利用org.apache.commons.net.ftp包实现一个简单的ftp客户端实用类。主要实现一下功能
1.支持上传下载。支持断点续传
2.支持进度汇报
3.支持对于中文目录及中文文件创建的支持。
import
java.io.File;
import
java.io.FileOutputStream;
import
java.io.IOException;
import
java.io.InputStream;
import
java.io.OutputStream;
import
java.io.PrintWriter;
import
java.io.RandomAccessFile;
import
open.mis.data.DownloadStatus;
import
open.mis.data.UploadStatus;
import
org.apache.commons.net.PrintCommandListener;
import
org.apache.commons.net.ftp.FTP;
import
org.apache.commons.net.ftp.FTPClient;
import
org.apache.commons.net.ftp.FTPFile;
import
org.apache.commons.net.ftp.FTPReply;

/** */
/**
* 支持断点续传的FTP实用类
* @author BenZhou http://www.bt285.cn
* @version 0.1 实现基本断点上传下载
* @version 0.2 实现上传下载进度汇报
* @version 0.3 实现中文目录创建及中文文件创建,添加对于中文的支持
*/

public
class
ContinueFTP
{
public FTPClient ftpClient = new FTPClient();

public ContinueFTP()
{
// 设置将过程中使用到的命令输出到控制台
this .ftpClient.addProtocolCommandListener( new PrintCommandListener( new PrintWriter(System.out)));
}

/** */ /**
* 连接到FTP服务器
* @param hostname 主机名
* @param port 端口
* @param username 用户名
* @param password 密码
* @return 是否连接成功
* @throws IOException
*/

public boolean connect(String hostname, int port,String username,String password) throws IOException
{
ftpClient.connect(hostname, port);
ftpClient.setControlEncoding( " GBK " );

if (FTPReply.isPositiveCompletion(ftpClient.getReplyCode()))
{

if (ftpClient.login(username, password))
{
return true ;
}
}
disconnect();
return false ;
}

/** */ /**
* 从FTP服务器上下载文件,支持断点续传,上传百分比汇报
* @param remote 远程文件路径
* @param local 本地文件路径
* @return 上传的状态
* @throws IOException
*/

public DownloadStatus download(String remote,String local) throws IOException
{
// 设置被动模式
ftpClient.enterLocalPassiveMode();
// 设置以二进制方式传输
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
DownloadStatus result;
// 检查远程文件是否存在
FTPFile[] files = ftpClient.listFiles( new String(remote.getBytes( " GBK " ), " iso-8859-1 " ));

if (files.length != 1 )
{
System.out.println( " 远程文件不存在 " );
return DownloadStatus.Remote_File_Noexist;
}
long lRemoteSize = files[ 0 ].getSize();
File f = new File(local);
// 本地存在文件,进行断点下载

if (f.exists())
{
long localSize = f.length();
// 判断本地文件大小是否大于远程文件大小

if (localSize >= lRemoteSize)
{
System.out.println( " 本地文件大于远程文件,下载中止 " );
return DownloadStatus.Local_Bigger_Remote;
}
// 进行断点续传,并记录状态
FileOutputStream out = new FileOutputStream(f, true );
ftpClient.setRestartOffset(localSize);
InputStream in = ftpClient.retrieveFileStream( new String(remote.getBytes( " GBK " ), " iso-8859-1 " ));
byte [] bytes = new byte [ 1024 ];
long step = lRemoteSize / 100 ;
long process = localSize / step;
int c;

while ((c = in.read(bytes)) != - 1 )
{
out.write(bytes, 0 ,c);
localSize += c;
long nowProcess = localSize / step;

if (nowProcess > process)
{
process = nowProcess;
if (process % 10 == 0 )
System.out.println( " 下载进度: " + process);
// TODO 更新文件下载进度,值存放在process变量中
}
}
in.close();
out.close();
boolean isDo = ftpClient.completePendingCommand();

if (isDo)
{
result = DownloadStatus.Download_From_Break_Success;

} else
{
result = DownloadStatus.Download_From_Break_Failed;
}

} else
{
OutputStream out = new FileOutputStream(f);
InputStream in = ftpClient.retrieveFileStream( new String(remote.getBytes( " GBK " ), " iso-8859-1 " ));
byte [] bytes = new byte [ 1024 ];
long step = lRemoteSize / 100 ;
long process = 0 ;
long localSize = 0L ;
int c;

while ((c = in.read(bytes)) != - 1 )
{
out.write(bytes, 0 , c);
localSize += c;
long nowProcess = localSize / step;

if (nowProcess > process)
{
process = nowProcess;
if (process % 10 == 0 )
System.out.println( " 下载进度: " + process);
// TODO 更新文件下载进度,值存放在process变量中
}
}
in.close();
out.close();
boolean upNewStatus = ftpClient.completePendingCommand();

if (upNewStatus)
{
result = DownloadStatus.Download_New_Success;

} else
{
result = DownloadStatus.Download_New_Failed;
}
}
return result;
}

/** */ /**
* 上传文件到FTP服务器,支持断点续传
* @param local 本地文件名称,绝对路径
* @param remote 远程文件路径,使用/home/directory1/subdirectory/file.ext或是 http://www.guihua.org /subdirectory/file.ext 按照Linux上的路径指定方式,支持多级目录嵌套,支持递归创建不存在的目录结构
* @return 上传结果
* @throws IOException
*/

public UploadStatus upload(String local,String remote) throws IOException
{
// 设置PassiveMode传输
ftpClient.enterLocalPassiveMode();
// 设置以二进制流的方式传输
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
ftpClient.setControlEncoding( " GBK " );
UploadStatus result;
// 对远程目录的处理
String remoteFileName = remote;

if (remote.contains( " / " ))
{
remoteFileName = remote.substring(remote.lastIndexOf( " / " ) + 1 );
// 创建服务器远程目录结构,创建失败直接返回

if (CreateDirecroty(remote, ftpClient) == UploadStatus.Create_Directory_Fail)
{
return UploadStatus.Create_Directory_Fail;
}
}
// 检查远程是否存在文件
FTPFile[] files = ftpClient.listFiles( new String(remoteFileName.getBytes( " GBK " ), " iso-8859-1 " ));

if (files.length == 1 )
{
long remoteSize = files[ 0 ].getSize();
File f = new File(local);
long localSize = f.length();

if (remoteSize == localSize)
{
return UploadStatus.File_Exits;

} else if (remoteSize > localSize)
{
return UploadStatus.Remote_Bigger_Local;
}
// 尝试移动文件内读取指针,实现断点续传
result = uploadFile(remoteFileName, f, ftpClient, remoteSize);
// 如果断点续传没有成功,则删除服务器上文件,重新上传

if (result == UploadStatus.Upload_From_Break_Failed)
{

if ( ! ftpClient.deleteFile(remoteFile