Java开发网 - 轻松玩转FTP,HTTP,POP3,SMTP,TELNET客户端JAVA程序之FTP篇

Topic: 轻松玩转FTP,HTTP,POP3,SMTP,TELNET客户端JAVA程序之FTP篇

1.轻松玩转FTP,HTTP,POP3,SMTP,TELNET客户端JAVA程序之FTP篇

Posted by: bfcatfriends
Posted on: 2003-08-07 09:17

http://www.jscape.com/可以免费下载inetfactory开发包。
因为本人用过，感觉很好，向大家推荐使用。请多多指教。

下面给出关于FTP的PACKAGE使用说明：

1 Overview
1.1 Introduction
The FTP (File Transfer Protocol) component provides an interface for transmitting data to/from an
FTP server. The FTP component implements standards defined in RFC 959 and RFC 1579.
1.2 Target audience
This document is intended to serve as a technical guide to using the FTP component. Users
should understand the Java™ programming language and be proficient in writing Java™
applications. A basic understanding of FTP and networking protocols is also helpful.
1.3 General features
Ability to upload / download binary and ASCII files
Ability to automatically detect and set data transfer mode
Ability to connect from behind a firewall using a passive FTP connection
Ability to upload / download files using a regular expression
Ability to monitor progress of upload / download using easy to implement event listeners
Ability to upload / download directories recursively

2 Connecting to an FTP server
2.1 Establishing a connection
To establish a connection to an FTP server, create an FTP instance and provide the required
hostname, username and password.
Example:
Ftp ftp = new Ftp("ftp.myserver.com","jsmith","secret");
ftp.connect();
2.2 Setting network connection timeout
You can use the setTimeout method to define the maximum number of milli-seconds to wait
when establishing a connection to an FTP server. Failure to establish a connection within the
maximum time allowed will result in an FtpException.
Example:
ftp.setTimeout(5000);
ftp.connect();
2.3 Connecting from behind a firewall
If you are connecting from behind a firewall you must set the FTP instance to use passive mode
prior to establishing a connection.
Example:
ftp.setPassive(true);
ftp.connect();

3 Capturing FTP related events
3.1 Overview
The FTP component may publish one or more events during the lifetime of an FTP session. Any
object that subscribes to events published by the FTP component can receive and process these
events.
3.2 Listening for events
For an object to listen for events published by the FTP component the following three (3) steps
are required.
1. Set object to implement FtpListener or extend FtpAdapter class.
2. Overload event handling methods.
3. Subscribe object to receive events published by FTP instance.
The FtpListener class is a pure interface and can be used in cases where the class you
defined to listen for events already extends another class type. The FtpAdapter class extends
the FtpListener interface and can be used in cases where there is no need for class
inheritance.
Note: Unless your class requires inheritance it is generally easier to use the FtpAdapter class
as it provides default implementations for all the event handler methods defined in the
FtpListener interface. This allows you to overload only the event handler methods that you
are interested in.
Example 1:
import com.jscape.inet.ftp.*;
public class MyFtpListener implements FtpListener {
public void commandSent(FtpCommandEvent evt) {
// process event
}
public void connected(FtpConnectedEvent evt) {
// process event
}
public void disconnected(FtpDisconnectedEvent evt) {
// process event
}
public void download(FtpDownloadEvent evt) {

// process event
}
public void listing(FtpListingEvent evt) {
// process event
}
public void progress(FtpProgressEvent evt) {
// process event
}
public void responseReceived(FtpResponseEvent evt) {
// process event
}
public void upload(FtpUploadEvent evt) {
// process event
}
public static void main(String[] args) {
try {
Ftp ftp = new Ftp("ftp.myserver.com","jsmith","secret");
// subscribe MyFtpListener to events published
ftp.addFtpListener(new MyFtpListener());
ftp.connect();
ftp.disconnect();
}
catch(Exception e) {
e.printStackTrace();
}
}
}

Example 2:
import com.jscape.inet.ftp.*;
public class MyFtpAdapter extends FtpAdapter {
public void connected(FtpConnectedEvent evt) {
// process event
}
public void disconnected(FtpDisconnectedEvent evt) {
// process event
}
public static void main(String[] args) {
try {
Ftp ftp = new
Ftp("ftp.myserver.com","jsmith","secret");
ftp.addFtpListener(new MyFtpAdapter());
ftp.connect();
ftp.disconnect();
}
catch(Exception e) {
e.printStackTrace();
}
}
}
3.3 FtpConnectedEvent
The FtpConnectedEvent is published by the FTP instance once a connection to the FTP
server has been established. See JavaDoc for details on this event.
3.4 FtpDisconnectedEvent
The FtpDisconnectedEvent is published by the FTP instance once the connection to the FTP
server has been released. See JavaDoc for details on this event.
10
3.5 FtpDownloadEvent
The FtpDownloadEvent is published by the FTP instance for each file downloaded from the
FTP server. See JavaDoc for details on this event.
3.6 FtpListingEvent
The FtpListingEvent is published by the FTP instance for each directory listing retrieved from
the FTP server. See JavaDoc for details on this event.
3.7 FtpProgressEvent
The FtpProgressEvent is published by the FTP instance one or more times during the transfer
of files to / from the FTP server. See JavaDoc for details on this event.
3.8 FtpCommandEvent
The FtpCommandEvent is published by the FTP instance for each command sent to the FTP
server. See JavaDoc for details on this event.
3.9 FtpResponseEvent
The FtpResponseEvent is published by the FTP instance for each response received from the
FTP server. See JavaDoc for details on this event.

4 Setting your directory
4.1 Setting your local directory
Your local directory is the relative path from which all files will be uploaded from or downloaded to
when communicating with an FTP server. If you do not define the local directory the local
directory will default to the directory from which the Java™ VM was instantiated.
ftp.setLocalDir (new File("/usr/home"));
4.2 Setting your remote directory
Your remote directory is the directory on the FTP server from which all files will be uploaded to or
downloaded from when communicating with the FTP server. If you do not define the remote
directory then the remote directory will default to the directory provided upon successful login to
the FTP server.
ftp.setDir("home");

5 Retrieving a directory listing
5.1 Retrieving a remote directory listing
There are two ways that you can retrieve a directory listing from the FTP server. The method
used will depend on the FTP server you are connecting to and how you want to process the
results.
If you want to simply print out the results of a directory listing you may use the
getDirListingAsString method. This returns a String representing the response received
by the FTP server upon requesting a directory listing.
If you are wanting to process the results, evaluating each file returned in the directory listing then
you can use the getDirListing method. This returns an Enumeration of FtpFile. Each
instance of FtpFile contains information such as the filename, filesize, timestamp etc.
Warning: The getDirListing method only works for FTP servers which return a directory
listing in the standard UNIX or MS-DOS formats. For all other formats it is recommended that you
use the getDirListingAsString method.
Example 1:
String results = ftp.getDirListingAsString();
System.out.println(results);
Example 2:
Enumeration files = ftp.getDirListing();
while(files.hasMoreElements()) {
FtpFile file = (FtpFile) files.nextElement();
System.out.println(file.getFilename());
}
5.2 Retrieving a local directory listing
You can retrieve an Enumeration of files from your current local directory. The current local
directory can be set when creating a new FTP instance or by using the setLocalDir method.
See Setting your local directory for details.
Example:
Enumeration files = ftp.getLocalDirListing();
while(files.hasMoreElements()) {
File f = (File) files.nextElement();
System.our.println(f.getName());
}

6 Uploading files
6.1 Automatically detecting the transfer mode
When uploading files the transfer mode is by default set to automatically detect whether to use
ASCII or BINARY transfer mode based on the file extension of the file transferred. If you are
uploading multiple files it is often convenient to have the transfer mode automatically detected
and set based on the type of file being uploaded.
Binary files such as images should be uploaded using the binary transfer mode. ASCII files such
as text documents should be uploaded using the ASCII transfer mode. You can have this
handled automatically using the setAuto method.
Example:
ftp.setAuto(true);
ftp.upload("image.gif");
ftp.upload("file.txt");
6.2 Uploading binary files
To upload binary files you must change the transfer mode to binary. All files will be uploaded from
your current local directory. See Setting your local directory for details.
Example:
ftp.setAuto(false);
ftp.setBinary();
ftp.upload("image.gif");
6.3 Uploading ASCII text files
To upload ASCII text files you must change the transfer mode to ASCII. All files will be uploaded
from your current local directory. See Setting your local directory for details.
Note: The default transfer mode is ASCII text
Example:
ftp.setAuto(false);
ftp.setAscii();
ftp.upload("file.txt");

6.4 Uploading multiple files
You can upload multiple files using the mupload method and a wildcard expression. All files will
be uploaded from your current local directory. See Setting your local directory for details.
Example:
ftp.mupload("*.txt");
6.5 Uploading a directory
You can upload an entire directory using the uploadDir method and a File representing a
directory on your local system.
Example:
File dir = new File("c:/testdir");
ftp.uploadDir(dir);
6.6 Appending files
You can append data to a remote file using any of the Ftp#uploadFile methods that take a second
boolean argument. Rather than replace the remote file, this will append the data that you are
uploading to the remote file.
Example:
File file = new File("c:/tmp/test.txt");
// append file
ftp.uploadFile(file,true);

7 Downloading files
7.1 Automatically detecting the transfer mode
When downloading files the transfer mode is by default set to automatically detect whether to use
ASCII or BINARY transfer mode based on the file extension of the file transferred. If you are
downloading multiple files it is often convenient to have the transfer mode automatically detected.
Binary files such as images should be downloaded using the BINARY transfer mode. ASCII files
such as text documents should be downloaded using the ASCII transfer mode. You can have
this handled automatically using the setAuto method.
Example:
ftp.setAuto(true);
ftp.upload("image.gif");
ftp.upload("file.txt");
7.1 Downloading binary files
To download binary files you must change the transfer mode to binary. All files will be
downloaded relative to your current remote directory. See Setting your remote directory for
details.
Example:
ftp.setAuto(false);
ftp.setBinary();
ftp.download("image.gif");
7.2 Downloading text files
To download ASCII text files you must change the transfer mode to ASCII. All files will be
downloaded relative to your current remote directory. See Setting your remote directory for
details.
Note: The default transfer mode is ASCII text
Example:
ftp.setAuto(false);
ftp.setAscii();
ftp.download("file.txt");

7.3 Downloading multiple files
You can download multiple files using the mdownload method along with a regular expression.
All files will be downloaded relative to your current remote directory. See Setting your remote
directory for details.
Example:
ftp.mdownload("*.txt");
7.4 Downloading a directory
You can download an entire directory using the downloadDir method and a directory name.
Directory to download is relative to your current remote directory. See Setting your remote
directory for details.
Example:
ftp.downloadDir("testdir");

8 Remote file operations
8.1 Creating a remote directory
You can create a remote directory on the FTP server using the makeDir method. The directory
created is relative to your current remote directory. See Setting your remote directory for details.
Example:
ftp.makeDir("testdir");
8.2 Creating a local directory
You can create a local directory using the makeLocalDir method. The directory created is
relative to your current local directory. See Setting your local directory for details.
Example:
ftp.makeLocalDir("testdir");
8.3 Deleting a remote directory
You can delete a remote directory on the FTP server using the deleteDir method. The
directory deleted is relative to your current remote directory. See Setting your remote directory
for details.
Example:
ftp.deleteDir("testdir");
8.4 Renaming a file
You can rename a file using the renameFile method providing the current file name and the
new file name.
Example:
ftp.renameFile("file.txt","newfile.txt");
8.5 Deleting a file
You can delete a file using the deleteFile method.
Example:
ftp.deleteFile("file.txt");

8.6 Retrieving filesize information
You can retrieve the byte size of a file using the getFilesize method.
Note: The getFilesize method utilizes a command that is supported by a majority of FTP
servers however is not officially recognized by RFC 959.
Example:
long bytes = ftp.getFilesize("file.txt");
8.7 Retrieving file timestamp information
You can retrieve the date a file was last modified using the getFileTimestamp method.
Note: The getFileTimestamp method utilizes a command that is supported by a majority of
FTP servers however is not officially recognized by RFC 959.
Example:
Date d = ftp.getFileTimestamp("file.txt");

9 Troubleshooting
9.1 PORT command failure
When attempting to establish a connection to an FTP server you may receive the following error
message.
Example:
500 PORT command failure
The above message indicates that a connection could not be established. This is a common
error for those FTP clients that are behind a firewall. To get around your firewall you may use a
passive FTP connection. To enable a passive FTP connection invoke the Ftp#setPassive
method prior to invoking the Ftp#connect method.
Example:
Ftp ftp = new Ftp(hostname, username, password);
ftp.setPassive(true);
ftp.connect();
9.2 LOGIN incorrect
When attempting to establish a connection to an FTP server you may receive the following error
message:
Example:
530 Login incorrect
The above message indicates that either the username or password is invalid. Check your
username and password to be sure that they are correct.
If you have verified your username and password are correct and you continue to have problems
check the length of your password. Some FTP servers will only accept passwords up to 8
characters in length. If your password is greater than 8 characters in length and you are
experiencing login trouble then try limiting your password to the first 8 characters.
Example:
String username = "jsmith";
String password = "funkyzeit";
String hostname = "10.0.0.2";
Ftp ftp = new Ftp();
ftp.setHostname(hostname);
ftp.setUsername(username);
// limit password to first 8 characters
ftp.setPassword(password.substring(0,8));
// establish connection and login
ftp.connect();

下面在给出实例程序：
/*
* @(#)FtpExample.java
*
* Copyright Coffee

2001-2002 JScape
* 1147 S. 53rd Pl., Mesa, Arizona, 85206, U.S.A.
* All rights reserved.
*
* This software is the confidential and proprietary information of
* JScape. ("Confidential Information"). You shall not disclose such
* Confidential Information and shall use it only in accordance with
* the terms of the license agreement you entered into with JScape.
*/

import com.jscape.inet.ftp.*;
import java.io.*;
import java.util.Enumeration;

public class FtpExample extends FtpAdapter {
private String hostname;
private String username;
private String password;

public FtpExample(String hostname, String username, String password) {
this.hostname = hostname;
this.username = username;
this.password = password;
}

// print out directory listing
public void getListing() throws FtpException {

// create new Ftp instance with hostname, username and password arguments
Ftp ftp = new Ftp(hostname,username,password);

// register this class to capture FTP related events
ftp.addFtpListener(this);

// connect to FTP server
ftp.connect();

// get results of a directory listing
String results = ftp.getDirListingAsString();

// print out directory listing results
System.out.println(results);

// disconnect from FTP server
ftp.disconnect();
}

// captures connect event
public void connected(FtpConnectedEvent evt) {
System.out.println("Connected to server: " + evt.getHostname());
}

// captures disconnect event
public void disconnected(FtpDisconnectedEvent evt) {
System.out.println("Disconnected from server: " + evt.getHostname());
}

public static void main(String[] args) {
String hostname;
String username;
String password;
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter Ftp hostname (e.g. ftp.microsoft.com): ");
hostname = reader.readLine();
System.out.print("Enter username (e.g. anonymous): ");
username = reader.readLine();
System.out.print("Enter password (e.g. user@here.com): ");
password = reader.readLine();
FtpExample example = new FtpExample(hostname,username,password);
example.getListing();
}
catch(Exception e) {
e.printStackTrace();
}
}
}

2.Re [Re: bfcatfriends]	Copy to clipboard
Posted by: jigsaw Posted on: 2003-08-08 16:15 这种文章给个连接就足够了。。。

Topic: 轻松玩转FTP,HTTP,POP3,SMTP,TELNET客户端JAVA程序 之FTP篇

Topic: 轻松玩转FTP,HTTP,POP3,SMTP,TELNET客户端JAVA程序之FTP篇