/** Check that a cancelled key will never be queued */
static void testCancel(Path dir) throws IOException {
System.out.println("-- Cancel --");
try (WatchService watcher = FileSystems.getDefault().newWatchService()) {
System.out.format("register %s for events\n", dir);
WatchKey myKey = dir.register(watcher, new WatchEvent.Kind<?>[] {ENTRY_CREATE});
checkKey(myKey, dir);
System.out.println("cancel key");
myKey.cancel();
// create a file in the directory
Path file = dir.resolve("mars");
System.out.format("create: %s\n", file);
Files.createFile(file);
// poll for keys - there will be none
System.out.println("poll...");
try {
WatchKey key = watcher.poll(3000, TimeUnit.MILLISECONDS);
if (key != null) throw new RuntimeException("key should not be queued");
} catch (InterruptedException x) {
throw new RuntimeException(x);
}
// done
Files.delete(file);
System.out.println("OKAY");
}
}
/** Check that deleting a registered directory causes the key to be cancelled and queued. */
static void testAutomaticCancel(Path dir) throws IOException {
System.out.println("-- Automatic Cancel --");
Path subdir = Files.createDirectory(dir.resolve("bar"));
try (WatchService watcher = FileSystems.getDefault().newWatchService()) {
System.out.format("register %s for events\n", subdir);
WatchKey myKey =
subdir.register(
watcher, new WatchEvent.Kind<?>[] {ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY});
System.out.format("delete: %s\n", subdir);
Files.delete(subdir);
takeExpectedKey(watcher, myKey);
System.out.println("reset key");
if (myKey.reset()) throw new RuntimeException("Key was not cancelled");
if (myKey.isValid()) throw new RuntimeException("Key is still valid");
System.out.println("OKAY");
}
}
/** Simple test of each of the standard events */
static void testEvents(Path dir) throws IOException {
System.out.println("-- Standard Events --");
FileSystem fs = FileSystems.getDefault();
Path name = fs.getPath("foo");
try (WatchService watcher = fs.newWatchService()) {
// --- ENTRY_CREATE ---
// register for event
System.out.format("register %s for ENTRY_CREATE\n", dir);
WatchKey myKey = dir.register(watcher, new WatchEvent.Kind<?>[] {ENTRY_CREATE});
checkKey(myKey, dir);
// create file
Path file = dir.resolve("foo");
System.out.format("create %s\n", file);
Files.createFile(file);
// remove key and check that we got the ENTRY_CREATE event
takeExpectedKey(watcher, myKey);
checkExpectedEvent(myKey.pollEvents(), StandardWatchEventKinds.ENTRY_CREATE, name);
System.out.println("reset key");
if (!myKey.reset()) throw new RuntimeException("key has been cancalled");
System.out.println("OKAY");
// --- ENTRY_DELETE ---
System.out.format("register %s for ENTRY_DELETE\n", dir);
WatchKey deleteKey = dir.register(watcher, new WatchEvent.Kind<?>[] {ENTRY_DELETE});
if (deleteKey != myKey) throw new RuntimeException("register did not return existing key");
checkKey(deleteKey, dir);
System.out.format("delete %s\n", file);
Files.delete(file);
takeExpectedKey(watcher, myKey);
checkExpectedEvent(myKey.pollEvents(), StandardWatchEventKinds.ENTRY_DELETE, name);
System.out.println("reset key");
if (!myKey.reset()) throw new RuntimeException("key has been cancalled");
System.out.println("OKAY");
// create the file for the next test
Files.createFile(file);
// --- ENTRY_MODIFY ---
System.out.format("register %s for ENTRY_MODIFY\n", dir);
WatchKey newKey = dir.register(watcher, new WatchEvent.Kind<?>[] {ENTRY_MODIFY});
if (newKey != myKey) throw new RuntimeException("register did not return existing key");
checkKey(newKey, dir);
System.out.format("update: %s\n", file);
try (OutputStream out = Files.newOutputStream(file, StandardOpenOption.APPEND)) {
out.write("I am a small file".getBytes("UTF-8"));
}
// remove key and check that we got the ENTRY_MODIFY event
takeExpectedKey(watcher, myKey);
checkExpectedEvent(myKey.pollEvents(), StandardWatchEventKinds.ENTRY_MODIFY, name);
System.out.println("OKAY");
// done
Files.delete(file);
}
}
/**
* Test that directory can be registered with more than one watch service and that events don't
* interfere with each other
*/
static void testTwoWatchers(Path dir) throws IOException {
System.out.println("-- Two watchers test --");
FileSystem fs = FileSystems.getDefault();
WatchService watcher1 = fs.newWatchService();
WatchService watcher2 = fs.newWatchService();
try {
Path name1 = fs.getPath("gus1");
Path name2 = fs.getPath("gus2");
// create gus1
Path file1 = dir.resolve(name1);
System.out.format("create %s\n", file1);
Files.createFile(file1);
// register with both watch services (different events)
System.out.println("register for different events");
WatchKey key1 = dir.register(watcher1, new WatchEvent.Kind<?>[] {ENTRY_CREATE});
WatchKey key2 = dir.register(watcher2, new WatchEvent.Kind<?>[] {ENTRY_DELETE});
if (key1 == key2) throw new RuntimeException("keys should be different");
// create gus2
Path file2 = dir.resolve(name2);
System.out.format("create %s\n", file2);
Files.createFile(file2);
// check that key1 got ENTRY_CREATE
takeExpectedKey(watcher1, key1);
checkExpectedEvent(key1.pollEvents(), StandardWatchEventKinds.ENTRY_CREATE, name2);
// check that key2 got zero events
WatchKey key = watcher2.poll();
if (key != null) throw new RuntimeException("key not expected");
// delete gus1
Files.delete(file1);
// check that key2 got ENTRY_DELETE
takeExpectedKey(watcher2, key2);
checkExpectedEvent(key2.pollEvents(), StandardWatchEventKinds.ENTRY_DELETE, name1);
// check that key1 got zero events
key = watcher1.poll();
if (key != null) throw new RuntimeException("key not expected");
// reset for next test
key1.reset();
key2.reset();
// change registration with watcher2 so that they are both
// registered for the same event
System.out.println("register for same event");
key2 = dir.register(watcher2, new WatchEvent.Kind<?>[] {ENTRY_CREATE});
// create file and key2 should be queued
System.out.format("create %s\n", file1);
Files.createFile(file1);
takeExpectedKey(watcher2, key2);
checkExpectedEvent(key2.pollEvents(), StandardWatchEventKinds.ENTRY_CREATE, name1);
System.out.println("OKAY");
} finally {
watcher2.close();
watcher1.close();
}
}