, destination
         break;

      default:
         files.each { generateChecksums it, destination }
         break;
   }
}

   task dist(dependsOn: 'ear', type: Copy) {
      def destination = ...
      from ear
      into destination
      doLast {
         generateChecksums ear.outputs, destination
      }
   }

private void generateChecksumsWrapper(def files, def destination) {
   generateChecksums(files, destination)
}

test('x');
def test(def x, def y) {
   println x
   if (x.length() < 6) {
      test("$x$x", y)
   }
}
test('x', 'y')