Java tutorial
/* * ome.io.nio.AbstractFileSystemService * * Copyright 2006 University of Dundee. All rights reserved. * Use is subject to license terms supplied in LICENSE.txt */ package ome.io.nio; import java.io.File; import java.util.Formatter; import org.apache.commons.io.FilenameUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * @author callan * */ public class AbstractFileSystemService { /** The logger for this particular class */ private static Log log = LogFactory.getLog(AbstractFileSystemService.class); public final static String ROOT_DEFAULT = File.separator + "OMERO" + File.separator; public final static String PIXELS_PATH = "Pixels" + File.separator; public final static String FILES_PATH = "Files" + File.separator; public final static String THUMBNAILS_PATH = "Thumbnails" + File.separator; private final String root; public AbstractFileSystemService(String path) { File rootDirectory = new File(path); if (!rootDirectory.isDirectory() || !rootDirectory.canRead() || !rootDirectory.canWrite()) { throw new IllegalArgumentException( "Invalid directory specified for file system service." + rootDirectory); } this.root = rootDirectory.getAbsolutePath(); if (log.isDebugEnabled()) { log.warn("Using root path: '" + this.root + "'"); } } /** * Makes sure that for a given path, it's subpath exists. For example, given * the path "/foo/bar/foobar.txt" the method will make sure the directory * structure "/foo/bar" exists. * * @param path * the path to check for subpath existance. */ protected void createSubpath(String path) { File file = new File(path); if (!file.exists()) { File directory = new File(file.getParent()); if (!directory.exists()) { directory.mkdirs(); } } } /** * Returns a numbered path relative to the root of this service, but is * ignorant of FS and similar constructs. For example, given an id of 123456 * this will return "ROOT/Pixels/Dir-123/Dir-456/123456" * * Should be marked protected in 4.4 because assumptions on the existence * of this file can be dangerous. * * @param id * @return */ public /*protected*/ String getPixelsPath(Long id) { return getPath(PIXELS_PATH, id); } /** * Returns a numbered path relative to the root of this service, but is * ignorant of FS and similar constructs. For example, given an id of 123456 * this will return "ROOT/Files/Dir-123/Dir-456/123456" * * Should be marked protected in 4.4 because assumptions on the existence * of this file can be dangerous. * * @param id * @return */ public /*protected*/ String getFilesPath(Long id) { return getPath(FILES_PATH, id); } /** * Returns a numbered path relative to the root of this service, but is * ignorant of FS and similar constructs. For example, given an id of 123456 * this will return "ROOT/Thumbnails/Dir-123/Dir-456/123456" * * Should be marked protected in 4.4 because assumptions on the existence * of this file can be dangerous. * * @param id * @return */ public /*protected*/ String getThumbnailPath(Long id) { return getPath(THUMBNAILS_PATH, id); } private String getPath(String prefix, Long id) { String suffix = ""; Long remaining = id; Long dirno = 0L; if (id == null) { throw new NullPointerException("Expecting a not-null id."); } while (remaining > 999) { remaining /= 1000; if (remaining > 0) { Formatter formatter = new Formatter(); dirno = remaining % 1000; suffix = formatter.format("Dir-%03d", dirno).out().toString() + File.separator + suffix; } } String path = FilenameUtils.concat(root, prefix + suffix + id); return path; } }