appe.java

用java写的ftp服务器程序

// $Id: APPE.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.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.SocketException;

import org.apache.commons.logging.Log;
import org.apache.ftpserver.Command;
import org.apache.ftpserver.FtpRequestImpl;
import org.apache.ftpserver.FtpWriter;
import org.apache.ftpserver.RequestHandler;
import org.apache.ftpserver.ftplet.FileObject;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.Ftplet;
import org.apache.ftpserver.ftplet.FtpletEnum;
import org.apache.ftpserver.interfaces.IFtpConfig;
import org.apache.ftpserver.interfaces.IFtpStatistics;
import org.apache.ftpserver.util.IoUtils;

/**
 * <code>APPE &lt;SP&gt; &lt;pathname&gt; &lt;CRLF&gt;</code><br>
 *
 * This command causes the server-DTP to accept the data
 * transferred via the data connection and to store the data in
 * a file at the server site.  If the file specified in the
 * pathname exists at the server site, then the data shall be
 * appended to that file; otherwise the file specified in the
 * pathname shall be created at the server site.
 * 
 * @author <a href="mailto:[e-mail]">Rana Bhattacharyya</a>
 */
public 
class APPE implements Command {
    
    /**
     * Execute command.
     */
    public void execute(RequestHandler handler,
                        FtpRequestImpl request, 
                        FtpWriter out) throws IOException, FtpException {
        
        try {
        
            // reset state variables
            request.resetState();
            IFtpConfig fconfig = handler.getConfig();
            
            // argument check
            String fileName = request.getArgument();
            if(fileName == null) {
                out.send(501, "APPE", null);
                return;  
            }
            
            // call Ftplet.onAppendStart() method
            Ftplet ftpletContainer = fconfig.getFtpletContainer();
            FtpletEnum ftpletRet = ftpletContainer.onAppendStart(request, out);
            if(ftpletRet == FtpletEnum.RET_SKIP) {
                return;
            }
            else if(ftpletRet == FtpletEnum.RET_DISCONNECT) {
                fconfig.getConnectionManager().closeConnection(handler);
                return;
            }
            
            // get filenames
            FileObject file = null;
            try {
                file = request.getFileSystemView().getFileObject(fileName);
            }
            catch(Exception ex) {
            }
            if(file == null) {
                out.send(550, "APPE.invalid", fileName);
                return;
            }
            fileName = file.getFullName();
            
            // check file existance
            if( !(file.doesExist() && file.isFile()) ) {
                out.send(550, "APPE.invalid", fileName);
                return;
            }
            
            // check permission
            if( !file.hasWritePermission()) {
                out.send(550, "APPE.permission", fileName);
                return;
            }
            
            // get data connection
            out.send(150, "APPE", fileName);
            InputStream is = null;
            try {
                is = request.getDataInputStream();
            }
            catch(IOException ex) {
                out.send(425, "APPE", fileName);
                return;
            }
             
            // get data from client
            boolean failure = false;
            BufferedInputStream bis = null;
            BufferedOutputStream bos = null;
            try {
                
                // open streams
                bis = IoUtils.getBufferedInputStream(is);
                bos = IoUtils.getBufferedOutputStream( file.createOutputStream(true) );
                    
                // transfer data
                int maxRate = handler.getRequest().getUser().getMaxUploadRate();
                long transSz = handler.transfer(bis, bos, maxRate);
                
                // log message
                String userName = request.getUser().getName();
                Log log = fconfig.getLogFactory().getInstance(getClass());
                log.info("File upload : " + userName + " - " + fileName);
                
                // notify the statistics component
                IFtpStatistics ftpStat = (IFtpStatistics)fconfig.getFtpStatistics();
                ftpStat.setUpload(handler, file, transSz);
            }
            catch(SocketException ex) {
                failure = true;
                out.send(426, "APPE", fileName);
            }
            catch(IOException ex) {
                failure = true;
                out.send(551, "APPE", fileName);
            }
            finally {
                IoUtils.close(bis);
                IoUtils.close(bos);
            }
            
            // if data transfer ok - send transfer complete message
            if(!failure) {
                out.send(226, "STOR", fileName);
                
                // call Ftplet.onAppendEnd() method
                ftpletRet = ftpletContainer.onAppendEnd(request, out);
                if(ftpletRet == FtpletEnum.RET_DISCONNECT) {
                    fconfig.getConnectionManager().closeConnection(handler);
                    return;
                }
            }
        }
        finally {
            request.getFtpDataConnection().closeDataSocket();
        }
    }
}