Java tutorial
/* Copyright Paul James Mutton, 2001-2004, http://www.jibble.org/ This file is part of SimpleFTP. This software is dual-licensed, allowing you to choose between the GNU General Public License (GPL) and the www.jibble.org Commercial License. Since the GPL may be too restrictive for use in a proprietary application, a commercial license is also provided. Full license information can be found at http://www.jibble.org/licenses/ $Author: pjm2 $ $Id: SimpleFTP.java,v 1.2 2004/05/29 19:27:37 pjm2 Exp $ */ import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.Socket; import java.util.StringTokenizer; /** * SimpleFTP is a simple package that implements a Java FTP client. With * SimpleFTP, you can connect to an FTP server and upload multiple files. * <p> * Copyright Paul Mutton, <a * href="http://www.jibble.org/">http://www.jibble.org/ </a> * */ public class SimpleFTP { /** * Create an instance of SimpleFTP. */ public SimpleFTP() { } /** * Connects to the default port of an FTP server and logs in as * anonymous/anonymous. */ public synchronized void connect(String host) throws IOException { connect(host, 21); } /** * Connects to an FTP server and logs in as anonymous/anonymous. */ public synchronized void connect(String host, int port) throws IOException { connect(host, port, "anonymous", "anonymous"); } /** * Connects to an FTP server and logs in with the supplied username and * password. */ public synchronized void connect(String host, int port, String user, String pass) throws IOException { if (socket != null) { throw new IOException("SimpleFTP is already connected. Disconnect first."); } socket = new Socket(host, port); reader = new BufferedReader(new InputStreamReader(socket.getInputStream())); writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())); String response = readLine(); if (!response.startsWith("220 ")) { throw new IOException( "SimpleFTP received an unknown response when connecting to the FTP server: " + response); } sendLine("USER " + user); response = readLine(); if (!response.startsWith("331 ")) { throw new IOException("SimpleFTP received an unknown response after sending the user: " + response); } sendLine("PASS " + pass); response = readLine(); if (!response.startsWith("230 ")) { throw new IOException("SimpleFTP was unable to log in with the supplied password: " + response); } // Now logged in. } /** * Disconnects from the FTP server. */ public synchronized void disconnect() throws IOException { try { sendLine("QUIT"); } finally { socket = null; } } /** * Returns the working directory of the FTP server it is connected to. */ public synchronized String pwd() throws IOException { sendLine("PWD"); String dir = null; String response = readLine(); if (response.startsWith("257 ")) { int firstQuote = response.indexOf('\"'); int secondQuote = response.indexOf('\"', firstQuote + 1); if (secondQuote > 0) { dir = response.substring(firstQuote + 1, secondQuote); } } return dir; } /** * Changes the working directory (like cd). Returns true if successful. */ public synchronized boolean cwd(String dir) throws IOException { sendLine("CWD " + dir); String response = readLine(); return (response.startsWith("250 ")); } /** * Sends a file to be stored on the FTP server. Returns true if the file * transfer was successful. The file is sent in passive mode to avoid NAT or * firewall problems at the client end. */ public synchronized boolean stor(File file) throws IOException { if (file.isDirectory()) { throw new IOException("SimpleFTP cannot upload a directory."); } String filename = file.getName(); return stor(new FileInputStream(file), filename); } /** * Sends a file to be stored on the FTP server. Returns true if the file * transfer was successful. The file is sent in passive mode to avoid NAT or * firewall problems at the client end. */ public synchronized boolean stor(InputStream inputStream, String filename) throws IOException { BufferedInputStream input = new BufferedInputStream(inputStream); sendLine("PASV"); String response = readLine(); if (!response.startsWith("227 ")) { throw new IOException("SimpleFTP could not request passive mode: " + response); } String ip = null; int port = -1; int opening = response.indexOf('('); int closing = response.indexOf(')', opening + 1); if (closing > 0) { String dataLink = response.substring(opening + 1, closing); StringTokenizer tokenizer = new StringTokenizer(dataLink, ","); try { ip = tokenizer.nextToken() + "." + tokenizer.nextToken() + "." + tokenizer.nextToken() + "." + tokenizer.nextToken(); port = Integer.parseInt(tokenizer.nextToken()) * 256 + Integer.parseInt(tokenizer.nextToken()); } catch (Exception e) { throw new IOException("SimpleFTP received bad data link information: " + response); } } sendLine("STOR " + filename); Socket dataSocket = new Socket(ip, port); response = readLine(); if (!response.startsWith("125 ")) { //if (!response.startsWith("150 ")) { throw new IOException("SimpleFTP was not allowed to send the file: " + response); } BufferedOutputStream output = new BufferedOutputStream(dataSocket.getOutputStream()); byte[] buffer = new byte[4096]; int bytesRead = 0; while ((bytesRead = input.read(buffer)) != -1) { output.write(buffer, 0, bytesRead); } output.flush(); output.close(); input.close(); response = readLine(); return response.startsWith("226 "); } /** * Enter binary mode for sending binary files. */ public synchronized boolean bin() throws IOException { sendLine("TYPE I"); String response = readLine(); return (response.startsWith("200 ")); } /** * Enter ASCII mode for sending text files. This is usually the default mode. * Make sure you use binary mode if you are sending images or other binary * data, as ASCII mode is likely to corrupt them. */ public synchronized boolean ascii() throws IOException { sendLine("TYPE A"); String response = readLine(); return (response.startsWith("200 ")); } /** * Sends a raw command to the FTP server. */ private void sendLine(String line) throws IOException { if (socket == null) { throw new IOException("SimpleFTP is not connected."); } try { writer.write(line + "\r\n"); writer.flush(); if (DEBUG) { System.out.println("> " + line); } } catch (IOException e) { socket = null; throw e; } } private String readLine() throws IOException { String line = reader.readLine(); if (DEBUG) { System.out.println("< " + line); } return line; } private Socket socket = null; private BufferedReader reader = null; private BufferedWriter writer = null; private static boolean DEBUG = false; }