轉(zhuǎn)載地址：
http://blog.csdn.net/hbcui1984/archive/2008/07/27/2720204.aspx
在JAVA程序中，經(jīng)常需要和FTP打交道，比如向FTP服務(wù)器上傳文件、下載文件，本文簡單介紹如何利用jakarta commons中的FTPClient（在commons-net包中）實現(xiàn)上傳下載文件。
一、上傳文件
???????? 原理就不介紹了，大家直接看代碼吧
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public
static
boolean
uploadFile(String url,
int
port,String username, String password, String path, String filename, InputStream input) { ??
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????
boolean
success =
false
; ??
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???? FTPClient ftp =
new
FTPClient(); ??
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try
{ ??
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????????
int
reply; ??
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???????? ftp.connect(url, port);
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????????
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???????? ftp.login(username, password);
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???????? reply = ftp.getReplyCode(); ??
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????????
if
(!FTPReply.isPositiveCompletion(reply)) { ??
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???????????? ftp.disconnect(); ??
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????????????
return
success; ??
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???????? } ??
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???????? ftp.changeWorkingDirectory(path); ??
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???????? ftp.storeFile(filename, input);????????? ??
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???????? ??
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???????? input.close(); ??
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???????? ftp.logout(); ??
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???????? success =
true
; ??
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???? }
catch
(IOException e) { ??
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???????? e.printStackTrace(); ??
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finally
{ ??
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????????
if
(ftp.isConnected()) { ??
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????????????
try
{ ??
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???????????????? ftp.disconnect(); ??
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???????????? }
catch
(IOException ioe) { ??
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???????????? } ??
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???????? } ??
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return
success; ??
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}
/**
* Description: 向FTP服務(wù)器上傳文件
* @Version1.0 Jul 27, 2008 4:31:09 PM by 崔紅保（cuihongbao@d-heaven.com）創(chuàng)建
* @param url FTP服務(wù)器hostname
* @param port FTP服務(wù)器端口
* @param username FTP登錄賬號
* @param password FTP登錄密碼
* @param path FTP服務(wù)器保存目錄
* @param filename 上傳到FTP服務(wù)器上的文件名
* @param input 輸入流
* @return 成功返回true，否則返回false
*/
public static boolean uploadFile(String url,int port,String username, String password, String path, String filename, InputStream input) {
boolean success = false;
FTPClient ftp = new FTPClient();
try {
int reply;
ftp.connect(url, port);//連接FTP服務(wù)器
//如果采用默認端口，可以使用ftp.connect(url)的方式直接連接FTP服務(wù)器
ftp.login(username, password);//登錄
reply = ftp.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) {
ftp.disconnect();
return success;
}
ftp.changeWorkingDirectory(path);
ftp.storeFile(filename, input);
input.close();
ftp.logout();
success = true;
} catch (IOException e) {
e.printStackTrace();
} finally {
if (ftp.isConnected()) {
try {
ftp.disconnect();
} catch (IOException ioe) {
}
}
}
return success;
}
下面我們寫兩個小例子：
1.將本地文件上傳到FTP服務(wù)器上，代碼如下：
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@Test
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public
void
testUpLoadFromDisk(){ ??
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try
{ ??
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???????? FileInputStream in=
new
FileInputStream(
new
File(
"D:/test.txt"
)); ??
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boolean
flag = uploadFile(
"127.0.0.1"
,
21
,
"test"
,
"test"
,
"D:/ftp"
,
"test.txt"
, in); ??
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???????? System.out.println(flag); ??
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???? }
catch
(FileNotFoundException e) { ??
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???????? e.printStackTrace(); ??
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}
2.在FTP服務(wù)器上生成一個文件，并將一個字符串寫入到該文件中
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@Test
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public
void
testUpLoadFromString(){ ??
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try
{ ??
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???????? InputStream input =
new
ByteArrayInputStream(
"test ftp"
.getBytes(
"utf-8"
)); ??
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boolean
flag = uploadFile(
"127.0.0.1"
,
21
,
"test"
,
"test"
,
"D:/ftp"
,
"test.txt"
, input); ??
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???????? System.out.println(flag); ??
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???? }
catch
(UnsupportedEncodingException e) { ??
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???????? e.printStackTrace(); ??
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}
二、下載文件
?????? 從FTP服務(wù)器下載文件的代碼也很簡單，參考如下：
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public
static
boolean
downFile(String url,
int
port,String username, String password, String remotePath,String fileName,String localPath) { ??
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boolean
success =
false
; ??
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???? FTPClient ftp =
new
FTPClient(); ??
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try
{ ??
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int
reply; ??
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???????? ftp.connect(url, port); ??
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????????
??
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???????? ftp.login(username, password);
??
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???????? reply = ftp.getReplyCode(); ??
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????????
if
(!FTPReply.isPositiveCompletion(reply)) { ??
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???????????? ftp.disconnect(); ??
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????????????
return
success; ??
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???????? } ??
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???????? ftp.changeWorkingDirectory(remotePath);
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???????? FTPFile[] fs = ftp.listFiles(); ??
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for
(FTPFile ff:fs){ ??
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if
(ff.getName().equals(fileName)){ ??
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???????????????? File localFile =
new
File(localPath+
"/"
+ff.getName()); ??
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???????????????? ??
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???????????????? OutputStream is =
new
FileOutputStream(localFile); ??
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???????????????? ftp.retrieveFile(ff.getName(), is); ??
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???????????????? is.close(); ??
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???????????? } ??
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???????? } ??
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???????? ??
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???????? ftp.logout(); ??
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???????? success =
true
; ??
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???? }
catch
(IOException e) { ??
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???????? e.printStackTrace(); ??
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???? }
finally
{ ??
-
????????
if
(ftp.isConnected()) { ??
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????????????
try
{ ??
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???????????????? ftp.disconnect(); ??
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???????????? }
catch
(IOException ioe) { ??
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???????????? } ??
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???????? } ??
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???? }???
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return
success; ??
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}