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.examples.ftp; import java.io.IOException; import java.io.PrintWriter; import java.net.InetAddress; import org.apache.commons.net.PrintCommandListener; import org.apache.commons.net.ProtocolCommandListener; import org.apache.commons.net.ftp.FTPClient; import org.apache.commons.net.ftp.FTPReply; /*** * This is an example program demonstrating how to use the FTPClient class. * This program arranges a server to server file transfer that transfers * a file from host1 to host2. Keep in mind, this program might only work * if host2 is the same as the host you run it on (for security reasons, * some ftp servers only allow PORT commands to be issued with a host * argument equal to the client host). * <p> * Usage: ftp <host1> <user1> <pass1> <file1> <host2> <user2> <pass2> <file2> ***/ public final class ServerToServerFTP { public static void main(String[] args) { String server1, username1, password1, file1; String server2, username2, password2, file2; String[] parts; int port1 = 0, port2 = 0; FTPClient ftp1, ftp2; ProtocolCommandListener listener; if (args.length < 8) { System.err.println("Usage: ftp <host1> <user1> <pass1> <file1> <host2> <user2> <pass2> <file2>"); System.exit(1); } server1 = args[0]; parts = server1.split(":"); if (parts.length == 2) { server1 = parts[0]; port1 = Integer.parseInt(parts[1]); } username1 = args[1]; password1 = args[2]; file1 = args[3]; server2 = args[4]; parts = server2.split(":"); if (parts.length == 2) { server2 = parts[0]; port2 = Integer.parseInt(parts[1]); } username2 = args[5]; password2 = args[6]; file2 = args[7]; listener = new PrintCommandListener(new PrintWriter(System.out), true); ftp1 = new FTPClient(); ftp1.addProtocolCommandListener(listener); ftp2 = new FTPClient(); ftp2.addProtocolCommandListener(listener); try { int reply; if (port1 > 0) { ftp1.connect(server1, port1); } else { ftp1.connect(server1); } System.out.println("Connected to " + server1 + "."); reply = ftp1.getReplyCode(); if (!FTPReply.isPositiveCompletion(reply)) { ftp1.disconnect(); System.err.println("FTP server1 refused connection."); System.exit(1); } } catch (IOException e) { if (ftp1.isConnected()) { try { ftp1.disconnect(); } catch (IOException f) { // do nothing } } System.err.println("Could not connect to server1."); e.printStackTrace(); System.exit(1); } try { int reply; if (port2 > 0) { ftp2.connect(server2, port2); } else { ftp2.connect(server2); } System.out.println("Connected to " + server2 + "."); reply = ftp2.getReplyCode(); if (!FTPReply.isPositiveCompletion(reply)) { ftp2.disconnect(); System.err.println("FTP server2 refused connection."); System.exit(1); } } catch (IOException e) { if (ftp2.isConnected()) { try { ftp2.disconnect(); } catch (IOException f) { // do nothing } } System.err.println("Could not connect to server2."); e.printStackTrace(); System.exit(1); } __main: try { if (!ftp1.login(username1, password1)) { System.err.println("Could not login to " + server1); break __main; } if (!ftp2.login(username2, password2)) { System.err.println("Could not login to " + server2); break __main; } // Let's just assume success for now. ftp2.enterRemotePassiveMode(); ftp1.enterRemoteActiveMode(InetAddress.getByName(ftp2.getPassiveHost()), ftp2.getPassivePort()); // Although you would think the store command should be sent to server2 // first, in reality, ftp servers like wu-ftpd start accepting data // connections right after entering passive mode. Additionally, they // don't even send the positive preliminary reply until after the // transfer is completed (in the case of passive mode transfers). // Therefore, calling store first would hang waiting for a preliminary // reply. if (ftp1.remoteRetrieve(file1) && ftp2.remoteStoreUnique(file2)) { // if(ftp1.remoteRetrieve(file1) && ftp2.remoteStore(file2)) { // We have to fetch the positive completion reply. ftp1.completePendingCommand(); ftp2.completePendingCommand(); } else { System.err.println("Couldn't initiate transfer. Check that file names are valid."); break __main; } } catch (IOException e) { e.printStackTrace(); System.exit(1); } finally { try { if (ftp1.isConnected()) { ftp1.logout(); ftp1.disconnect(); } } catch (IOException e) { // do nothing } try { if (ftp2.isConnected()) { ftp2.logout(); ftp2.disconnect(); } } catch (IOException e) { // do nothing } } } }