1 files changed, 121 insertions, 0 deletions
diff --git a/sdnr/wireless-transport/code-Carbon-SR1/apps/devicemanager/impl/src/main/java/org/opendaylight/mwtn/base/internalTypes/FileWatchdog.java b/sdnr/wireless-transport/code-Carbon-SR1/apps/devicemanager/impl/src/main/java/org/opendaylight/mwtn/base/internalTypes/FileWatchdog.java
new file mode 100644
index 00000000..e3b0ef54
--- /dev/null
+++ b/sdnr/wireless-transport/code-Carbon-SR1/apps/devicemanager/impl/src/main/java/org/opendaylight/mwtn/base/internalTypes/FileWatchdog.java
@@ -0,0 +1,121 @@
+/*
+ * 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.opendaylight.mwtn.base.internalTypes;
+
+import java.io.File;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Check every now and then that a certain file has not changed. If it has, then
+ * call the {@link #doOnChange} method.
+ *
+ * @author JunHo Yoon
+ * @since 3.1.1
+ */
+public abstract class FileWatchdog extends Thread {
+	private static final Logger LOGGER = LoggerFactory.getLogger(FileWatchdog.class);
+	/**
+	 * The default delay between every file modification check, set to 60
+	 * seconds.
+	 */
+	public static final long DEFAULT_DELAY = 60000;
+	/**
+	 * The name of the file to observe for changes.
+	 */
+	private String filename;
+
+	/**
+	 * The delay to observe between every check. By default set
+	 * {@link #DEFAULT_DELAY}.
+	 */
+	private long delay = DEFAULT_DELAY;
+
+	private File file;
+	private long lastModified = 0;
+	private boolean warnedAlready = false;
+	private boolean interrupted = false;
+
+	protected  FileWatchdog(String filename) {
+		this.filename = filename;
+		file = new File(filename);
+		setDaemon(true);
+		checkAndConfigure();
+	}
+
+	/**
+	 * Set the delay to observe between each check of the file changes.
+	 *
+	 * @param delay
+	 *            the frequency of file watch.
+	 */
+	public  void setDelay(long delay) {
+		this.delay = delay;
+	}
+
+	/**
+	 * abstract method to be run when the file is changed.
+	 */
+	protected abstract void doOnChange();
+
+	protected  void checkAndConfigure() {
+		boolean fileExists;
+		try {
+			fileExists = file.exists();
+		} catch (SecurityException e) {
+			LOGGER.warn("Was not allowed to read check file existence, file:[" + filename + "].");
+			interrupted = true; // there is no point in continuing
+			return;
+		}
+
+		if (fileExists) {
+			long l = file.lastModified(); // this can also throw a
+			if (lastModified ==0) {
+				lastModified = l; // is very unlikely.
+			}
+			if (l > lastModified) { // however, if we reached this point this
+				lastModified = l; // is very unlikely.
+				doOnChange();
+				warnedAlready = false;
+			}
+		} else {
+			if (!warnedAlready) {
+				LOGGER.debug("[" + filename + "] does not exist.");
+				warnedAlready = true;
+			}
+		}
+	}
+
+	/*
+	 * (non-Javadoc)
+	 *
+	 * @see java.lang.Thread#run()
+	 */
+	@Override
+	public  void run() {
+		while (!interrupted && !isInterrupted()) {
+			try {
+				Thread.sleep(delay);
+			} catch (InterruptedException e) {
+
+			}
+			checkAndConfigure();
+		}
+	}
+}
+\ No newline at end of file