[NIO] 디렉토리 모니터링 API(WatchService)

Watching Path

One of the nicest feature of the NIO File API is the WatchService, which can monitor a Path for change to any file or directory in the hierarchy.

 

import java.io.IOException; import java.nio.file.FileSystem; import java.nio.file.FileSystems; import java.nio.file.Path; import java.nio.file.StandardWatchEventKinds; import java.nio.file.WatchEvent; import java.nio.file.WatchKey; import java.nio.file.WatchService; import java.util.List;     /**  * @author Steven J.S Min  *  */ public class WatchingPaths {          /**         * @param args         * @throws IOException         */        public static void main(String[] args) throws IOException {                 FileSystem fs = FileSystems.getDefault();                 Path watchPath = fs.getPath("C:/Temp/1");               WatchService watchService = fs.newWatchService();               watchPath.register(watchService,                            StandardWatchEventKinds.ENTRY_CREATE,                            StandardWatchEventKinds.ENTRY_MODIFY,                            StandardWatchEventKinds.ENTRY_DELETE);                 while (true) {                      try {                                                       // 지정된 디렉토리에 변경이되는지 이벤트를 모니터링한다.                            WatchKey changeKey = watchService.take();                                                       List<WatchEvent<?>> watchEvents = changeKey.pollEvents();                              for (WatchEvent<?> watchEvent : watchEvents) {                                   // Ours are all Path type events:                                   WatchEvent<Path> pathEvent = (WatchEvent<Path>) watchEvent;                                     Path path = pathEvent.context();                                   WatchEvent.Kind<Path> eventKind = pathEvent.kind();                                     System.out.println(eventKind + " for path: " + path);                             }                              changeKey.reset(); // Important!                        } catch (InterruptedException e) {                            e.printStackTrace();                      }                 }        }   }