Created FileWatcher.

src/main/java/info/fetter/logstashforwarder/FileWatcher.java

@@ -0,0 +1,136 @@
+package info.fetter.logstashforwarder;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.io.FilenameUtils;
+import org.apache.commons.io.filefilter.FileFilterUtils;
+import org.apache.commons.io.filefilter.IOFileFilter;
+import org.apache.commons.io.filefilter.WildcardFileFilter;
+import org.apache.commons.io.monitor.FileAlterationListener;
+import org.apache.commons.io.monitor.FileAlterationObserver;
+import org.apache.log4j.Logger;
+
+/*
+ * Copyright 2015 Didier Fetter
+ *
+ * Licensed 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.
+ *
+ */
+
+public class FileWatcher implements FileAlterationListener {
+	private static final Logger logger = Logger.getLogger(FileWatcher.class);
+	private List<FileAlterationObserver> observerList = new ArrayList<FileAlterationObserver>();
+	static final int ONE_DAY = 24 * 3600 * 1000;
+	private long cutoff;
+	
+	public FileWatcher(long deadTime) {
+		cutoff = System.currentTimeMillis() - deadTime;
+	}
+	
+	public FileWatcher() {
+		this(ONE_DAY);
+	}
+
+	public void addFilesToWatch(String fileToWatch) {
+		try {
+			if(fileToWatch.equals("-")) {
+				watchStdIn();
+			} else if(fileToWatch.contains("*")) {
+				watchWildCardFiles(fileToWatch);
+			} else {
+				watchFile(fileToWatch);
+			}
+		} catch(Exception e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	private void watchFile(String fileToWatch) throws Exception {
+		logger.info("Watching file : " + new File(fileToWatch).getAbsolutePath());
+		String directory = FilenameUtils.getFullPath(fileToWatch);
+		String fileName = FilenameUtils.getName(fileToWatch); 
+		IOFileFilter fileFilter = FileFilterUtils.and(
+				FileFilterUtils.fileFileFilter(),
+				FileFilterUtils.nameFileFilter(fileName),
+				FileFilterUtils.ageFileFilter(cutoff, false));
+		FileAlterationObserver observer = new FileAlterationObserver(new File(directory), fileFilter);
+		observer.addListener(this);
+		observerList.add(observer);
+		observer.initialize();
+	}
+
+	private void watchWildCardFiles(String filesToWatch) throws Exception {
+		logger.info("Watching wildcard files : " + filesToWatch);
+		String directory = FilenameUtils.getFullPath(filesToWatch);
+		String wildcard = FilenameUtils.getName(filesToWatch);
+		logger.trace("Directory : " + new File(directory).getAbsolutePath() + ", wildcard : " + wildcard);
+		IOFileFilter fileFilter = FileFilterUtils.and(
+				FileFilterUtils.fileFileFilter(),
+				new WildcardFileFilter(wildcard),
+				FileFilterUtils.ageFileFilter(cutoff, false));
+		FileAlterationObserver observer = new FileAlterationObserver(new File(directory), fileFilter);
+		observer.addListener(this);
+		observerList.add(observer);
+		observer.initialize();
+	}
+
+
+
+	private void watchStdIn() {
+		logger.info("Watching stdin : not implemented yet");
+	}
+
+	public void onDirectoryChange(File directory) {
+		// Do nothing
+	}
+
+	public void onDirectoryCreate(File directory) {
+		// Do nothing
+	}
+
+	public void onDirectoryDelete(File directory) {
+		// Do nothing
+	}
+
+	public void onFileChange(File file) {
+		logger.debug("Change detected on file : " + file.getAbsolutePath());	
+	}
+
+	public void onFileCreate(File file) {
+		logger.debug("Create detected on file : " + file.getAbsolutePath());		
+	}
+
+	public void onFileDelete(File file) {
+		logger.debug("Delete detected on file : " + file.getAbsolutePath());
+	}
+
+	public void onStart(FileAlterationObserver observer) {
+		// TODO Auto-generated method stub
+
+	}
+
+	public void onStop(FileAlterationObserver observer) {
+		// TODO Auto-generated method stub
+
+	}
+
+	public void checkFiles() {
+		logger.debug("Checking files");
+		for(FileAlterationObserver observer : observerList) {
+			observer.checkAndNotify();
+		}
+	}
+
+}