Java tutorial
/* * 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.apache.commons.net.ftp.parser; import java.text.ParseException; import java.util.List; import java.util.ListIterator; import org.apache.commons.net.ftp.FTPClientConfig; import org.apache.commons.net.ftp.FTPFile; /** * Implementation FTPFileEntryParser and FTPFileListParser for standard * Unix Systems. * * This class is based on the logic of Daniel Savarese's * DefaultFTPListParser, but adapted to use regular expressions and to fit the * new FTPFileEntryParser interface. * @version $Id: UnixFTPEntryParser.java 1489361 2013-06-04 09:48:36Z sebb $ * @see org.apache.commons.net.ftp.FTPFileEntryParser FTPFileEntryParser (for usage instructions) */ public class UnixFTPEntryParser extends ConfigurableFTPFileEntryParserImpl { static final String DEFAULT_DATE_FORMAT = "MMM d yyyy"; //Nov 9 2001 static final String DEFAULT_RECENT_DATE_FORMAT = "MMM d HH:mm"; //Nov 9 20:06 static final String NUMERIC_DATE_FORMAT = "yyyy-MM-dd HH:mm"; //2001-11-09 20:06 /** * Some Linux distributions are now shipping an FTP server which formats * file listing dates in an all-numeric format: * <code>"yyyy-MM-dd HH:mm</code>. * This is a very welcome development, and hopefully it will soon become * the standard. However, since it is so new, for now, and possibly * forever, we merely accomodate it, but do not make it the default. * <p> * For now end users may specify this format only via * <code>UnixFTPEntryParser(FTPClientConfig)</code>. * Steve Cohen - 2005-04-17 */ public static final FTPClientConfig NUMERIC_DATE_CONFIG = new FTPClientConfig(FTPClientConfig.SYST_UNIX, NUMERIC_DATE_FORMAT, null, null, null, null); /** * this is the regular expression used by this parser. * * Permissions: * r the file is readable * w the file is writable * x the file is executable * - the indicated permission is not granted * L mandatory locking occurs during access (the set-group-ID bit is * on and the group execution bit is off) * s the set-user-ID or set-group-ID bit is on, and the corresponding * user or group execution bit is also on * S undefined bit-state (the set-user-ID bit is on and the user * execution bit is off) * t the 1000 (octal) bit, or sticky bit, is on [see chmod(1)], and * execution is on * T the 1000 bit is turned on, and execution is off (undefined bit- * state) * e z/OS external link bit */ private static final String REGEX = "([bcdelfmpSs-])" + "(((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-]))((r|-)(w|-)([xsStTL-])))\\+?\\s*" + "(\\d+)\\s+" // link count + "(?:(\\S+(?:\\s\\S+)*?)\\s+)?" // owner name (optional spaces) + "(?:(\\S+(?:\\s\\S+)*)\\s+)?" // group name (optional spaces) + "(\\d+(?:,\\s*\\d+)?)\\s+" // size or n,m /* * numeric or standard format date: * yyyy-mm-dd (expecting hh:mm to follow) * MMM [d]d * [d]d MMM * N.B. use non-space for MMM to allow for languages such as German which use * diacritics (e.g. umlaut) in some abbreviations. */ + "((?:\\d+[-/]\\d+[-/]\\d+)|(?:\\S{3}\\s+\\d{1,2})|(?:\\d{1,2}\\s+\\S{3}))\\s+" /* year (for non-recent standard format) - yyyy or time (for numeric or recent standard format) [h]h:mm */ + "(\\d+(?::\\d+)?)\\s+" + "(\\S*)(\\s*.*)"; // the rest /** * The default constructor for a UnixFTPEntryParser object. * * @exception IllegalArgumentException * Thrown if the regular expression is unparseable. Should not be seen * under normal conditions. It it is seen, this is a sign that * <code>REGEX</code> is not a valid regular expression. */ public UnixFTPEntryParser() { this(null); } /** * This constructor allows the creation of a UnixFTPEntryParser object with * something other than the default configuration. * * @param config The {@link FTPClientConfig configuration} object used to * configure this parser. * @exception IllegalArgumentException * Thrown if the regular expression is unparseable. Should not be seen * under normal conditions. It it is seen, this is a sign that * <code>REGEX</code> is not a valid regular expression. * @since 1.4 */ public UnixFTPEntryParser(FTPClientConfig config) { super(REGEX); configure(config); } /** * Preparse the list to discard "total nnn" lines */ @Override public List<String> preParse(List<String> original) { ListIterator<String> iter = original.listIterator(); while (iter.hasNext()) { String entry = iter.next(); if (entry.matches("^total \\d+$")) { // NET-389 iter.remove(); } } return original; } /** * Parses a line of a unix (standard) FTP server file listing and converts * it into a usable format in the form of an <code> FTPFile </code> * instance. If the file listing line doesn't describe a file, * <code> null </code> is returned, otherwise a <code> FTPFile </code> * instance representing the files in the directory is returned. * <p> * @param entry A line of text from the file listing * @return An FTPFile instance corresponding to the supplied entry */ // @Override public FTPFile parseFTPEntry(String entry) { FTPFile file = new FTPFile(); file.setRawListing(entry); int type; boolean isDevice = false; if (matches(entry)) { String typeStr = group(1); String hardLinkCount = group(15); String usr = group(16); String grp = group(17); String filesize = group(18); String datestr = group(19) + " " + group(20); String name = group(21); String endtoken = group(22); try { file.setTimestamp(super.parseTimestamp(datestr)); } catch (ParseException e) { // intentionally do nothing } // A 'whiteout' file is an ARTIFICIAL entry in any of several types of // 'translucent' filesystems, of which a 'union' filesystem is one. // bcdelfmpSs- switch (typeStr.charAt(0)) { case 'd': type = FTPFile.DIRECTORY_TYPE; break; case 'e': // NET-39 => z/OS external link type = FTPFile.SYMBOLIC_LINK_TYPE; break; case 'l': type = FTPFile.SYMBOLIC_LINK_TYPE; break; case 'b': case 'c': isDevice = true; type = FTPFile.FILE_TYPE; // TODO change this if DEVICE_TYPE implemented break; case 'f': case '-': type = FTPFile.FILE_TYPE; break; default: // e.g. ? and w = whiteout type = FTPFile.UNKNOWN_TYPE; } file.setType(type); int g = 4; for (int access = 0; access < 3; access++, g += 4) { // Use != '-' to avoid having to check for suid and sticky bits file.setPermission(access, FTPFile.READ_PERMISSION, (!group(g).equals("-"))); file.setPermission(access, FTPFile.WRITE_PERMISSION, (!group(g + 1).equals("-"))); String execPerm = group(g + 2); if (!execPerm.equals("-") && !Character.isUpperCase(execPerm.charAt(0))) { file.setPermission(access, FTPFile.EXECUTE_PERMISSION, true); } else { file.setPermission(access, FTPFile.EXECUTE_PERMISSION, false); } } if (!isDevice) { try { file.setHardLinkCount(Integer.parseInt(hardLinkCount)); } catch (NumberFormatException e) { // intentionally do nothing } } file.setUser(usr); file.setGroup(grp); try { file.setSize(Long.parseLong(filesize)); } catch (NumberFormatException e) { // intentionally do nothing } if (null == endtoken) { file.setName(name); } else { // oddball cases like symbolic links, file names // with spaces in them. name += endtoken; if (type == FTPFile.SYMBOLIC_LINK_TYPE) { int end = name.indexOf(" -> "); // Give up if no link indicator is present if (end == -1) { file.setName(name); } else { file.setName(name.substring(0, end)); file.setLink(name.substring(end + 4)); } } else { file.setName(name); } } return file; } return null; } /** * Defines a default configuration to be used when this class is * instantiated without a {@link FTPClientConfig FTPClientConfig} * parameter being specified. * @return the default configuration for this parser. */ @Override protected FTPClientConfig getDefaultConfiguration() { return new FTPClientConfig(FTPClientConfig.SYST_UNIX, DEFAULT_DATE_FORMAT, DEFAULT_RECENT_DATE_FORMAT, null, null, null); } }