DefaultFTPFileEntryParserFactory.java
/*
* 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.util.regex.Pattern;
import org.apache.commons.net.ftp.Configurable;
import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFileEntryParser;
/**
* This is the default implementation of the FTPFileEntryParserFactory interface. This is the implementation that will be used by
* org.apache.commons.net.ftp.FTPClient.listFiles() if no other implementation has been specified.
*
* @see org.apache.commons.net.ftp.FTPClient#listFiles
* @see org.apache.commons.net.ftp.FTPClient#setParserFactory
*/
public class DefaultFTPFileEntryParserFactory implements FTPFileEntryParserFactory {
// Match a plain Java Identifier
private static final String JAVA_IDENTIFIER = "\\p{javaJavaIdentifierStart}(\\p{javaJavaIdentifierPart})*";
// Match a qualified name, e.g. a.b.c.Name - but don't allow the default package as that would allow "VMS"/"UNIX" etc.
private static final String JAVA_QUALIFIED_NAME = "(" + JAVA_IDENTIFIER + "\\.)+" + JAVA_IDENTIFIER;
// Create the pattern, as it will be reused many times
private static final Pattern JAVA_QUALIFIED_NAME_PATTERN = Pattern.compile(JAVA_QUALIFIED_NAME);
/**
* <p>
* Implementation extracts a key from the supplied {@link FTPClientConfig FTPClientConfig} parameter and creates an object implementing the interface
* FTPFileEntryParser and uses the supplied configuration to configure it.
* </p>
* <p>
* Note that this method will generally not be called in scenarios that call for autodetection of parser type but rather, for situations where the user
* knows that the server uses a non-default configuration and knows what that configuration is.
* </p>
*
* @param config A {@link FTPClientConfig FTPClientConfig} used to configure the parser created
*
* @return the {@link FTPFileEntryParser} so created.
* @throws ParserInitializationException Thrown on any exception in instantiation
* @throws NullPointerException if {@code config} is {@code null}
* @since 1.4
*/
@Override
public FTPFileEntryParser createFileEntryParser(final FTPClientConfig config) throws ParserInitializationException {
final String key = config.getServerSystemKey();
return createFileEntryParser(key, config);
}
/**
* This default implementation of the FTPFileEntryParserFactory interface works according to the following logic: First it attempts to interpret the
* supplied key as a fully qualified classname (default package is not allowed) of a class implementing the FTPFileEntryParser interface. If that succeeds,
* a parser object of this class is instantiated and is returned; otherwise it attempts to interpret the key as an identirier commonly used by the FTP SYST
* command to identify systems.
* <p>
* If <code>key</code> is not recognized as a fully qualified classname known to the system, this method will then attempt to see whether it <b>contains</b>
* a string identifying one of the known parsers. This comparison is <b>case-insensitive</b>. The intent here is where possible, to select as keys strings
* which are returned by the SYST command on the systems which the corresponding parser successfully parses. This enables this factory to be used in the
* auto-detection system.
*
* @param key should be a fully qualified classname corresponding to a class implementing the FTPFileEntryParser interface<br>
* OR<br>
* a string containing (case-insensitively) one of the following keywords:
* <ul>
* <li>{@link FTPClientConfig#SYST_UNIX UNIX}</li>
* <li>{@link FTPClientConfig#SYST_NT WINDOWS}</li>
* <li>{@link FTPClientConfig#SYST_OS2 OS/2}</li>
* <li>{@link FTPClientConfig#SYST_OS400 OS/400}</li>
* <li>{@link FTPClientConfig#SYST_AS400 AS/400}</li>
* <li>{@link FTPClientConfig#SYST_VMS VMS}</li>
* <li>{@link FTPClientConfig#SYST_MVS MVS}</li>
* <li>{@link FTPClientConfig#SYST_NETWARE NETWARE}</li>
* <li>{@link FTPClientConfig#SYST_L8 TYPE:L8}</li>
* </ul>
* @return the FTPFileEntryParser corresponding to the supplied key.
* @throws ParserInitializationException thrown if for any reason the factory cannot resolve the supplied key into an FTPFileEntryParser.
* @see FTPFileEntryParser
*/
@Override
public FTPFileEntryParser createFileEntryParser(final String key) {
if (key == null) {
throw new ParserInitializationException("Parser key cannot be null");
}
return createFileEntryParser(key, null);
}
// Common method to process both key and config parameters.
private FTPFileEntryParser createFileEntryParser(final String key, final FTPClientConfig config) {
FTPFileEntryParser parser = null;
// Is the key a possible class name?
if (JAVA_QUALIFIED_NAME_PATTERN.matcher(key).matches()) {
try {
final Class<?> parserClass = Class.forName(key);
try {
parser = (FTPFileEntryParser) parserClass.newInstance();
} catch (final ClassCastException e) {
throw new ParserInitializationException(
parserClass.getName() + " does not implement the interface " + "org.apache.commons.net.ftp.FTPFileEntryParser.", e);
} catch (final Exception | ExceptionInInitializerError e) {
throw new ParserInitializationException("Error initializing parser", e);
}
} catch (final ClassNotFoundException e) {
// OK, assume it is an alias
}
}
if (parser == null) { // Now try for aliases
final String ukey = key.toUpperCase(java.util.Locale.ENGLISH);
if (ukey.contains(FTPClientConfig.SYST_UNIX_TRIM_LEADING)) {
parser = new UnixFTPEntryParser(config, true);
}
// must check this after SYST_UNIX_TRIM_LEADING as it is a substring of it
else if (ukey.contains(FTPClientConfig.SYST_UNIX)) {
parser = new UnixFTPEntryParser(config, false);
} else if (ukey.contains(FTPClientConfig.SYST_VMS)) {
parser = new VMSVersioningFTPEntryParser(config);
} else if (ukey.contains(FTPClientConfig.SYST_NT)) {
parser = createNTFTPEntryParser(config);
} else if (ukey.contains(FTPClientConfig.SYST_OS2)) {
parser = new OS2FTPEntryParser(config);
} else if (ukey.contains(FTPClientConfig.SYST_OS400) || ukey.contains(FTPClientConfig.SYST_AS400)) {
parser = createOS400FTPEntryParser(config);
} else if (ukey.contains(FTPClientConfig.SYST_MVS)) {
parser = new MVSFTPEntryParser(); // Does not currently support config parameter
} else if (ukey.contains(FTPClientConfig.SYST_NETWARE)) {
parser = new NetwareFTPEntryParser(config);
} else if (ukey.contains(FTPClientConfig.SYST_MACOS_PETER)) {
parser = new MacOsPeterFTPEntryParser(config);
} else if (ukey.contains(FTPClientConfig.SYST_L8)) {
// L8 normally means Unix, but move it to the end for some L8 systems that aren't.
// This check should be last!
parser = new UnixFTPEntryParser(config);
} else {
throw new ParserInitializationException("Unknown parser type: " + key);
}
}
if (parser instanceof Configurable) {
((Configurable) parser).configure(config);
}
return parser;
}
public FTPFileEntryParser createMVSEntryParser() {
return new MVSFTPEntryParser();
}
public FTPFileEntryParser createNetwareFTPEntryParser() {
return new NetwareFTPEntryParser();
}
public FTPFileEntryParser createNTFTPEntryParser() {
return createNTFTPEntryParser(null);
}
/**
* Creates an NT FTP parser: if the config exists, and the system key equals {@link FTPClientConfig#SYST_NT} then a plain {@link NTFTPEntryParser} is used,
* otherwise a composite of {@link NTFTPEntryParser} and {@link UnixFTPEntryParser} is used.
*
* @param config the config to use, may be {@code null}
* @return the parser
*/
private FTPFileEntryParser createNTFTPEntryParser(final FTPClientConfig config) {
if (config != null && FTPClientConfig.SYST_NT.equals(config.getServerSystemKey())) {
return new NTFTPEntryParser(config);
}
// clone the config as it may be changed by the parsers (NET-602)
final FTPClientConfig config2 = config != null ? new FTPClientConfig(config) : null;
return new CompositeFileEntryParser(new FTPFileEntryParser[] { new NTFTPEntryParser(config),
new UnixFTPEntryParser(config2, config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey())) });
}
public FTPFileEntryParser createOS2FTPEntryParser() {
return new OS2FTPEntryParser();
}
public FTPFileEntryParser createOS400FTPEntryParser() {
return createOS400FTPEntryParser(null);
}
/**
* Creates an OS400 FTP parser: if the config exists, and the system key equals {@link FTPClientConfig#SYST_OS400} then a plain {@link OS400FTPEntryParser}
* is used, otherwise a composite of {@link OS400FTPEntryParser} and {@link UnixFTPEntryParser} is used.
*
* @param config the config to use, may be {@code null}
* @return the parser
*/
private FTPFileEntryParser createOS400FTPEntryParser(final FTPClientConfig config) {
if (config != null && FTPClientConfig.SYST_OS400.equals(config.getServerSystemKey())) {
return new OS400FTPEntryParser(config);
}
// clone the config as it may be changed by the parsers (NET-602)
final FTPClientConfig config2 = config != null ? new FTPClientConfig(config) : null;
return new CompositeFileEntryParser(new FTPFileEntryParser[] { new OS400FTPEntryParser(config),
new UnixFTPEntryParser(config2, config2 != null && FTPClientConfig.SYST_UNIX_TRIM_LEADING.equals(config2.getServerSystemKey())) });
}
public FTPFileEntryParser createUnixFTPEntryParser() {
return new UnixFTPEntryParser();
}
public FTPFileEntryParser createVMSVersioningFTPEntryParser() {
return new VMSVersioningFTPEntryParser();
}
}