ftp 断点上传

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
import java.io.StringWriter;
import java.util.Properties;
import java.util.StringTokenizer;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;

/**
*
* Function Description:FTP 功能类，含put和get方法
*/

public class AppendFtp extends FTPClient {

private Properties envs=getEnvVars();

/*private static org.apache.log4j.Logger logger =
     org.apache.log4j.Logger.getLogger(AppendFtp.class);*/



public void logException(Exception ae){
  StringWriter sw= new StringWriter();
  PrintWriter pw =new PrintWriter(sw);
  ae.printStackTrace(pw);
  //logger.info(sw.getBuffer());
}


  public boolean upload(String remote, String fileName, String local) throws IOException {
     ftp.enterLocalPassiveMode();
//        if(fileName.endsWith(".rar") || fileName.endsWith(".zip") || fileName.endsWith(".jar")) {
         ftp.setFileType(FTPClient.BINARY_FILE_TYPE); //2进制文件时,防止文件损坏
//        }
        boolean result;
       
        ftp.changeWorkingDirectory(remote); //进入ftp目录
        boolean isExists = false;
        long fileSize=123;
        FTPFile[] files = ftp.listFiles();
        for (int i = 0; i < files.length; i++) {
            FTPFile file = files[i];
            System.out.println(fileName+"--fileName-------------file.getName()-"+file.getName());
            if(fileName.equals(file.getName())) {
                isExists = true;
                fileSize=file.getSize();
                break;
            }
        }
        if(isExists) {
            //文件存在时, 使用断点上传方式
            System.out.println("fileSize:" + fileSize);
            File fLocal = new File(local);
            OutputStream os=ftp.appendFileStream(fileName);
            RandomAccessFile randomAccessFileLocal = new RandomAccessFile(fLocal, "r");
            randomAccessFileLocal.seek(fileSize);
            int len = 0;
            byte[] bt = new byte[1024];
            while ((len = randomAccessFileLocal.read(bt)) > 0) {
             os.write(bt, 0, len);
            }
            randomAccessFileLocal.close();
            os.close();
            result = true;
        } else {
         System.out.println("create");
            //不存在时, 直接上传
            File f = new File(local);
            FileInputStream in = new FileInputStream(f);
            result = ftp.storeFile(fileName, in);
            in.close();
        }
        if(fileName.indexOf("ExpDat")>-1){
   boolean deleted=new File(local).delete();
   if(deleted)
    System.out.println("delete file ok!");
   else
    System.out.println("delete not ok!");
  }
        System.out.println("upload ok");
        return result;
    }

    /**
     * 建立FTP连接
     */
    public boolean connect(String hostname, int port, String username,
   String password) throws IOException {
     ftp.connect(hostname, port);
  ftp.login(username, password);
  if (!FTPReply.isPositiveCompletion(ftp.getReplyCode())) {
   disconnect();
   return false;
  }
  return true;
}
   
    /**
     * 关闭FTP连接
     */
    public void disconnect() throws IOException {
  if (ftp.isConnected()) {
   ftp.disconnect();
  }
}
    public FTPClient ftp;
    public void sss(){
     ftp=new FTPClient();
     File fExpDat=new File(envs.getProperty("COMPIERE_HOME")+"/data/ExpDat.jar");
     File fCompiereJar=new File(envs.getProperty("COMPIERE_HOME")+"/lib/Compiere.jar");  
     String ExpDatPath=fExpDat.getPath();
     String CompiereJarPath=fCompiereJar.getPath();
     System.out.println("==ExpDatPath=="+ExpDatPath);
     System.out.println("==CompiereJarPath=="+CompiereJarPath);
     try {
       if(connect("www.zoapcon.com",21,"zoap","zoapfaxftp"))
        System.out.println("login ok!");
       upload("Alison","ExpDat.jar",ExpDatPath);
    upload("Alison","Compiere.jar",CompiereJarPath);
  } catch (IOException e) {
   e.printStackTrace();
  }finally{
   try {
    disconnect();
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
    }
   
  public static void main(String[] args){
   AppendFtp ftpClient = new AppendFtp();
   ftpClient.sss();
  }
 
  public static Properties getEnvVars() {
   Process p = null;
   Properties envVars = new Properties();
   try {
   
    Runtime r = Runtime.getRuntime();
    String OS = System.getProperty("os.name").toLowerCase();
    // System.out.println(OS);
    if (OS.indexOf("windows 9") > -1) {
     p = r.exec("command.com /c set");
    } else if ((OS.indexOf("nt") > -1)
      || (OS.indexOf("windows 20") > -1)
      || (OS.indexOf("windows xp") > -1)) {
     // thanks to JuanFran for the xp fix!
     p = r.exec("cmd.exe /c set");
    } else {
     // our last hope, we assume Unix (thanks to H. Ware for the fix)
     p = r.exec("env");
    }
    BufferedReader br = new BufferedReader(new InputStreamReader(p
      .getInputStream()));
    String line;
    while ((line = br.readLine()) != null) {
     int idx = line.indexOf('=');
     String key = line.substring(0, idx);
     String value = line.substring(idx + 1);
     envVars.setProperty(key, value);
     // System.out.println( key + " = " + value );
    }
   } catch (IOException ioe) {
    ioe.printStackTrace();
   }
   return envVars;
  }
}