Java FileSystem.newWatchService()
Syntax
FileSystem.newWatchService() has the following syntax.
public abstract WatchService newWatchService() throws IOException
Example
In the following code shows how to use FileSystem.newWatchService() method.
/*from w w w.j a v a2 s. co m*/
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
public class Main {
public static void main(String[] args) throws Exception {
FileSystem fileSystem = FileSystems.getDefault();
WatchService watchService = fileSystem.newWatchService();
Path directory = Paths.get("c:/");
WatchEvent.Kind<?>[] events = { StandardWatchEventKinds.ENTRY_CREATE,
StandardWatchEventKinds.ENTRY_DELETE,
StandardWatchEventKinds.ENTRY_MODIFY };
directory.register(watchService, events);
while (true) {
System.out.println("Waiting for a watch event");
WatchKey watchKey = watchService.take();
System.out.println("Path being watched: " + watchKey.watchable());
System.out.println();
if (watchKey.isValid()) {
for (WatchEvent<?> event : watchKey.pollEvents()) {
System.out.println("Kind: " + event.kind());
System.out.println("Context: " + event.context());
System.out.println("Count: " + event.count());
System.out.println();
}
boolean valid = watchKey.reset();
if (!valid) {
// The watchKey is not longer registered
}
}
}
}
}
The code above generates the following result.
