rest.java

来自「用java写的ftp服务器程序」· Java 代码 · 共 78 行

// $Id: REST.java 306757 2005-10-06 11:33:33 +0530 (Thu, 06 Oct 2005) rana_b $
/*
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed 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.Command;
import org.apache.ftpserver.FtpRequestImpl;
import org.apache.ftpserver.FtpWriter;
import org.apache.ftpserver.RequestHandler;

/**
 * <code>REST &lt;SP&gt; <marker> &lt;CRLF&gt;</code><br>
 *
 * The argument field represents the server marker at which
 * file transfer is to be restarted.  This command does not
 * cause file transfer but skips over the file to the specified
 * data checkpoint.  This command shall be immediately followed
 * by the appropriate FTP service command which shall cause
 * file transfer to resume.
 * 
 * @author <a href="mailto:[e-mail]">Rana Bhattacharyya</a>
 */
public 
class REST implements Command {

    /**
     * Execute command
     */
    public void execute(RequestHandler handler, 
                        FtpRequestImpl request, 
                        FtpWriter out) throws IOException {
        
        // argument check
        String argument = request.getArgument();
        if(argument == null) {
            out.send(501, "REST", null);
            return;  
        }
        
        // get offset number
        request.resetState();
        long skipLen = 0L;
        try {
            skipLen = Long.parseLong(argument);
            
            // check offset number
            if(skipLen < 0L) {
                skipLen = 0L;
                out.send(501, "REST.negetive", null);
            }
            else {
                out.send(350, "REST", null);
            }
        }
        catch(NumberFormatException ex) {
            out.send(501, "REST.invalid", null); 
        }
        
        request.setFileOffset(skipLen);
    } 
    
}