Java Code Examples for java.nio.file.WatchService#close()

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(Path dir, WatchService watcher) {
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            watcher.close();
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
}
 

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(Path dir, WatchService watcher) {
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            watcher.close();
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
}
 

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(Path dir, WatchService watcher) {
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            watcher.close();
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
}
 

private void startEmulator() throws IOException, InterruptedException {
	boolean configPresent = Files.exists(EMULATOR_CONFIG_PATH);
	WatchService watchService = null;

	if (configPresent) {
		watchService = FileSystems.getDefault().newWatchService();
		EMULATOR_CONFIG_DIR.register(watchService, StandardWatchEventKinds.ENTRY_MODIFY);
	}

	try {
		this.emulatorProcess = new ProcessBuilder("gcloud", "beta", "emulators", "pubsub", "start")
				.start();
	}
	catch (IOException ex) {
		fail("Gcloud not found; leaving host/port uninitialized.");
	}

	if (configPresent) {
		updateConfig(watchService);
		watchService.close();
	}
	else {
		createConfig();
	}

}
 

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(Path dir, WatchService watcher) {
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            watcher.close();
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
}
 

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(int id, Path dir, WatchService watcher) {
    System.out.printf("begin handle %d%n", id);
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            System.out.printf("WatchService %d closing ...%n", id);
            watcher.close();
            System.out.printf("WatchService %d closed %n", id);
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
    System.out.printf("end handle %d%n", id);
}
 

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(Path dir, WatchService watcher) {
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            watcher.close();
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
}
 

public void start() throws IOException {
    if (existsAndReadyCheck()) {
        return;
    }

    WatchService watcher = FileSystems.getDefault().newWatchService();
    Path pathToWatch = FileSystems.getDefault().getPath(fileToWatch.getParent());
    register(watcher, pathToWatch);

    try {
        LOG.info(String.format("Migration File Watcher: Watching: %s", fileToWatch.toString()));
        startWatching(watcher);
    } catch (InterruptedException ex) {
        LOG.error("Migration File Watcher: Interrupted!");
    } finally {
        watcher.close();
    }
}
 

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(Path dir, WatchService watcher) {
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            watcher.close();
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
}
 

/**
 * Stress the given WatchService, specifically the cancel method, in
 * the given directory. Closes the WatchService when done.
 */
static void handle(Path dir, WatchService watcher) {
    try {
        try {
            Path file = dir.resolve("anyfile");
            for (int i=0; i<2000; i++) {
                WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
                Files.createFile(file);
                Files.delete(file);
                key.cancel();
            }
        } finally {
            watcher.close();
        }
    } catch (Exception e) {
        e.printStackTrace();
        failed = true;
    }
}
 

/**
 * Returns a task that closes the given WatchService.
 */
static Callable<Void> newCloserTask(WatchService watcher) {
    return () ->  {
        try {
            watcher.close();
            return null;
        } catch (IOException ioe) {
            throw new UncheckedIOException(ioe);
        }
    };
}
 

public File takeHeapDump() throws IOException {
    if (!isTakeHeapDumpSupported()) {
        throw new UnsupportedOperationException();
    }
    String cwd = monitoredVm.findByName(USER_DIR_COUNTER_NAME);
    Path applicationCwd = Paths.get(cwd);
    WatchService watchService = FileSystems.getDefault().newWatchService();
    WatchKey key = applicationCwd.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);
    Runtime.getRuntime().exec(new String[] {"kill", "-USR1", String.valueOf(application.getPid())});
    try {
        Path name = findHeapDumpFile(key);
        if (name == null) {
            key = watchService.poll(20, TimeUnit.SECONDS);
            name = findHeapDumpFile(key);
        }
        watchService.close();
        if (name == null) {
            return null;
        }
        File dumpFile = applicationCwd.resolve(name).toFile();
        waitDumpDone(dumpFile);
        return dumpFile;
    } catch (InterruptedException ex) {
        watchService.close();
        return null;
    }
}
 

@Test
@Ignore
public void testSimple() throws IOException {
  Path rootPath = Paths.get(clusterUri);
  
  WatchService watcher = rootPath.getFileSystem().newWatchService();
  rootPath.register(watcher, 
        new WatchEvent.Kind<?>[] { ENTRY_MODIFY });
  watcher.close();
}
 

@Test(expected=ClosedWatchServiceException.class)
@Ignore
public void testSimpleEx() throws IOException {
  Path rootPath = Paths.get(clusterUri);
  
  WatchService watcher = rootPath.getFileSystem().newWatchService();
  rootPath.register(watcher, 
        new WatchEvent.Kind<?>[] { ENTRY_MODIFY });
  watcher.close();
  // Should throw ClosedWatchServiceException
  watcher.poll();
}
 

public void testEntryDelete() throws IOException, InterruptedException, StfException {
	Path tempDirectory = getTemporaryDirectory();
	WatchService watchService = FileSystems.getDefault().newWatchService();
	try {
		// Create the file before registering the WatchService, so that
		// we don't need to pause before deleting the file
		Path newFilename = Paths.get("ENTRY_DELETE.txt");
		Path newFile = tempDirectory.resolve(newFilename);
		Files.createFile(newFile);
		assertTrue("File was not created", Files.exists(newFile));

		tempDirectory.register(watchService, StandardWatchEventKinds.ENTRY_DELETE);

		Files.delete(newFile);

		WatchKey key = null;
		// We will give it POLL_TIMEOUT_SECONDS seconds, if it hasn't got
		// something by
		// then we assume failure

		key = watchService.poll(POLL_TIMEOUT_SECONDS, TimeUnit.SECONDS);

		assertNotNull("Polling WatchService object returned null", key);

		boolean eventFound = false;

		// Check for exactly one event
		for (WatchEvent<?> event : key.pollEvents()) {
			if (event.kind().equals(StandardWatchEventKinds.ENTRY_DELETE)) {
				// Assert exactly one event
				assertFalse("Duplicate ENTRY_DELETE events delivered for one file deletion", eventFound);
				// Assert filename is correct
				assertEquals(newFilename, (Path) event.context());
				eventFound = true;
			} else {
				fail(event.kind() + " event retured, expected ENTRY_DELETE");
			}
		}
		// Reset the key, to allow for future events
		key.reset();
	} finally {
		watchService.close();
	}
	okForCleanup();
}
 

public void testDirectoryWatcher() throws IOException, StfException {
	Path tempDirectory = getTemporaryDirectory();
	WatchService watchService = null;

	// Obtain watch service for the default file system and register
	// an interest in knowing when files are created
	watchService = FileSystems.getDefault().newWatchService();
	try {
		tempDirectory.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);
		// Hard-coded values of how many files to touch
		int numberOfIterationsRemaining = 10;
		int numberOfFiles = 5;
		int totalFiles = numberOfFiles * numberOfIterationsRemaining;
		long startTime = System.currentTimeMillis();

		// Our variables containing information as to whether we are going
		// to pass
		// or fail
		int filesFound = 0;
		boolean discardedEvents = false;

		LOOP: while (true) {
			WatchKey key;
			
			// Spread out the creating of files, interspersing them with polls.
			if (numberOfIterationsRemaining > 0) {
				createFiles(tempDirectory, numberOfFiles);
				numberOfIterationsRemaining--;
			}

			// Try taking a key off the service, if available (null if not)
			key = watchService.poll();
			if (key != null) {
				// Retrieve each event
				for (WatchEvent<?> event : key.pollEvents()) {
					if (event.kind().equals(StandardWatchEventKinds.ENTRY_CREATE)) {
						// New file found
						filesFound++;
					} else if (event.kind().equals(StandardWatchEventKinds.OVERFLOW)) {
						// Overflow occurred.
						// This is sort of a warning, but expected if we
						// (the JVM?) can't process
						// the events fast enough
						discardedEvents = true;
					}
				}

				// Important to reset the key
				key.reset();
			}

			long duration = System.currentTimeMillis() - startTime;

			// Check if we have received everything we intended to
			// if so, we can break the loop
			if (numberOfIterationsRemaining == 0) {
				if (filesFound == totalFiles) {
					break LOOP;
				}
				if (discardedEvents == true) {
					break LOOP;
				}
			}

			// Check to see if we have been doing this for too long
			// if so, then break the loop
			if (duration > TIMEOUT) {
				fail("Timeout exceeded: " + filesFound + " files found in " + duration + "ms");
				break LOOP;
			}
		}

		System.out.println("Summary: totalfile - " + totalFiles + " , files found " + filesFound);

		if (discardedEvents == false && (totalFiles != filesFound)) {
			fail("No events were knowingly discarded, but the total number of files found does not equal the number created");
		}

		if (discardedEvents == true) {
			System.out.println("Warning, events were discarded.");
		}
	} finally {
		watchService.close();
	}
	okForCleanup();
}
 

public void testEntryModify() throws IOException, InterruptedException, StfException {
	Path tempDirectory = getTemporaryDirectory();
	WatchService watchService = FileSystems.getDefault().newWatchService();
	try {
		Path newFilename = Paths.get("ENTRY_MODIFY.txt");
		Path newFile = tempDirectory.resolve(newFilename);
		Files.createFile(newFile);
		assertTrue("File was not created", Files.exists(newFile));

		// We need to pause so that the implementation on AIX and zOS
		// notices the modification time
		// has changed, which only work to the second apparently.
		try {
			Thread.sleep(2000);
		} catch (InterruptedException e) {

		}

		tempDirectory.register(watchService, StandardWatchEventKinds.ENTRY_MODIFY);

		// Modify file
		OutputStream out = Files.newOutputStream(newFile, StandardOpenOption.WRITE);
		out.write("A".getBytes());
		out.close();

		WatchKey key = null;

		// We will give it POLL_TIMEOUT_SECONDS seconds, if it hasn't got
		// something by
		// then we assume failure

		key = watchService.poll(POLL_TIMEOUT_SECONDS, TimeUnit.SECONDS);

		assertNotNull("Polling WatchService object returned null", key);

		boolean eventFound = false;

		// Check for exactly one event
		for (WatchEvent<?> event : key.pollEvents()) {
			if (event.kind().equals(StandardWatchEventKinds.ENTRY_MODIFY)) {
				// Assert exactly one event
				assertFalse("Duplicate ENTRY_MODIFY events delivered for one file modification", eventFound);
				// Assert filename is correct
				assertEquals(newFilename, (Path) event.context());
				eventFound = true;
			} else {
				fail(event.kind() + " event retured, expected ENTRY_MODIFY");
			}
		}

		// Reset the key, to allow for future events
		key.reset();
	} finally {
		watchService.close();
	}
	okForCleanup();
}
 

public void testMultipleEntryCreate() throws IOException, InterruptedException, StfException {
	Path tempDirectory = getTemporaryDirectory();
	WatchService watchService = FileSystems.getDefault().newWatchService();
	try {
		tempDirectory.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);
		WatchKey key = null;
		for (int iteration = 0; iteration < 10; iteration++) {
			HangNotifier.ping();
			Path newFilename = Paths.get("ENTRY_CREATE" + iteration + ".txt");
			Path newFile = tempDirectory.resolve(newFilename);
			Files.createFile(newFile);
			assertTrue("File was not created", Files.exists(newFile));

			key = null;

			// We will give it POLL_TIMEOUT_SECONDS seconds, if it hasn't got something by
			// then we assume failure

			key = watchService.poll(POLL_TIMEOUT_SECONDS, TimeUnit.SECONDS);
			assertNotNull("Polling WatchService object returned null", key);
			
			boolean eventFound = false;

			// Check for exactly one event
			for (WatchEvent<?> event : key.pollEvents()) {
				if (event.kind().equals(StandardWatchEventKinds.ENTRY_CREATE)) {
					// Assert exactly one event
					assertFalse("Duplicate ENTRY_CREATE events delivered for one file creation", eventFound);
					// Assert filename is correct
					assertEquals(newFilename, (Path) event.context());
					eventFound = true;
				} else {
					fail(event.kind() + " event retured, expected ENTRY_CREATE");
				}
			}

			// Reset the key, to allow for future events
			if (key != null) {
				key.reset();
			}
		}
	} finally {
		watchService.close();
	}
	okForCleanup();
}
 

public void testEntryCreate() throws IOException, InterruptedException, StfException {
	Path tempDirectory = getTemporaryDirectory();
	WatchService watchService = FileSystems.getDefault().newWatchService();
	try {
		tempDirectory.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);
		Path newFilename = Paths.get("ENTRY_CREATE.txt");
		Path newFile = tempDirectory.resolve(newFilename);
		Files.createFile(newFile);
		assertTrue("File was not created", Files.exists(newFile));

		WatchKey key = null;

		// We will give it POLL_TIMEOUT_SECONDS seconds, if it hasn't got something by
		// then we assume failure
		key = watchService.poll(POLL_TIMEOUT_SECONDS, TimeUnit.SECONDS);

		assertNotNull("Polling WatchService object returned null", key);

		boolean eventFound = false;

		// Check for exactly one event
		for (WatchEvent<?> event : key.pollEvents()) {
			if (event.kind().equals(StandardWatchEventKinds.ENTRY_CREATE)) {
				// Assert exactly one event
				assertFalse("Duplicate ENTRY_CREATE events delivered for one file creation", eventFound);
				// Assert filename is correct
				assertEquals(newFilename, (Path) event.context());
				eventFound = true;
			} else {
				fail(event.kind() + " event retured, expected ENTRY_CREATE");
			}
		}

		// Reset the key, to allow for future events
		key.reset();

	} finally {
		watchService.close();
	}
	okForCleanup();
}