用java怎么获取ftp上的文件

public class FtpClientUtil {

FtpClient ftpClient

private String server

private int port

private String userName

private String userPassword

public FtpClientUtil(String server,int port,String userName,String userPassword)

{

this.server=server

this.port=port

this.userName=userName

this.userPassword=userPassword

}

/**

* 链接到服务器

* @return

*/

public boolean open()

{

if(ftpClient!=null&&ftpClient.serverIsOpen())

return true

try

{

ftpClient= new FtpClient()

ftpClient.openServer(server,port)

ftpClient.login(userName, userPassword)

ftpClient.binary()

return true

}

catch(Exception e)

{

e.printStackTrace()

ftpClient=null

return false

}

}

public boolean cd(String dir){

boolean f = false

try {

ftpClient.cd(dir)

} catch (IOException e) {

Logs.error(e.toString())

return f

}

return true

}

/**

* 上传文件到FTP服务器

* @param localPathAndFileName 本地文件目录和文件名

* @param ftpFileName 上传后的文件名

* @param ftpDirectory FTP目录如:/path1/pathb2/,如果目录不存在回自动创建目录

* @throws Exception

*/

public boolean upload(String localDirectoryAndFileName,String ftpFileName,String ftpDirectory)throws Exception {

if(!open())

return false

FileInputStream is=null

TelnetOutputStream os=null

try

{

char ch = ' '

if (ftpDirectory.length() >0)

ch = ftpDirectory.charAt(ftpDirectory.length() - 1)

for (ch == '/' || ch == '\\'ch = ftpDirectory.charAt(ftpDirectory.length() - 1))

ftpDirectory = ftpDirectory.substring(0, ftpDirectory.length() - 1)

int slashIndex = ftpDirectory.indexOf(47)

int backslashIndex = ftpDirectory.indexOf(92)

int index = slashIndex

String dirall = ftpDirectory

if (backslashIndex != -1 &&(index == -1 || index >backslashIndex))

index = backslashIndex

String directory = ""烂激袭铅启

while (index != -1) {

if (index >0) {

String dir = dirall.substring(0, index)

directory = directory + "/"饥兄 + dir

ftpClient.sendServer("XMKD " + directory + "\r\n")

ftpClient.readServerResponse()

}

dirall = dirall.substring(index + 1)

slashIndex = dirall.indexOf(47)

backslashIndex = dirall.indexOf(92)

index = slashIndex

if (backslashIndex != -1 &&(index == -1 || index >backslashIndex))

index = backslashIndex

}

ftpClient.sendServer("XMKD " + ftpDirectory + "\r\n")

ftpClient.readServerResponse()

os = ftpClient.put(ftpDirectory + "/"

+ ftpFileName)

File file_in = new File(localDirectoryAndFileName)

is = new FileInputStream(file_in)

byte bytes[] = new byte[1024]

int i

while ((i = is.read(bytes)) != -1)

os.write(bytes, 0, i)

//清理垃圾

return true

}

catch(Exception e)

{

e.printStackTrace()

return false

}

finally

{

if (is != null)

is.close()

if (os != null)

os.close()

}

}

/**

* 从FTP服务器上下载文件并返回下载文件长度

* @param ftpDirectoryAndFileName

* @param localDirectoryAndFileName

* @return

* @throws Exception

*/

public long download(String ftpDirectoryAndFileName,String localDirectoryAndFileName)throws Exception

{

long result = 0

if(!open())

return result

TelnetInputStream is = null

FileOutputStream os = null

try

{

is = ftpClient.get(ftpDirectoryAndFileName)

java.io.File outfile = new java.io.File(localDirectoryAndFileName)

os = new FileOutputStream(outfile)

byte[] bytes = new byte[1024]

int c

while ((c = is.read(bytes)) != -1)

{

os.write(bytes, 0, c)

result = result + c

}

}

catch (Exception e)

{

throw e

}

finally

{

if (is != null)

is.close()

if (os != null)

os.close()

}

return result

}

/**

* 返回FTP目录下的文件列表

* @param ftpDirectory

* @return

*/

public List<String>getFileNameList(String ftpDirectory)

{

List<String>list = new ArrayList<String>()

if(!open())

return list

try

{

DataInputStream dis = new DataInputStream(ftpClient.nameList(ftpDirectory))

String filename = ""

while((filename=dis.readLine())!=null)

{

list.add(filename)

}

} catch (Exception e)

{

e.printStackTrace()

}

return list

}

/**

* 删除FTP上的文件

* @param ftpDirAndFileName

*/

public boolean deleteFile(String ftpDirAndFileName)

{

if(!open())

return false

ftpClient.sendServer("DELE "+ftpDirAndFileName+"\r\n")

return true

}

/**

* 删除FTP目录

* @param ftpDirectory

*/

public boolean deleteDirectory(String ftpDirectory)

{

if(!open())

return false

ftpClient.sendServer("XRMD "+ftpDirectory+"\r\n")

return true

}

/**

* 关闭链接

*/

public void close()

{

try

{

if(ftpClient!=null&&ftpClient.serverIsOpen())

ftpClient.closeServer()

}catch(Exception e)

{

}

}

}望采纳，谢谢。

http的话就用

httpclient

。open后，可以返回一个

InputStream

。这个就是你要读到

文件流

。

原理的话，参考你用浏览器打开这个链接显示的内容。

这个返回的是一个启州宏HTML网页，需要你解析出里面的文字（一般来说取body中间的内容就行）

其实对于这种文件一般用FTP来下载的。楼上写的那个不对，悄册哈哈。

需要的话自己最好去查一下，怎么用，我有代迹闭码，不过告诉你的话也不太好？

URL

url

=

new

URL("http://你的地址")

URLConnection

connection

=

url.openConnection()

InputStream

is

=

connection.getInputStream()

BufferedReader

br

=

new

BufferedReader(new

InputStreamReader(is,"gb2312"))

下面就是解析这个字符串来，自己来吧

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