ftpdownload.java

JAVA FTP客户端经典

import net.sf.jftp.net.ConnectionHandler;
import net.sf.jftp.net.ConnectionListener;
import net.sf.jftp.net.DataConnection;
import net.sf.jftp.net.FtpConnection;
import net.sf.jftp.net.BasicConnection;
import net.sf.jftp.util.Log;
import net.sf.jftp.util.Logger;
import net.sf.jftp.config.Settings;

import java.io.*;

// this class download a file via anonymous ftp and shows output.
//
// if you want to use the api in a more complex way, please do at least take a look at the
// FtpConnection, FtpTransfer, ConnectionHandler, DirPanel (blockedTransfer, transfer)
// and ConnectionListener sourcecode.
public class FtpDownload implements Logger, ConnectionListener
{

 // is the connection established?
 private boolean isThere = false;

 // connection pool, not necessary but you should take a look at this class
 // if you want to use multiple event based ftp transfers.
 private ConnectionHandler handler = new ConnectionHandler();

//creates a FtpConnection and downloads a file
 public FtpDownload(String host, String file)
 {
 	// register app as Logger, debug() and debugRaw below are from now on called by
	// FtpConnection
 	Log.setLogger(this);

	// create a FtpConnection - note that it does *not* connect instantly
 	FtpConnection con = new FtpConnection(host);

	// set updatelistener, interface methods are below
	con.addConnectionListener(this);

	// set handler
	con.setConnectionHandler(handler);

	// connect and login. this is from where connectionFailed() may be called for example
	con.login("anonymous","[e-mail]");

	// login calls connectionInitialized() below which sets isThere to true
	while(!isThere)
	{
		try { Thread.sleep(10); }
		catch(Exception ex) { ex.printStackTrace(); }
	}

	// download the file - this method blocks until the download has finished
	// if you want non-blocking, multithreaded io, just use
	//
	// con.handleDownload(file);
	//
	// which spawns a new thread for the download
	con.download(file);
 }

 // download welcome.msg from sourceforge or any other given file
 public static void main(String argv[])
 {
 	if(argv.length < 2)
	{
		FtpDownload f = new FtpDownload("upload.sourceforge.net", "/welcome.msg");
	}
	else
	{
		FtpDownload f = new FtpDownload(argv[0], argv[1]);
	}
 }

// ------------------ needed by ConnectionListener interface -----------------

// called if the remote directory has changed
 public void updateRemoteDirectory(BasicConnection con)
 {
 	System.out.println("new path is: " + con.getPWD());
 }

 // called if a connection has been established
 public void connectionInitialized(BasicConnection con)
 {
  	isThere = true;
 }
 
 // called every few kb by DataConnection during the trnsfer (interval can be changed in Settings)
 public void updateProgress(String file, String type, long bytes) {}

 // called if connection fails
 public void connectionFailed(BasicConnection con, String why) {System.out.println("connection failed!");}

 // up- or download has finished
 public void actionFinished(BasicConnection con) {}


 // ------------ needed by Logger interface  --------------

    // main log method
    public void debug(String msg) {System.out.println(msg);}

    // rarely used
    public void debugRaw(String msg) {System.out.print(msg);}

    // methods below are not used yet.

    	public void debug(String msg, Throwable throwable) {}

    	public void warn(String msg) {}

    	public void warn(String msg, Throwable throwable) {}

    	public void error(String msg) {}

    	public void error(String msg, Throwable throwable) {}

   	 public void info(String msg) {}

    	public void info(String msg, Throwable throwable) {}

    	public void fatal(String msg) {}

    	public void fatal(String msg, Throwable throwable) {}

}