Java NIO2 watch service example

simple-watching-service.groovy

import java.nio.file.FileSystems
import java.nio.file.Path
import java.nio.file.Paths
import java.nio.file.StandardWatchEventKinds
import java.nio.file.WatchKey
import java.nio.file.WatchService

import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE
import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE
import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY

def watchService = FileSystems.getDefault().newWatchService()

def path = Paths.get(System.getProperty('user.home'), "/watching")

println path

path.register(watchService, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY)
WatchKey key
while ((key = watchService.take()) != null) {
  key.pollEvents().each { event ->
    println "event ${event.kind()} on '${event.context()}'"
  }
  key.reset()
}

watchService.close()