/*
- * Copyright 2006 the original author or authors.
+ * Copyright 2005-2010 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-
package org.wamblee.io;
import java.io.File;
import java.io.FileFilter;
-import java.util.ArrayList;
+
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
-import java.util.List;
import java.util.Map;
import java.util.Set;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
+import java.util.logging.Logger;
/**
- * Monitors a directory for changes.
+ * Monitors a directory for changes. The currernt implementation only checks
+ * files not directories and does not check for modifications in subdirectories.
*
* @author Erik Brakkee
*/
public class DirectoryMonitor {
+ private static final Logger LOG = Logger.getLogger(DirectoryMonitor.class
+ .getName());
+
+ private File directory;
+
+ private FileFilter filter;
+
+ private Listener listener;
+
+ private Map<File, Date> contents;
+
+ /**
+ * Creates a new DirectoryMonitor object.
+ *
+ */
+ public DirectoryMonitor(File aDirectory, FileFilter aFilefilter,
+ Listener aListener) {
+ directory = aDirectory;
+
+ if (!directory.isDirectory()) {
+ throw new IllegalArgumentException("Directory '" + directory +
+ "' does not exist");
+ }
+
+ filter = aFilefilter;
+ listener = aListener;
+ contents = new HashMap<File, Date>();
+ }
+
+ /**
+ * Polls the directory for changes and notifies the listener of any changes.
+ * In case of any exceptions thrown by the listener while handling the
+ * changes, the next call to this method will invoked the listeners again
+ * for the same changes.
+ */
+ public void poll() {
+ LOG.fine("Polling " + directory);
+
+ Map<File, Date> newContents = new HashMap<File, Date>();
+ File[] files = directory.listFiles(filter);
+
+ // Check deleted files.
+ Set<File> deletedFiles = new HashSet<File>(contents.keySet());
+
+ for (File file : files) {
+ if (file.isFile()) {
+ if (contents.containsKey(file)) {
+ deletedFiles.remove(file);
+ }
+ }
+ }
+
+ for (File file : deletedFiles) {
+ listener.fileDeleted(file);
+ }
+
+ for (File file : files) {
+ if (file.isFile()) {
+ if (contents.containsKey(file)) {
+ Date oldDate = contents.get(file);
+
+ if (file.lastModified() != oldDate.getTime()) {
+ listener.fileChanged(file);
+ } else {
+ // No change.
+ }
+
+ newContents.put(file, new Date(file.lastModified()));
+ } else {
+ listener.fileCreated(file);
+ newContents.put(file, new Date(file.lastModified()));
+ }
+ }
+ }
+
+ contents = newContents;
+ }
+
+ /**
+ * Listener interface to be provided by users of the directory monitor to
+ * get notified of changes.
+ *
+ * @author Erik Brakkee
+ */
+ public static interface Listener {
+ /**
+ * @param aFile
+ * File that has changed.
+ */
+ void fileChanged(File aFile);
- private static final Log LOG = LogFactory.getLog(DirectoryMonitor.class);
-
- public static interface Listener {
-
- void fileChanged(File aFile);
-
- void fileCreated(File aFile);
-
- void fileDeleted(File aFile);
- };
-
- private File _directory;
- private FileFilter _filter;
- private Listener _listener;
- private Map<File, Date> _contents;
-
- public DirectoryMonitor(File aDirectory, FileFilter aFilefilter,
- Listener aListener) {
- _directory = aDirectory;
- if (!_directory.isDirectory()) {
- throw new IllegalArgumentException("Directory '" + _directory
- + "' does not exist");
- }
- _filter = aFilefilter;
- _listener = aListener;
- _contents = new HashMap<File, Date>();
- }
-
- /**
- * Polls the directory for changes and notifies the listener of any changes.
- * In case of any exceptions thrown by the listener while handling the changes,
- * the next call to this method will invoked the listeners again for the same changes.
- */
- public void poll() {
- LOG.debug("Polling " + _directory);
- Map<File, Date> newContents = new HashMap<File, Date>();
- File[] files = _directory.listFiles(_filter);
-
- // Check deleted files.
- Set<File> deletedFiles = new HashSet<File>(_contents.keySet());
- for (File file : files) {
- if (file.isFile()) {
- if (_contents.containsKey(file)) {
- deletedFiles.remove(file);
- }
- }
- }
- for (File file : deletedFiles) {
- _listener.fileDeleted(file);
- }
-
- for (File file : files) {
- if (file.isFile()) {
- if (_contents.containsKey(file)) {
- Date oldDate = _contents.get(file);
- if (file.lastModified() != oldDate.getTime()) {
- _listener.fileChanged(file);
- } else {
- // No change.
- }
- newContents.put(file, new Date(file.lastModified()));
- } else {
- _listener.fileCreated(file);
- newContents.put(file, new Date(file.lastModified()));
- }
- }
- }
-
- _contents = newContents;
- }
+ /**
+ * @param aFile
+ * File that was created.
+ */
+ void fileCreated(File aFile);
+ /**
+ * @param aFile
+ * File that was deleted.
+ */
+ void fileDeleted(File aFile);
+ }
}
git://wamblee.org / utils / blobdiff