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Posted to commits@wicket.apache.org by mg...@apache.org on 2013/06/19 10:07:38 UTC
[2/2] git commit: WICKET-5240 Add ModificationWatcher implementation
that uses NIO2 file system polling
WICKET-5240 Add ModificationWatcher implementation that uses NIO2 file system polling
Project: http://git-wip-us.apache.org/repos/asf/wicket/repo
Commit: http://git-wip-us.apache.org/repos/asf/wicket/commit/5ce35bda
Tree: http://git-wip-us.apache.org/repos/asf/wicket/tree/5ce35bda
Diff: http://git-wip-us.apache.org/repos/asf/wicket/diff/5ce35bda
Branch: refs/heads/master
Commit: 5ce35bdac7b0ee06f3f52a3eb7c46967646d781e
Parents: 7bca70e
Author: Martin Tzvetanov Grigorov <mg...@apache.org>
Authored: Wed Jun 19 10:07:12 2013 +0200
Committer: Martin Tzvetanov Grigorov <mg...@apache.org>
Committed: Wed Jun 19 10:07:12 2013 +0200
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.../util/watch/Nio2ModificationWatcher.java | 201 +++++++++++++++++++
1 file changed, 201 insertions(+)
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http://git-wip-us.apache.org/repos/asf/wicket/blob/5ce35bda/wicket-core/src/main/java/org/apache/wicket/core/util/watch/Nio2ModificationWatcher.java
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diff --git a/wicket-core/src/main/java/org/apache/wicket/core/util/watch/Nio2ModificationWatcher.java b/wicket-core/src/main/java/org/apache/wicket/core/util/watch/Nio2ModificationWatcher.java
new file mode 100644
index 0000000..ab1f099
--- /dev/null
+++ b/wicket-core/src/main/java/org/apache/wicket/core/util/watch/Nio2ModificationWatcher.java
@@ -0,0 +1,201 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.wicket.core.util.watch;
+
+import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.WatchEvent;
+import java.nio.file.WatchKey;
+import java.nio.file.WatchService;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.List;
+
+import org.apache.wicket.Application;
+import org.apache.wicket.ThreadContext;
+import org.apache.wicket.WicketRuntimeException;
+import org.apache.wicket.util.io.IOUtils;
+import org.apache.wicket.util.string.Strings;
+import org.apache.wicket.util.thread.ICode;
+import org.apache.wicket.util.thread.Task;
+import org.apache.wicket.util.time.Duration;
+import org.apache.wicket.util.watch.ModificationWatcher;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * An extension of ModificationWatcher that removes the NotFound entries from
+ * the MarkupCache for newly created files.
+ *
+ * By default MarkupCache registers Markup.NO_MARKUP value for each requested but
+ * not found markup file. Later when the user creates the markup file the MarkupCache
+ * should be notified.
+ *
+ * @since 7.0.0
+ */
+public class Nio2ModificationWatcher extends ModificationWatcher
+{
+ private static final Logger LOG = LoggerFactory.getLogger(Nio2ModificationWatcher.class);
+
+ private final WatchService watchService;
+ private final Application application;
+
+ /** the <code>Task</code> to run */
+ private Task task;
+
+ public Nio2ModificationWatcher(final Application application)
+ {
+ try
+ {
+ this.application = application;
+
+ this.watchService = FileSystems.getDefault().newWatchService();
+ registerWatchables(watchService);
+
+ start(Duration.seconds(2));
+
+ } catch (IOException iox)
+ {
+ throw new WicketRuntimeException("Cannot get the watch service", iox);
+ }
+ }
+
+ @Override
+ public void start(final Duration pollFrequency)
+ {
+ // Construct task with the given polling frequency
+ task = new Task("Wicket-ModificationWatcher-NIO2");
+
+ task.run(pollFrequency, new ICode() {
+ @Override
+ public void run(final Logger log)
+ {
+ checkCreated();
+ checkModified();
+ }
+ });
+ }
+
+ /**
+ * Checks for newly created files and folders.
+ * New folders are registered to be watched.
+ * New files are removed from the MarkupCache because there could be
+ * {@link org.apache.wicket.markup.Markup#NO_MARKUP} (Not Found) entries for them already.
+ */
+ protected void checkCreated()
+ {
+ WatchKey watchKey = watchService.poll();
+ if (watchKey != null)
+ {
+ List<WatchEvent<?>> events = watchKey.pollEvents();
+ for (WatchEvent<?> event : events)
+ {
+ WatchEvent.Kind<?> eventKind = event.kind();
+ Path eventPath = (Path) event.context();
+
+ if (eventKind == ENTRY_CREATE)
+ {
+ if (Files.isDirectory(eventPath))
+ {
+ try
+ {
+ // a directory is created. register it for notifications
+ register(eventPath, watchService);
+ } catch (IOException iox)
+ {
+ LOG.warn("Cannot register folder '" + eventPath + "' to be watched.", iox);
+ }
+ }
+ else
+ {
+ // a new file appeared. we need to clear the NOT_FOUND entry that may be added earlier.
+ // MarkupCache keys are fully qualified URIs
+ String absolutePath = eventPath.toAbsolutePath().toFile().toURI().toString();
+
+ try
+ {
+ ThreadContext.setApplication(application);
+ application.getMarkupSettings()
+ .getMarkupFactory().getMarkupCache().removeMarkup(absolutePath);
+ } finally {
+ ThreadContext.setApplication(null);
+ }
+ }
+ }
+ }
+
+ watchKey.reset();
+ }
+ }
+
+ @Override
+ public void destroy()
+ {
+ if (task != null)
+ {
+ task.interrupt();
+ }
+ IOUtils.closeQuietly(watchService);
+ }
+
+ /**
+ * Registers all classpath folder entries and their subfolders in the {@code #watchService}.
+ *
+ * @param watchService
+ * the watch service that will send the notifications
+ * @throws IOException
+ */
+ private void registerWatchables(final WatchService watchService) throws IOException
+ {
+ String classpath = System.getProperty("java.class.path");
+
+ String[] classPathEntries = Strings.split(classpath, File.pathSeparatorChar);
+ for (String classPathEntry : classPathEntries)
+ {
+ if (classPathEntry.endsWith(".jar") == false)
+ {
+ Path folder = Paths.get(classPathEntry);
+ if (Files.isDirectory(folder))
+ {
+ register(folder, watchService);
+
+ Files.walkFileTree(folder, new SimpleFileVisitor<Path>() {
+ @Override
+ public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException
+ {
+ register(dir, watchService);
+ return FileVisitResult.CONTINUE;
+ }
+ });
+ }
+ }
+ }
+ }
+
+ private void register(final Path folder, final WatchService watchService) throws IOException
+ {
+ LOG.debug("Registering folder '{}'", folder);
+ folder.register(watchService, ENTRY_CREATE);
+ }
+}