ftpclientlinux下載文件

A. linux環境下使用FTPClient.retrieveFile()下載文件卡死、求教。。。問題解決後再加200分

樓主，每一步多加些調試猛物毀的語枝備句，方便測試到問螞遲題。。。。。。

B. java 實現ftp上傳下載，windows下和linux下游何區別

packagecom.weixin.util;

importjava.io.File;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.OutputStream;
importjava.io.PrintWriter;
importjava.io.RandomAccessFile;

importorg.apache.commons.net.PrintCommandListener;
importorg.apache.commons.net.ftp.FTP;
importorg.apache.commons.net.ftp.FTPClient;
importorg.apache.commons.net.ftp.FTPFile;
importorg.apache.commons.net.ftp.FTPReply;

importcom.weixin.constant.DownloadStatus;
importcom.weixin.constant.UploadStatus;

/**
*支持斷點續傳的FTP實用類
*@version0.1實現基本斷點上傳下載
*@version0.2實現上傳下載進度匯報
*@version0.3實現中文目錄創建及中文文件創建，添加對於中文的支持
*/
publicclassContinueFTP{
	publicFTPClientftpClient=newFTPClient();
	
	publicContinueFTP(){
		//設置將過程中使用到的命令輸出到控制台
		this.ftpClient.addProtocolCommandListener(newPrintCommandListener(newPrintWriter(System.out)));
	}
	
	/**
	*連接到FTP伺服器
	*@paramhostname主機名
	*@paramport埠
	*@paramusername用戶名
	*@parampassword密碼
	*@return是否連接成功
	*@throwsIOException
	*/
	publicbooleanconnect(Stringhostname,intport,Stringusername,Stringpassword)throwsIOException{
		ftpClient.connect(hostname,port);
		ftpClient.setControlEncoding("GBK");
		if(FTPReply.isPositiveCompletion(ftpClient.getReplyCode())){
			if(ftpClient.login(username,password)){
				returntrue;
			}
		}
		disconnect();
		returnfalse;
	}
	
	/**
	*從FTP伺服器上下載文件,支持斷點續傳，上傳百分比匯報
	*@paramremote遠程文件路徑
	*@paramlocal本地文件路徑
	*@return上傳的狀態
	*@throwsIOException
	*/
	publicDownloadStatusdownload(Stringremote,Stringlocal)throwsIOException{
		//設置被動模式
		ftpClient.enterLocalPassiveMode();
		//設置以二進制方式傳輸
		ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
		DownloadStatusresult;
		
		//檢查遠程文件是否存在
		FTPFile[]files=ftpClient.listFiles(newString(remote.getBytes("GBK"),"iso-8859-1"));
		if(files.length!=1){
			System.out.println("遠程文件不存在");
			returnDownloadStatus.Remote_File_Noexist;
		}
		
		longlRemoteSize=files[0].getSize();
		Filef=newFile(local);
		//本地存在文件，進行斷點下載
		if(f.exists()){
			longlocalSize=f.length();
			//判斷本地文件大小是否大於遠程文件大小
			if(localSize>=lRemoteSize){
				System.out.println("本地文件大於遠程文件，下載中止");
				returnDownloadStatus.Local_Bigger_Remote;
			}
			
			//進行斷點續傳，並記錄狀態
			FileOutputStreamout=newFileOutputStream(f,true);
			ftpClient.setRestartOffset(localSize);
			InputStreamin=ftpClient.retrieveFileStream(newString(remote.getBytes("GBK"),"iso-8859-1"));
			byte[]bytes=newbyte[1024];
			longstep=lRemoteSize/100;
			longprocess=localSize/step;
			intc;
			while((c=in.read(bytes))!=-1){
				out.write(bytes,0,c);
				localSize+=c;
				longnowProcess=localSize/step;
				if(nowProcess>process){
					process=nowProcess;
					if(process%10==0)
						System.out.println("下載進度："+process);
					//TODO更新文件下載進度,值存放在process變數中
				}
			}
			in.close();
			out.close();
			booleanisDo=ftpClient.completePendingCommand();
			if(isDo){
				result=DownloadStatus.Download_From_Break_Success;
			}else{
				result=DownloadStatus.Download_From_Break_Failed;
			}
		}else{
			OutputStreamout=newFileOutputStream(f);
			InputStreamin=ftpClient.retrieveFileStream(newString(remote.getBytes("GBK"),"iso-8859-1"));
			byte[]bytes=newbyte[1024];
			longstep=lRemoteSize/100;
			longprocess=0;
			longlocalSize=0L;
			intc;
			while((c=in.read(bytes))!=-1){
				out.write(bytes,0,c);
				localSize+=c;
				longnowProcess=localSize/step;
				if(nowProcess>process){
					process=nowProcess;
					if(process%10==0)
						System.out.println("下載進度："+process);
					//TODO更新文件下載進度,值存放在process變數中
				}
			}
			in.close();
			out.close();
			booleanupNewStatus=ftpClient.completePendingCommand();
			if(upNewStatus){
				result=DownloadStatus.Download_New_Success;
			}else{
				result=DownloadStatus.Download_New_Failed;
			}
		}
		returnresult;
	}
	
	/**
	*上傳文件到FTP伺服器，支持斷點續傳
	*@paramlocal本地文件名稱，絕對路徑
	*@paramremote遠程文件路徑，使用/home/directory1/subdirectory/file.ext按照Linux上的路徑指定方式，支持多級目錄嵌套，支持遞歸創建不存在的目錄結構
	*@return上傳結果
	*@throwsIOException
	*/
	publicUploadStatusupload(Stringlocal,Stringremote)throwsIOException{
		//設置PassiveMode傳輸
		ftpClient.enterLocalPassiveMode();
		//設置以二進制流的方式傳輸
		ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
		ftpClient.setControlEncoding("GBK");
		UploadStatusresult;
		//對遠程目錄的處理
		StringremoteFileName=remote;
		if(remote.contains("/")){
			remoteFileName=remote.substring(remote.lastIndexOf("/")+1);
			//創建伺服器遠程目錄結構，創建失敗直接返回
			if(CreateDirecroty(remote,ftpClient)==UploadStatus.Create_Directory_Fail){
				returnUploadStatus.Create_Directory_Fail;
			}
		}
		
		//檢查遠程是否存在文件
		FTPFile[]files=ftpClient.listFiles(newString(remoteFileName.getBytes("GBK"),"iso-8859-1"));
		if(files.length==1){
			longremoteSize=files[0].getSize();
			Filef=newFile(local);
			longlocalSize=f.length();
			if(remoteSize==localSize){
				returnUploadStatus.File_Exits;
			}elseif(remoteSize>localSize){
				returnUploadStatus.Remote_Bigger_Local;
			}
			
			//嘗試移動文件內讀取指針,實現斷點續傳
			result=uploadFile(remoteFileName,f,ftpClient,remoteSize);
			
			//如果斷點續傳沒有成功，則刪除伺服器上文件，重新上傳
			if(result==UploadStatus.Upload_From_Break_Failed){
				if(!ftpClient.deleteFile(remoteFileName)){
					returnUploadStatus.Delete_Remote_Faild;
				}
				result=uploadFile(remoteFileName,f,ftpClient,0);
			}
		}else{
			result=uploadFile(remoteFileName,newFile(local),ftpClient,0);
		}
		returnresult;
	}
	/**
	*斷開與遠程伺服器的連接
	*@throwsIOException
	*/
	publicvoiddisconnect()throwsIOException{
		if(ftpClient.isConnected()){
			ftpClient.disconnect();
		}
	}
	
	/**
	*遞歸創建遠程伺服器目錄
	*@paramremote遠程伺服器文件絕對路徑
	*@paramftpClientFTPClient對象
	*@return目錄創建是否成功
	*@throwsIOException
	*/
	(Stringremote,FTPClientftpClient)throwsIOException{
		UploadStatusstatus=UploadStatus.Create_Directory_Success;
		Stringdirectory=remote.substring(0,remote.lastIndexOf("/")+1);
		if(!directory.equalsIgnoreCase("/")&&!ftpClient.changeWorkingDirectory(newString(directory.getBytes("GBK"),"iso-8859-1"))){
			//如果遠程目錄不存在，則遞歸創建遠程伺服器目錄
			intstart=0;
			intend=0;
			if(directory.startsWith("/")){
				start=1;
			}else{
				start=0;
			}
			end=directory.indexOf("/",start);
			while(true){
				StringsubDirectory=newString(remote.substring(start,end).getBytes("GBK"),"iso-8859-1");
				if(!ftpClient.changeWorkingDirectory(subDirectory)){
					if(ftpClient.makeDirectory(subDirectory)){
						ftpClient.changeWorkingDirectory(subDirectory);
					}else{
						System.out.println("創建目錄失敗");
						returnUploadStatus.Create_Directory_Fail;
					}
				}
				
				start=end+1;
				end=directory.indexOf("/",start);
				
				//檢查所有目錄是否創建完畢
				if(end<=start){
					break;
				}
			}
		}
		returnstatus;
	}
	
	/**
	*上傳文件到伺服器,新上傳和斷點續傳
	*@paramremoteFile遠程文件名，在上傳之前已經將伺服器工作目錄做了改變
	*@paramlocalFile本地文件File句柄，絕對路徑
	*@paramprocessStep需要顯示的處理進度步進值
	*@paramftpClientFTPClient引用
	*@return
	*@throwsIOException
	*/
	publicUploadStatusuploadFile(StringremoteFile,FilelocalFile,FTPClientftpClient,longremoteSize)throwsIOException{
		UploadStatusstatus;
		//顯示進度的上傳
		longstep=localFile.length()/100;
		longprocess=0;
		longlocalreadbytes=0L;
		RandomAccessFileraf=newRandomAccessFile(localFile,"r");
		OutputStreamout=ftpClient.appendFileStream(newString(remoteFile.getBytes("GBK"),"iso-8859-1"));
		//斷點續傳
		if(remoteSize>0){
			ftpClient.setRestartOffset(remoteSize);
			process=remoteSize/step;
			raf.seek(remoteSize);
			localreadbytes=remoteSize;
		}
		byte[]bytes=newbyte[1024];
		intc;
		while((c=raf.read(bytes))!=-1){
			out.write(bytes,0,c);
			localreadbytes+=c;
			if(localreadbytes/step!=process){
				process=localreadbytes/step;
				System.out.println("上傳進度:"+process);
				//TODO匯報上傳狀態
			}
		}
		out.flush();
		raf.close();
		out.close();
		booleanresult=ftpClient.completePendingCommand();
		if(remoteSize>0){
			status=result?UploadStatus.Upload_From_Break_Success:UploadStatus.Upload_From_Break_Failed;
		}else{
			status=result?UploadStatus.Upload_New_File_Success:UploadStatus.Upload_New_File_Failed;
		}
		returnstatus;
	}
	
	publicstaticvoidmain(String[]args){
		ContinueFTPmyFtp=newContinueFTP();
		try{
			System.err.println(myFtp.connect("10.10.6.236",21,"5","jieyan"));
//			myFtp.ftpClient.makeDirectory(newString("歌曲".getBytes("GBK"),"iso-8859-1"));
//			myFtp.ftpClient.changeWorkingDirectory(newString("歌曲".getBytes("GBK"),"iso-8859-1"));
//			myFtp.ftpClient.makeDirectory(newString("愛你等於愛自己".getBytes("GBK"),"iso-8859-1"));
//			System.out.println(myFtp.upload("E:\yw.flv","/yw.flv",5));
//			System.out.println(myFtp.upload("E:\愛你等於愛自己.mp4","/愛你等於愛自己.mp4"));
			//System.out.println(myFtp.download("/愛你等於愛自己.mp4","E:\愛你等於愛自己.mp4"));
			myFtp.disconnect();
		}catch(IOExceptione){
			System.out.println("連接FTP出錯："+e.getMessage());
		}
	}
}

C. linux下java實現ftp下載，ftpClient.listFiles();返回的數組長度一直是0

試過remote 被動模式嗎。 因為環境的不同，別人難測試到同樣的情形

D. java中在linux環境下，運用org.apache.commons.net.ftp.FTPClient包，下載FTP服務上的文件，報出異常：

1，確保手工用FTP客戶端連接沒問題。
2，手工沒問題，程序也應該沒問題才是。
3，確保程序中安全CLOSE連接，FTP伺服器也是有連接限制的。
4，適當考慮重起一下FTP伺服器。

E. Linux下用C語言寫一個FTP系統程序，包含server和client兩部分

我覺得你可能沒講清楚吧，是寫一個類似FTP功能的程序（包括server和client）？還是要實現一個版FTP的server和client？前者權很簡單，先網路linux socket編程，再網路linux下文件讀寫，之後無非就是調通server和client的tcp連接之後，把讀出來的東西發過去就是了。後者要實現完整的ftp協議，如果你只是本科的話，我覺得這個確實夠難的，但這也是有開源代碼的，http://sourceforge.net/projects/libftp/，反正是大作業，慢慢看吧。不過我感覺你的需求多半是前者，否則你們老師也太BT了，這年頭誰還會自己開發ftp協議啊。。。

F. 如何從windows系統向linux系統傳送文件

方法一：安裝SSH Secure Shell Client客戶端
安裝即可登錄直接拖拉到linux，如果從linux下導出文件則需要如此操作

文件自動回到windows窗口的當前目錄；
方法2：通過windows cmd窗口命令

Microsoft Windows XP [版本 5.1.2600]
(C) 版權所有 1985-2001 Microsoft Corp.
C:\Documents and Settings\Administrator>d:
D:\>e:
step1:ftp登錄
E:\>ftp 128.8.28.212
Connected to 128.8.28.212.
220 (vsFTPd 2.2.2)
User (128.8.28.212:(none)): oracle
331 Please specify the password.
Password:
230 Login successful.
step2:查看目錄中的文件列表
ftp> cd wangxj
250 Directory successfully changed.
ftp> ls
200 PORT command successful. Consider using PASV.
150 Here comes the directory listing.
enfo_ods.dmp
enfo_ods.log
tsubject.dmp
tsubject.log
226 Directory send OK.
ftp: 收到 56 位元組，用時 0.00Seconds 56000.00Kbytes
step3:從linux當前目錄下載文
ftp> get enfo_ods.dmp200 PORT command successful. Consider using PASV150 Opening BINARY mode data connection for enfo_ods.dmp (325029888 bytes)226 Transfer complete.ftp: 收到 325029888 位元組，用時 27.39Seconds 11866.74Kbytes/sec.
ftp> get enfo_ods.log
200 PORT command successful. Consider using PASV.
150 Opening BINARY mode data connection for enfo_ods.log (13704 bytes).
226 Transfer complete.
ftp: 收到 13704 位元組，用時 0.00Seconds 13704000.00Kbytes/sec.
step4:從windows上傳文件到linux
ftp> put test.ktr;
test.ktr;: File not found
//退出ftp 或者用bye
ftp> quit
E:\>ftp 128.8.28.212
Connected to 128.8.28.212.
220 (vsFTPd 2.2.2)
User (128.8.28.212:(none)): oracle
331 Please specify the password.
Password:
230 Login successful.
ftp> put E:\test.ktr
200 PORT command successful. Consider using PASV.
150 Ok to send data.
226 Transfer complete.
ftp: 發送 23410 位元組，用時 0.00Seconds 23410000.00Kbytes/sec.
ftp>
備註：
ftp是通用協議，不區分系統的。
知道linux機器的IP即可。
開始 -> 運行，輸入cmd並回車，鍵入以下命令（前面的>為命令提示符，不用輸入）：
> ftp Linux機器的IP地址
> binary
> put windows系統本地文件全路徑 /linux系統上的目標路徑
> bye

其中，如果是文本文件，可以不用binary設置為二進制傳輸模式（默認文本模式，會自動轉換文本格式）。如果是非文本文件（例如可執行文件），建議一定要設置為 binary 模式。

G. java 使用ftp 下載文件在windows環境下正常，在linux下載不了

GET <服務端：下載的檔名> <本地端：存放的檔名>
PUT <本地端：回上傳的檔名> <服務端：存放的檔名>

下載答：
ex：從伺服器端下載一個檔名為 linux.rar 的文件到本地路徑 C:\，存放檔名為 LINUX_S.RAR。

ftp> get linux.rar c:\LINUX_S.RAR

上傳：
ex：從本地端路徑 C:\ 上傳一個檔名為 LINUX_S.RAR 的文件到伺服器，存放檔名為 linux.rar。

ftp> put c:\LINUX_S.RAR linux.rar

H. linux如何重新配置FTP文件，我是新手，配置的時候被我弄錯了！

那就可以重新生成配置文件，可以用yum源 yum remove vsftp -y 卸載後，重新在安裝一下，就可以了
下面是：Linux FTP配置文件說明

一.vsftpd說明:
LINUX下實現FTP服務的軟體很多,最常見的有vsftpd,Wu-ftpd和Proftp等.Red Hat Enterprise Linux中默認安裝的是vsftpd.
訪問FTP伺服器時需要經過驗證,只有經過了FTP伺服器的相關驗證,用戶才能訪問和傳輸文件.vsftpd提供了3種ftp登錄形式:
(1)anonymous(匿名帳號)
使用anonymous是應用廣泛的一種FTP伺服器.如果用戶在FTP伺服器上沒有帳號,那麼用戶可以以anonymous為用戶名,以自己的電子郵件地址為密碼進行登錄.當匿名用戶登錄FTP伺服器後,其登錄目錄為匿名FTP伺服器的根目錄/var/ftp.為了減輕FTP伺服器的負載,一般情況下,應關閉匿名帳號的上傳功能.
(2)real(真實帳號)
real也稱為本地帳號,就是以真實的用戶名和密碼進行登錄,但前提條件是用戶在FTP伺服器上擁有自己的帳號.用真實帳號登錄後,其登錄的目錄為用戶自己的目錄,該目錄在系統建立帳號時系統就自動創建.
(3)guest(虛擬帳號)
如果用戶在FTP伺服器上擁有帳號,但此帳號只能用於文件傳輸服務,那麼該帳號就是guest,guest是真實帳號的一種形式,它們的不同之處在於,geust登錄FTP伺服器後,不能訪問除宿主目錄以外的內容.

二.FTP相關配置文件說明
其相關配置文件有/etc/vsftpd/vsftpd.conf, /etc/vsftpd.ftpusers, /etc/vsftpd.user_list,在配置FTP伺服器時,主要是修改這些文件中的相關語句.
1.vsftpd.conf文件說明
# Example config file /etc/vsftpd/vsftpd.conf
#
# The default compiled in settings are fairly paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
# Please see vsftpd.conf.5 for all compiled in defaults.
#
# READ THIS: This example file is NOT an exhaustive list of vsftpd options.
# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
# capabilities.
#
# Allow anonymous FTP? (Beware - allowed by default if you comment this out).
anonymous_enable=YES //是否允許anonymous登錄FTP伺服器,默認是允許的.
#
# Uncomment this to allow local users to log in.
local_enable=YES //是否允許本地用戶登錄FTP伺服器,默認是允許
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES //是否允許用戶具有在FTP伺服器文件中執行寫的許可權,默認是允許
#
# Default umask for local users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
local_umask=022 //設置本地用戶的文件生成掩碼為022,默認是077
#
# Uncomment this to allow the anonymous FTP user to upload files. This only
# has an effect if the above global write enable is activated. Also, you will
# obviously need to create a directory writable by the FTP user.
#anon_upload_enable=YES
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES //是否允許匿名賬戶在FTP伺服器中創建目錄
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
dirmessage_enable=YES //激活目錄信息,當遠程用戶更改目錄時,將出現提示信息
#
# Activate logging of uploads/downloads.
xferlog_enable=YES //啟用上傳和下載日誌功能
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=YES //啟用FTP數據埠的連接請求
#
# If you want, you can arrange for uploaded anonymous files to be owned by
# a different user. Note! Using "root" for uploaded files is not
# recommended!
#chown_uploads=YES
#chown_username=whoever
#
# You may override where the log file goes if you like. The default is shown
# below.
#xferlog_file=/var/log/vsftpd.log //設置日誌文件的文件名和存儲路徑,這是默認的
#
# If you want, you can have your log file in standard ftpd xferlog format
xferlog_std_format=YES//是否使用標準的ftpd xferlog日誌文件格式
#
# You may change the default value for timing out an idle session.
#idle_session_timeout=600 //設置空閑的用戶會話中斷時間,默認是10分鍾
#
# You may change the default value for timing out a data connection.
#data_connection_timeout=120//設置數據連接超時時間,默認是120秒.
#
# It is recommended that you define on your system a unique user which the
# ftp server can use as a totally isolated and unprivileged user.
#nopriv_user=ftpsecure
#
# Enable this and the server will recognise asynchronous ABOR requests. Not
# recommended for security (the code is non-trivial). Not enabling it,
# however, may confuse older FTP clients.
#async_abor_enable=YES
#
# By default the server will pretend to allow ASCII mode but in fact ignore
# the request. Turn on the below options to have the server actually do ASCII
# mangling on files when in ASCII mode.
# Beware that turning on ascii_download_enable enables malicious remote parties
# to consume your I/O resources, by issuing the command "SIZE /big/file" in
# ASCII mode.
# These ASCII options are split into upload and download because you may wish
# to enable ASCII uploads (to prevent uploaded scripts etc. from breaking),
# without the DoS risk of SIZE and ASCII downloads. ASCII mangling should be
# on the client anyway..
#ascii_upload_enable=YES
#ascii_download_enable=YES //是否允許使用ASCII格式來上傳和下載文件
#
# You may fully customise the login banner string:
#ftpd_banner=Welcome to blah FTP service.//在FTP伺服器中設置歡迎登錄的信息.
#
# You may specify a file of disallowed anonymous e-mail addresses. Apparently
# useful for combatting certain DoS attacks.
#deny_email_enable=YES
# (default follows)
#banned_email_file=/etc/vsftpd.banned_emails
#
# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
#chroot_list_enable=YES //如果希望用戶登錄後不能切換到自己目錄以外的其它目錄,需要設置該項,如果設置chroot_list_enable=YES,那麼只允許/etc/vsftpd.chroot_list中列出的用戶具有該功能.如果希望所有的本地用戶都執行者chroot,可以增加一行:chroot_local_user=YES
# (default follows)
#chroot_list_file=/etc/vsftpd.chroot_list
#
# You may activate the "-R" option to the builtin ls. This is disabled by
# default to avoid remote users being able to cause excessive I/O on large
# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
# the presence of the "-R" option, so there is a strong case for enabling it.
#ls_recurse_enable=YES
pam_service_name=vsftpd //設置PAM認證服務的配置文件名稱,該文件存放在/etc/pam.d/目錄下.
userlist_enable=YES //用戶列表中的用戶是否允許登錄FTP伺服器,默認是不允許
#enable for standalone mode
listen=YES //使vsftpd 處於獨立啟動模式
tcp_wrappers=YES //使用tcp_wrqppers作為主機訪問控制方式
2.vsftpd.ftpusers文件說明
這個文件是用來記錄"不允許"登錄到FTP伺服器的用戶,通常是一些系統默認的用戶.
下面是該文件中默認的不允許登錄的名單:
# Users that are not allowed to login via ftp
root //默認情況下,root和它以下的用戶是不允許登錄FTP伺服器的.可以將不允許登錄的用戶添加到這里來.但切記每個用戶都要單獨佔用一行.
bin
daemon
adm
lp
sync
shutdown
halt
mail
news
uucp
operator
games
nobody
3.vsftpd.user_list文件說明
其實它的內容跟上面那個文件內容一樣,只是在系統對文件vsftpd.conf 進行檢測時,會檢測到"userlist_deny=YES",因此這個文件必須存在.下面是這個文件的內容.
# vsftpd userlist
# If userlist_deny=NO, only allow users in this file
# If userlist_deny=YES (default), never allow users in this file, and
# do not even prompt for a password.
# Note that the default vsftpd pam config also checks /etc/vsftpd.ftpusers
# for users that are denied.
root
bin
daemon
adm
lp
sync
shutdown
halt
mail
news
uucp
operator
games
nobody

I. ftpclient changeWorkingDirectory 在linux 下返回值為false，請問這個什麼問題

linux下面登錄到FTP第一次切換到指定目錄時，可以直接changeWorkingDirectory，當再次重復調滾旅鏈用changeWorkingDirectory仍然切換到這個指定目鎮物錄的時候(一大孫般你登錄ftp後，批量上傳文件的時候，根據你的代碼，可能會出現重復切換相同目錄的情況)，在lilux下的ftp下重復切換到指定目錄會返回false，這與window中的ftp不一樣，window中可以重復切換，而liliux中不行，所以在lilux中的ftp中你最好判定是否第一次切換目錄，如果是第一次切換到指定目錄，就調用changeWorkingDirectory，當你要上傳下一個文件的時候，就不用再次changeWorkingDirectory了

J. linux環境下，在java中用sun.net.ftp.FtpClient類去讀取文件名含有「點號」的文件時報錯找不到文件

public class P1{
private int[][] a=null;
private int rownum=0,colnum=0;
//存儲每行中最小的那個數的行和列,如"1,2"---第一行，第二列
private int[] rows=null;
//存儲每列中最大的那個數的行和列,如"1,2"---第一行，第二列
private int[] cols=null;
private int num=0;
P1(int[][] a,int row,int col){
this.a = a;
this.rownum=row;
this.colnum=col;
rows = new int[row];
cols = new int[col];
}