/*
* 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.ftpserver.command;
import java.io.IOException;
import org.apache.ftpserver.ftplet.FtpReply;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.interfaces.FtpIoSession;
import org.apache.ftpserver.interfaces.FtpServerContext;
import org.apache.ftpserver.interfaces.MessageResource;
import org.apache.ftpserver.util.FtpReplyUtil;
/**
* <code>HELP [<SP> <string>] <CRLF></code><br>
*
* This command shall cause the server to send helpful
* information regarding its implementation status over the
* control connection to the user. The command may take an
* argument (e.g., any command name) and return more specific
* information as a response.
*/
public
class HELP extends AbstractCommand {
/**
* Execute command.
*/
public void execute(final FtpIoSession session,
final FtpServerContext context,
final FtpRequest request) throws IOException {
// reset state variables
session.resetState();
// print global help
if(!request.hasArgument()) {
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_214_HELP_MESSAGE, null, null));
return;
}
// print command specific help if available
String ftpCmd = request.getArgument().toUpperCase();
MessageResource resource = context.getMessageResource();
if(resource.getMessage(FtpReply.REPLY_214_HELP_MESSAGE, ftpCmd, session.getLanguage()) == null) {
ftpCmd = null;
}
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_214_HELP_MESSAGE, ftpCmd, null));
}
}