Java WatchService.close()
Syntax
WatchService.close() has the following syntax.
void close() throws IOException
Example
In the following code shows how to use WatchService.close() method.
/*from w ww . j a v a 2 s.c o m*/
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchEvent.Kind;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.TimeUnit;
class SecurityWatch {
WatchService watchService;
private void register(Path path, Kind<Path> kind) throws IOException {
path.register(watchService, kind);
}
public void watchVideoCamera(Path path) throws IOException, InterruptedException {
watchService = FileSystems.getDefault().newWatchService();
register(path, StandardWatchEventKinds.ENTRY_CREATE);
OUTERMOST:
while (true) {
final WatchKey key = watchService.poll(11, TimeUnit.SECONDS);
if (key == null) {
System.out.println("The video camera is jammed - security watch system is canceled!");
break;
} else {
for (WatchEvent<?> watchEvent : key.pollEvents()) {
final Kind<?> kind = watchEvent.kind();
if (kind == StandardWatchEventKinds.OVERFLOW) {
continue;
}
if (kind == StandardWatchEventKinds.ENTRY_CREATE) {
//get the filename for the event
final WatchEvent<Path> watchEventPath = (WatchEvent<Path>) watchEvent;
final Path filename = watchEventPath.context();
final Path child = path.resolve(filename);
if (Files.probeContentType(child).equals("image/jpeg")) {
//print it out the video capture time
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
System.out.println("Video capture successfully at: " + dateFormat.format(new Date()));
} else {
System.out.println("The video camera capture format failed! This could be a virus!");
break OUTERMOST;
}
}
}
boolean valid = key.reset();
if (!valid) {
break;
}
}
}
watchService.close();
}
}
public class Main {
public static void main(String[] args) {
final Path path = Paths.get("C:/security");
SecurityWatch watch = new SecurityWatch();
try {
watch.watchVideoCamera(path);
} catch (IOException | InterruptedException ex) {
System.err.println(ex);
}
}
}