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 * 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
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 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.commons.configuration2.reloading;

import org.apache.commons.configuration2.ex.ConfigurationRuntimeException;
import org.apache.commons.configuration2.io.FileHandler;
import org.apache.commons.configuration2.io.FileSystem;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemManager;
import org.apache.commons.vfs2.VFS;

A file-based reloading strategy that uses Commons VFS to determine when a file was changed.

This reloading strategy is very similar to FileHandlerReloadingDetector, except for the fact that it uses VFS and thus can deal with a variety of different configuration sources.

This strategy only works with FileConfiguration instances.

Since:1.7
/** * <p> * A file-based reloading strategy that uses <a * href="https://commons.apache.org/vfs/">Commons VFS</a> to determine when a * file was changed. * </p> * <p> * This reloading strategy is very similar to * {@link FileHandlerReloadingDetector}, except for the fact that it uses VFS * and thus can deal with a variety of different configuration sources. * </p> * <p> * This strategy only works with FileConfiguration instances. * </p> * * @since 1.7 */
public class VFSFileHandlerReloadingDetector extends FileHandlerReloadingDetector {
Stores the logger.
/** Stores the logger.*/
private final Log log = LogFactory.getLog(getClass());
Creates a new instance of VFSFileHandlerReloadingDetector and initializes it with an empty FileHandler object.
/** * Creates a new instance of {@code VFSFileHandlerReloadingDetector} and * initializes it with an empty {@code FileHandler} object. */
public VFSFileHandlerReloadingDetector() { super(); }
Creates a new instance of VFSFileHandlerReloadingDetector and initializes it with the given FileHandler object and the given refresh delay.
Params:
  • handler – the FileHandler
  • refreshDelay – the refresh delay
/** * Creates a new instance of {@code VFSFileHandlerReloadingDetector} and * initializes it with the given {@code FileHandler} object and the given * refresh delay. * * @param handler the {@code FileHandler} * @param refreshDelay the refresh delay */
public VFSFileHandlerReloadingDetector(final FileHandler handler, final long refreshDelay) { super(handler, refreshDelay); }
Creates a new instance of VFSFileHandlerReloadingDetector and initializes it with the given FileHandler object.
Params:
  • handler – the FileHandler
/** * Creates a new instance of {@code VFSFileHandlerReloadingDetector} and * initializes it with the given {@code FileHandler} object. * * @param handler the {@code FileHandler} */
public VFSFileHandlerReloadingDetector(final FileHandler handler) { super(handler); }
{@inheritDoc} This implementation uses Commons VFS to obtain a FileObject and read the date of the last modification.
/** * {@inheritDoc} This implementation uses Commons VFS to obtain a * {@code FileObject} and read the date of the last modification. */
@Override protected long getLastModificationDate() { final FileObject file = getFileObject(); try { if (file == null || !file.exists()) { return 0; } return file.getContent().getLastModifiedTime(); } catch (final FileSystemException ex) { log.error("Unable to get last modified time for" + file.getName().getURI(), ex); return 0; } }
Returns the file that is monitored by this strategy. Note that the return value can be null under some circumstances.
Returns:the monitored file
/** * Returns the file that is monitored by this strategy. Note that the return * value can be <b>null </b> under some circumstances. * * @return the monitored file */
protected FileObject getFileObject() { if (!getFileHandler().isLocationDefined()) { return null; } try { final FileSystemManager fsManager = VFS.getManager(); final String uri = resolveFileURI(); if (uri == null) { throw new ConfigurationRuntimeException("Unable to determine file to monitor"); } return fsManager.resolveFile(uri); } catch (final FileSystemException fse) { final String msg = "Unable to monitor " + getFileHandler().getURL().toString(); log.error(msg); throw new ConfigurationRuntimeException(msg, fse); } }
Resolves the URI of the monitored file.
Returns:the URI of the monitored file or null if it cannot be resolved
/** * Resolves the URI of the monitored file. * * @return the URI of the monitored file or <b>null</b> if it cannot be * resolved */
protected String resolveFileURI() { final FileSystem fs = getFileHandler().getFileSystem(); final String uri = fs.getPath(null, getFileHandler().getURL(), getFileHandler() .getBasePath(), getFileHandler().getFileName()); return uri; } }