这是偶第一次写java程序实现公司要求的FTP数据同步，所有原代码如下，以供各位参考并提出宝贵意见！另外俺还有两个功能没有实现，有请高手指点一二：1、如何删除FTP服务器上已经下载过的文件？2、如何将上传的文件改名？上传时在文件名前加“temp_”，上传完毕后需要把文件名改回来。3、如何使用openPassiveDataConnection()方法将ftp连接更改为主动连接，因为要从unix系统配置的ftp服务器下载文件的话，就需要主动连接。



/*
*******************************************************************************************************

Filename:  ftp.java
Author:   leetsing(elove)
Create date: 2004-08-30
Use:   connect to FTP server,then upload and download file
Modify date: 2004-09-05 add to upload file
     2004-09-13 add to download file
Copy right:  Magisky Media Technology Co.,Ltd.

*******************************************************************************************************
*/
//import cz.dhl.io.*;
//import cz.dhl.ftp.*;
import sun.net.ftp.*;
import sun.net.*;
import java.applet.*;
import java.io.*;
import java.io.IOException;
import java.util.StringTokenizer;
import sun.net.ftp.FtpClient;
import java.util.ArrayList;

public class ftp  extends Applet
{
FtpClient aftp;
DataOutputStream outputs ;
TelnetInputStream ins;
TelnetOutputStream outs;

int ch;
public String a;
String hostname="";
private String path = "/";

public static void main(String[] args)
{
  String hostname = "192.168.0.56";
  int port = 2121;
  String uid = "lee";
  String pwd = "lee";
  String RWFileDir = "D:\\smsftp\\";//文件目录

  //连接ftp服务器
  ftp ft = new  ftp();
  ft.connect(RWFileDir,hostname,port,uid,pwd);

  //下载文件
  if (ft.aftp != null){
   try {
    ft.getNameList(RWFileDir);
   }catch(IOException e)
   {
    System.out.println("下载文件出错："+e);
   }
  }


  //上传文件
  if (ft.aftp != null){
   String sdir = RWFileDir + "subunsubfromsp\\";
   File fdir = new File(sdir);
   String FileName = "";
  
   for(int i=0;i    FileName = sdir + (fdir.list())[i];
   
    ft.uploadFile(RWFileDir,FileName);
   }
   //System.out.println("成功上传的文件：");
   //ft.showFileContents("subunsubfromsp\\");
  }

  //删除subunsubfromsp目录下已经上传的文件文件
//  ft.deleFile(RWFileDir);

  //断开服务器连接
  ft.stop(RWFileDir);

}

public FtpClient connect(String RWFileDir,String hostname,int port,String uid,String pwd)
{
  this.hostname = hostname;
  System.out.println("正在连接"+hostname+"，请等待.....");
  try{
   aftp = new FtpClient(hostname,port);
   aftp.login(uid,pwd);
   aftp.binary();
   //aftp.openPortDataConnection();
   a = "连接主机:"+hostname+"成功!";
   System.out.println(a);
  }
  catch(FtpLoginException e){
   a="登陆主机:"+hostname+"失败!请检查用户名或密码是否正确："+e;
   System.out.println(a);
   //return false;
  }
  catch (IOException e){
   a="连接主机:"+hostname+"失败!请检查端口是否正确："+e;
   System.out.println(a);
   //return false;
  }
  catch(SecurityException e)
  {
   a="无权限与主机:"+hostname+"连接!请检查是否有访问权限："+e;
   System.out.println(a);
   //return false;
  }
  
  log(RWFileDir,a);
  return aftp;
}

public void stop(String RWFileDir)
{
  String message = "";
  try {
   if(aftp!=null){
    aftp.closeServer();
    message = "与主机"+hostname+"连接已断开!";
    System.out.println(message);
    log(RWFileDir,message);
   }
  }
  catch(IOException e)
  {
   message = "与主机"+hostname+"断开连接失败!"+e;
   System.out.println(message);
   log(RWFileDir,message);
  }
}


public boolean downloadFile(String RWFileDir,String filepathname){
  boolean result=true;
  String message = "";
  if (aftp != null)
  {
   System.out.println("正在下载文件"+filepathname+",请等待....");
   String badfile = filepathname.substring(filepathname.length()-4,filepathname.length());
   String badlog = filepathname.substring(filepathname.length()-7,filepathname.length());
   String baddir = "";
   if ((badfile.compareTo(".bad") != 0) && (badlog.compareTo(".badlog") != 0)){
    baddir = "subunsubtosp\\";
   }
   else{
    baddir = "bad\\";
   }
   String strdir = "subunsubtosp\\";
   //System.out.println(RWFileDir + baddir + filepathname);
   try{
    //FtpClient fc=new FtpClient("192.168.0.56",2121);
    //fc.login("lee","lee");
    int ch;
    File fi = new File(RWFileDir + baddir + filepathname);
    //aftp.cd(strdir);
    RandomAccessFile getFile = new RandomAccessFile(fi,"rw");
    getFile.seek(0);
    TelnetInputStream fget=aftp.get(strdir+filepathname);
    DataInputStream puts = new DataInputStream(fget);
    while ((ch = puts.read()) >= 0) {
     getFile.write(ch);
     
    }
    //s.delete();
    
    fget.close();
    getFile.close();
    //fc.closeServer();

    message = "下载"+filepathname+"文件到"+baddir +"目录成功!";
    System.out.println(message);
    log(RWFileDir,message);
   }
   catch(IOException e){
    message = "下载"+filepathname+"文件到"+baddir +"目录失败!"+e;
    System.out.println(message);
    log(RWFileDir,message);
    result = false ;

   }
  }
  else{
   result = false;
  }
  return result;
}


public boolean uploadFile(String RWFileDir,String filepathname){
  boolean result=true;
  String message = "";
  if (aftp != null)
  {
   System.out.println("正在上传文件"+filepathname+",请等待....");

   try{
    String fg =new  String("\\subunsubfromsp\\");
    int index = filepathname.lastIndexOf(fg);
    String filename = filepathname.substring(index+1);
    File localFile = new File(filepathname) ;
      
    RandomAccessFile sendFile = new RandomAccessFile(filepathname,"r");
    //
    sendFile.seek(0);
    //改名上传temp_
    filename = filename.substring(0,15)+"temp_"+filename.substring(15,filename.length());
    outs = aftp.put(filename);
    outputs = new DataOutputStream(outs);
    while (sendFile.getFilePointer() < sendFile.length() )
    {
     ch = sendFile.read();
     outputs.write(ch);
    }
    
    rename(filename.substring(15,filename.length()),filename.substring(20,filename.length()));
    outs.close();
    sendFile.close();
    
    message = "上传"+filepathname+"文件成功!";
    System.out.println(message);
    log(RWFileDir,message);
   }
   catch(IOException e){
    message = "上传"+filepathname+"文件失败!"+e;
    System.out.println(message);
    log(RWFileDir,message);
    result = false ;

   }
  }
  else{
   result = false;
  }
  return result;
}

public void rename(String oldName,String newName){
  
   //aftp.renameTo(oldName,newName);
   File Old = new File(oldName); //oldName
   File New = new File(newName); //newName
   //aftp.renameTo(New);
   //boolean Old.renameTo(File newName);
   //System.out.println(Old);
   //System.out.println(New);
  
}

public static void deleFile(String RWFileDir) {
//try {
  //取得ReadFile目录下的txt文件
  String sdir = RWFileDir + "subunsubfromsp\\";
  File fdir = new File(sdir);
  String FileName = "";
  int j = fdir.list().length;
  
  System.out.println(sdir+"目录下要删除的文件数："+fdir.list().length);
  File  file;
  for(int i=0;i  {
   //删除subunsubfromsp中的txt文件
   FileName = RWFileDir + "subunsubfromsp\\" + (fdir.list())[0];
   file = new  File(FileName);
   file.delete();
   System.out.println("已经成功删除"+FileName+"文件！");
  }
//}
//catch (IOException e) {
// System.out.println("删除txt文件错误!");
// e.printStackTrace();
//}
}


public void showFileContents(String strdir)
{
  StringBuffer buf = new StringBuffer();
  try {
   aftp.cd(strdir);
   ins= aftp.list();
   while ((ch=ins.read())>=0){
    buf.append((char)ch);
   }
   
   System.out.println(buf.toString());

   ins.close();
        }
  catch(IOException e)
  {
  }
}



// 返回当前目录的所有文件及文件夹

public ArrayList getFileList() throws IOException {
  BufferedReader dr = new BufferedReader(new InputStreamReader(aftp.list()));
  ArrayList al = new ArrayList();
  String s = "";
  while ( (s = dr.readLine()) != null) {
  al.add(s);
  }
  return al;
}

public void setPath(String path) throws IOException {
  if (aftp == null)
  this.path = path;
  else {
   aftp.cd(path);
  }
}

// 返回当前目录的文件名称

public ArrayList getNameList(String RWFileDir) throws IOException {
  
  BufferedReader dr = new BufferedReader(new InputStreamReader(aftp.nameList("subunsubtosp\\")));
  ArrayList al = new ArrayList();
  String s = "";
  while ( (s = dr.readLine()) != null) {
   al.add(s);
   s = s.substring(13,s.length());
   isFile(s);
   downloadFile(RWFileDir,s);
   //String strFileDelF = aftp.nameList("subunsubtosp\\");
   File fileDelF=new File(s);
   fileDelF.delete();
  }
  return al;
  //System.out.println(al.add(s));
}

// 判断一行文件信息是否为目录

public boolean isDir(String line) {
  return ( (String) parseLine(line).get(0)).indexOf("d") != -1;
}

public boolean isFile(String line) {
  return!isDir(line);
}

// 处理getFileList取得的行信息

private ArrayList parseLine(String line) {
  ArrayList s1 = new ArrayList();
  StringTokenizer st = new StringTokenizer(line, " ");
  while (st.hasMoreTokens()) {
   s1.add(st.nextToken());
  }
   return s1;
}

//写消息日志
public static void log(String RWFileDir,String msg)
{
  String message = "";
  try {
   java.text.DateFormat df = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   java.text.DateFormat dflog = new java.text.SimpleDateFormat("yyyyMMdd");
   java.util.Date date = new java.util.Date() ;
   String datestr = df.format(new java.util.Date()) ;
   String datelog = dflog.format(new java.util.Date()) ;
   //String datelog = datestr.substring(0,10);
   //datelog = datelog.replace('-',' ');

   //按日期每天生成一个日志文件
   FileWriter fwl = new FileWriter(RWFileDir + "CMSSftp"+datelog+".log",true);
   PrintWriter outl = new PrintWriter(fwl);
   outl.println(datestr + "  " + msg);
   outl.close();
   fwl.close();
  }catch (IOException e) {
   message = "写log文件错误!"+e;
   e.printStackTrace();
   log(RWFileDir,message);
   System.out.println(message);
  }
}
}