java使用apache commons连接ftp修改ftp文件名失败原因

java使用apache commons连接ftp修改ftp文件名失败原因

今天被ftp上中文名修改坑了好久

项目用的是 apache commons 里的 FtpClient 实现的对ftp文件的上传下载操作，今天增加了业务要修改ftp上的文件名，然后就一直的报错，问题是它修改名字的方法只返回一个boolean，没有异常，这就很蛋疼了，找了好久才发现是中文的名字的原因

改名

直接上代码

package net.codejava.ftp;

import java.io.IOException;

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

public class FTPRenamer {

public static void main(String[] args) {

String server = "ftpserver.com";

int port = 21;

String user = "username";

String pass = "password";

FTPClient ftpClient = new FTPClient();

try {

ftpClient.connect(server, port);

ftpClient.login(user, pass);

// renaming directory

String oldDir = "/photo";

String newDir = "/photo_2012";

boolean success = ftpClient.rename(oldDir, newDir);

if (success) {

System.out.println(oldDir + " was successfully renamed to: "

+ newDir);

} else {

System.out.println("Failed to rename: " + oldDir);

}

// renaming file

String oldFile = "/work/error.png";

String newFile = "/work/screenshot.png";

success = ftpClient.rename(oldFile, newFile);

if (success) {

System.out.println(oldFile + " was successfully renamed to: "

+ newFile);

} else {

System.ouUZiIBwt.println("Failed to rename: " + oldFile);

}

ftpClient.logout();

ftpClient.disconnect();

} catch (IOException ex) {

ex.printStackTrace();

} finally {

if (ftpClient.isConnected()) {

try {

ftpClient.logout();

ftpClient.disconnect();

} catch (IOException ex) {

ex.printStackTrace();

}

}

}

}

}

如果修改的名字里没有中文，用上面的代码就够了，但如果有中文就要对文件名进行转码了，转码代码如下

// renaming file

String oldFile = "/work/你好.png";

String newFile = "/work/世界.png";

success = ftpClient.rename(

new String(oldFile.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1),

new String(newFile.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1)

);

这样再修改名字就没有问题了

顺便记录一下上传、下载、删除、检查文件是否存在， 同样的，如果有中文名，最好先转一下码再进行操作

上传

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import org.apache.commons.net.ftp.FTP;

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

/**

* A program that demonstrates how to upload files from local computer

* to a remote FTP server using Apache Commons Net API.

* @author codejava.net

*/

public class FTPUploadFileDemo {

public static void main(String[] args) {

String server = "myserver.com";

int port = 21;

String user = "user";

String pass = "pass";

FTPClient ftpClient = new FTPClient();

try {

ftpClient.connect(server, port);

ftpClient.login(user, pass);

ftpClient.enterLocalPassiveMode();

ftpClient.setFileType(FTP.BINARY_FILE_TYPE);

// APPROACH #1: uploads first file using an InputStream

File firstLocalFile = new File("D:/Test/Projects.zip");

String firstRemoteFile = "Projects.zip";

InputStream inputStream = new FileInputStream(firstLocalFile);

System.out.println("Start uploading first file");

boolean done = ftpClient.storeFile(firstRemoteFile, inputStream);

inputStream.close();

if (done) {

System.out.println("The first file is uploaded successfully.");

}

// APPROACH #2: uploads second file using an OutputStream

File secondLocalFile = new File("E:/Test/Report.doc");

String secondRemoteFile = "test/Report.doc";

inputStream = new FileInputStream(secondLocalFile);

System.out.println("Start uploading second file");

OutputStream outputStream = ftpClient.storeFileStream(secondRemoteFile);

byte[] bytesIn = new byte[4096];

int read = 0;

while ((read = inputStream.read(bytesIn)) != -1) {

outputStream.write(bytesIn, 0, read);

}

inputStream.close();

outputStream.close();

boolean completed = ftpClient.completePendingCommand();

if (completed) {

System.out.println("The second file is uploaded successfully.");

}

} catch (IOException ex) {

System.out.println("Error: " + ex.getMessage());

ex.printStackTrace();

} finally {

try {

if (ftpClient.isConnected()) {

ftpClient.logout();

ftpClient.disconnect();

}

} catch (IOException ex) {

ex.printStackTrace();

}

}

}

}

下载

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import org.apache.commons.net.ftp.FTP;

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

/**

* A program demonstrates how to upload files from local computer to a remote

* FTP server using Apache Commons Net API.

* @author codejava.net

*/

public class FTPDownloadFileDemo {

public static void main(String[] args) {

String server = "myserver.com";

int port = 21;

String user = "user";

String pass = "pass";

FTPClient ftpClient = new FTPClient();

try {

ftpClient.connect(server, port);

ftpClient.login(user, pass);

ftpClient.enterLocalPassiveMode();

ftpClient.setFileType(FTP.BINARY_FILE_TYPE);

// APPROACH #1: using retrieveFile(String, OutputStream)

String remoteFile1 = "/test/video.mp4";

File downloadFile1 = new File("D:/Downloads/video.mp4");

OutputStream outputStream1 = new BufferedOutputStream(new FileOutputStream(downloadFile1));

boolean success = ftpClient.retrieveFile(remoteFile1, outputStream1);

outputStream1.close();

if (success) {

System.out.println("File #1 has been downloaded successfully.");

}

// APPROACH #2: using InputStream retrieveFileStream(String)

String remoteFile2 = "/test/song.mp3";

File downloadFile2 = new File("D:/Downloads/song.mp3");

OutputStream outputStream2 = new BufferedOutputStream(new FileOutputStream(downloadFile2));

InputStream inputStream = ftpClient.retrieveFileStream(remoteFile2);

byte[] bytesArray = new byte[4096];

int bytesRead = -1;

while ((bytesRead = inputStream.read(bytesArray)) != -1) {

outputStream2.write(bytesArray, 0, bytesRead);

}

success = ftpClient.completePendingCommand();

if (success) {

System.out.println("File #2 has been downloaded successfully.");

}

outputStream2.close();

inputStream.close();

} catch (IOException ex) {

System.out.println("Error: " + ex.getMessage());

ex.printStackTrace();

} finally {

try {

if (ftpClient.isConnected()) {

ftpClient.logout();

ftpClient.disconnect();

}

} catch (IOException ex) {

ex.printStackTrace();

}

}

}

}

删除

import java.io.IOException;

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

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

public class FTPDeleteFileDemo {

public static void main(String[] args) {

String server = "myserver.com";

int port = 21;

String user = "user";

String pass = "pass";

FTPClient ftpClient = new FTPClient();

try {

ftpClient.connect(server, port);

int replyCode = ftpClient.getReplyCode();

if (!FTPReply.isPositiveCompletion(replyCode)) {

System.out.println("Connect failed");

return;

}

boolean success = ftpClient.login(user, pass);

if (!success) {

System.out.println("Could not login to the server");

return;

}

String fileToDelete = "/repository/video/cool.mp4";

boolean deleted = ftpClient.deleteFile(fileToDelete);

if (deleted) {

System.out.println("The file was deleted successfully.");

} else {

System.out.println("Could not delete the file, it may not exist.");

}

} catch (IOException ex) {

System.out.println("Oh no, there was an error: " + ex.getMessage());

ex.printStackTrace();

} finally {

// logs out and disconnects from server

try {

if (ftpClient.isConnected()) {

ftpClient.logout();

ftpClient.disconnect();

}

} catch (IOException ex) {

ex.printStackTrace();

}

}

}

}

检查文件/文件夹是否存在

package net.codejava.ftp;

import java.io.IOException;

import java.io.InputStream;

import java.net.SocketException;

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

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

/**

* This program demonstrates how to determine existence of a specific

* file/directory on a remote FTP server.

* @author codejava.net

*

*/

public class FTPCheckFileExists {

private FTPClient ftpClient;

private int returnCode;

/**

* Determines whether a directory exists or not

* @param dirPath

* @return true if exists, false otherwise

* @throws IOException thrown if anhttp://y I/O error occurred.

*/

boolean checkDirectoryExists(String dirPath) throws IOException {

ftpClient.changeWorkingDirectory(dirPath);

returnCode = ftpClient.getReplyCode();

if (returnCode == 550) {

return false;

}

return true;

}

/**

* Determines whether a file exists or not

* @param filePath

* @return true if exists, false otherwise

* @throws IOException thrown if any I/O error occurred.

*/

boolean checkFileExists(String filePath) throws IOException {

InputStream inputStream = ftpClient.retrieveFileStream(filePath);

returnCode = ftpClient.getReplyCode();

if (inputStream == null || returnCode == 550) {

return false;

}

return true;

}

/**

* Connects to a remote FTP server

*/

void connect(String hostname, int port, String username, String password)

throws SocketException, IOException {

ftpClient = new FTPClient();

ftpClient.connect(hostname, port);

returnCode = ftpClient.getReplyCode();

if (!FTPReply.isPositiveCompletion(returnCode)) {

throw new IOException("Could not connect");

}

boolean loggedIn = ftpClient.login(username, password);

if (!loggedIn) {

throw new IOException("Could not login");

}

System.out.println("Connected and logged in.");

}

/**

* Logs out and disconnects from the server

*/

void logout() throws IOException {

if (ftpClient != null && ftpClient.isConnected()) {

ftpClient.logout();

ftpClient.disconnect();

System.out.println("Logged out");

}

}

/**

* Runs this program

*/

public static void main(String[] args) {

String hostname = "yourserver.com";

int port = 21;

String usernhttp://ame = "your_user";

String password = "your_password";

String dirPath = "Photo";

String filePath = "Music.mp4";

FTPCheckFileExists ftpApp = new FTPCheckFileExists();

try {

ftpApp.connect(hostname, port, username, password);

boolean exist = ftpApp.checkDirectoryExists(dirPath);

System.out.println("Is directory " + dirPath + " exists? " + exist);

exist = ftpApp.checkFileExists(filePath);

System.out.println("Is file " + filePath + " exists? " + exist);

} catch (IOException ex) {

ex.printStackTrace();

} finally {

try {

ftpApp.logout();

} catch (IOException ex) {

ex.printStackTrace();

}

}

}

}

参考

https://codejava.net/java-se/ftp/how-to-start-ftp-programming-with-java

总结

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