ftp工具类：上传与下载文件

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准备工作

服务器已经配置好ftp服务

linux服务器搭建ftp服务： https://program.blog.csdn.net/article/details/88825921

需要用到的jar包：

<dependency>
	<groupId>commons-net</groupId>
	<artifactId>commons-net</artifactId>
	<version>3.3</version>
</dependency>

配置文件

• application.yml

# 配置ftp服务器信息
ftp: 
  # ftp服务器的IP地址
  url: 127.0.0.0
  # 默认端口是21
  port: 21
  username: ftpuser
  password: ftpuser
  # ftp服务器存放文件的路径
  remotePath: /data/ftp
  # 本地需要上传的文件的路径
  localDir: D:/test
  # ftp上文件下载到本地存放的路径
  downDir: D:/test

• FtpConfig配置信息类

@Getter
@Component
public class FtpConfig { 
   
	/** * ftp服务器地址 */
	@Value("${ftp.url}")
	private String url;
	
	/** * ftp服务器端口 */
	@Value("${ftp.port}")
	private int port;
	
	/** * ftp服务器用户名 */
	@Value("${ftp.username}")
	private String username;
	
	/** * ftp服务器密码 */
	@Value("${ftp.password}")
	private String password;
	
	/** * ftp服务器存放文件的路径 */
	@Value("${ftp.remotePath}")
	private String remotePath;
	
	/** * 本地需要上传的文件的路径 */
	@Value("${ftp.localDir}")
	private String localDir;
	
	/** * 下载文件时，存放在本地的路径 */
	@Value("${ftp.downDir}")
	private String downDir;
	
}

工具类FtpUtil内容

@Slf4j(topic="文件上传/下载===ftp服务器:")
public class FtpUtil { 

private static FTPClient mFTPClient = new FTPClient();
private static FtpUtil ftp = new FtpUtil();
public FtpUtil() { 

// 在控制台打印操作过程
mFTPClient.addProtocolCommandListener(new PrintCommandListener(new PrintWriter(System.out)));
}
/** * 上传文件到ftp服务器 */
public static boolean ftpUpload(String fileName, String ftpUrl, int ftpPort,
String ftpUsername, String ftpPassword, String ftpLocalDir, String ftpRemotePath) { 

boolean result = false;
try { 

boolean isConnection = ftp.openConnection(ftpUrl, ftpPort, ftpUsername, ftpPassword);
if (isConnection) { 

boolean isSuccess = ftp.upload(ftpRemotePath, ftpLocalDir + "/" + fileName);
if (isSuccess) { 

log.info("文件上传成功！");
result = true;
} else { 

log.info("文件上传失败！");
result = false;
}
ftp.logout();
} else { 

log.info("链接ftp服务器失败，请检查配置信息是否正确！");
result = false;
}
} catch (SocketException e) { 

e.printStackTrace();
} catch (IOException e) { 

e.printStackTrace();
}
return result;
}
/** * 从ftp服务器下载文件到本地 */
public static boolean ftpDownload(String fileName, String ftpUrl, int ftpPort,
String ftpUsername, String ftpPassword, String ftpRemotePath, String ftpDownDir) { 

boolean result = false;
try { 

boolean isConnection = ftp.openConnection(ftpUrl, ftpPort, ftpUsername, ftpPassword);
if (isConnection) { 

boolean isDownloadOk = ftp.downLoad(fileName, ftpDownDir);
boolean isCreateOk = ftp.createDirectory(ftpRemotePath, ftp.mFTPClient);
if (isDownloadOk && isCreateOk) { 

log.info("文件下载成功！");
result = true;
} else { 

log.info("文件下载失败！");
result = false;
}
ftp.logout();
} else { 

log.info("链接ftp服务器失败，请检查配置信息是否正确！");
result = false;
}
} catch (SocketException e) { 

e.printStackTrace();
} catch (IOException e) { 

e.printStackTrace();
}
return result;
}
/** * 连接ftp服务器 * * @param host * ip地址 * @param port * 端口号 * @param account * 账号 * @param pwd * 密码 * @return 是否连接成功 * @throws SocketException * @throws IOException */
private boolean openConnection(String host, int port, String account, String pwd)
throws SocketException, IOException { 

mFTPClient.setControlEncoding("UTF-8");
mFTPClient.connect(host, port);
if (FTPReply.isPositiveCompletion(mFTPClient.getReplyCode())) { 

mFTPClient.login(account, pwd);
if (FTPReply.isPositiveCompletion(mFTPClient.getReplyCode())) { 

System.err.println(mFTPClient.getSystemType());
FTPClientConfig config = new FTPClientConfig(mFTPClient.getSystemType().split(" ")[0]);
config.setServerLanguageCode("zh");
mFTPClient.configure(config);
return true;
}
}
disConnection();
return false;
}
/** * 登出并断开连接 */
public void logout() { 

System.err.println("logout");
if (mFTPClient.isConnected()) { 

System.err.println("logout");
try { 

mFTPClient.logout();
disConnection();
} catch (IOException e) { 

e.printStackTrace();
}
}
}
/** * 断开连接 */
private void disConnection() { 

if (mFTPClient.isConnected()) { 

try { 

mFTPClient.disconnect();
} catch (IOException e) { 

e.printStackTrace();
}
}
}
/** * 下载文件到本地地址 * * @param remotePath * 远程地址 * @param loacal * 本地地址 * @throws IOException */
public boolean downLoad(String remotePath, String localDir) throws IOException { 

// 进入被动模式
mFTPClient.enterLocalPassiveMode();
// 以二进制进行传输数据
mFTPClient.setFileType(FTP.BINARY_FILE_TYPE);
FTPFile[] ftpFiles = mFTPClient.listFiles(remotePath);
if (ftpFiles == null || ftpFiles.length == 0) { 

log.info("远程文件不存在");
return false;
} else if (ftpFiles.length > 1) { 

log.info("远程文件是文件夹");
return false;
}
long lRemoteSize = ftpFiles[0].getSize();
// 本地文件的地址
File localFileDir = new File(localDir);
if (!localFileDir.exists()) { 

localFileDir.mkdirs();
}
File localFile = new File(localFileDir, ftpFiles[0].getName());
long localSize = 0;
FileOutputStream fos = null;
if (localFile.exists()) { 

if (localFile.length() == lRemoteSize) { 

System.err.println("已经下载完毕");
return true;
} else if (localFile.length() < lRemoteSize) { 

// 要下载的文件存在，进行断点续传
localSize = localFile.length();
mFTPClient.setRestartOffset(localSize);
fos = new FileOutputStream(localFile, true);
}
}
if (fos == null) { 

fos = new FileOutputStream(localFile);
}
InputStream is = mFTPClient.retrieveFileStream(remotePath);
byte[] buffers = new byte[1024];
long step = lRemoteSize / 10;
long process = localSize / step;
int len = -1;
while ((len = is.read(buffers)) != -1) { 

fos.write(buffers, 0, len);
localSize += len;
long newProcess = localSize / step;
if (newProcess > process) { 

process = newProcess;
System.err.println("下载进度:" + process);
}
}
is.close();
fos.close();
boolean isDo = mFTPClient.completePendingCommand();
if (isDo) { 

System.err.println("下载成功");
} else { 

System.err.println("下载失败");
}
return isDo;
}
/** * 创建远程目录 * * @param remote * 远程目录 * @param ftpClient * ftp客户端 * @return 是否创建成功 * @throws IOException */
public boolean createDirectory(String remote, FTPClient ftpClient) throws IOException { 

String dirctory = remote.substring(0, remote.lastIndexOf("/") + 1);
if (!dirctory.equalsIgnoreCase("/") && !ftpClient.changeWorkingDirectory(dirctory)) { 

int start = 0;
int end = 0;
if (dirctory.startsWith("/")) { 

start = 1;
}
end = dirctory.indexOf("/", start);
while (true) { 

String subDirctory = remote.substring(start, end);
if (!ftpClient.changeWorkingDirectory(subDirctory)) { 

if (ftpClient.makeDirectory(subDirctory)) { 

ftpClient.changeWorkingDirectory(subDirctory);
} else { 

System.err.println("创建目录失败");
return false;
}
}
start = end + 1;
end = dirctory.indexOf("/", start);
if (end <= start) { 

break;
}
}
}
return true;
}
/** * 上传的文件 * * @param remotePath * 上传文件的路径地址（文件夹地址） * @param localPath * 本地文件的地址 * @throws IOException * 异常 */
public boolean upload(String remotePath, String localPath) throws IOException { 

// 进入被动模式
mFTPClient.enterLocalPassiveMode();
// 以二进制进行传输数据
mFTPClient.setFileType(FTP.BINARY_FILE_TYPE);
File localFile = new File(localPath);
if (!localFile.exists()) { 

System.err.println("本地文件不存在");
return false;
}
String fileName = localFile.getName();
if (remotePath.contains("/")) { 

boolean isCreateOk = createDirectory(remotePath, mFTPClient);
if (!isCreateOk) { 

System.err.println("文件夹创建失败");
return false;
}
}
// 列出ftp服务器上的文件
FTPFile[] ftpFiles = mFTPClient.listFiles(remotePath);
long remoteSize = 0l;
String remoteFilePath = remotePath + "/" + fileName;
if (ftpFiles.length > 0) { 

FTPFile mFtpFile = null;
for (FTPFile ftpFile : ftpFiles) { 

if (ftpFile.getName().endsWith(fileName)) { 

mFtpFile = ftpFile;
break;
}
}
if (mFtpFile != null) { 

remoteSize = mFtpFile.getSize();
if (remoteSize == localFile.length()) { 

System.err.println("文件已经上传成功");
return true;
}
if (remoteSize > localFile.length()) { 

if (!mFTPClient.deleteFile(remoteFilePath)) { 

System.err.println("服务端文件操作失败");
} else { 

boolean isUpload = uploadFile(remoteFilePath, localFile, 0);
System.err.println("是否上传成功：" + isUpload);
}
return true;
}
if (!uploadFile(remoteFilePath, localFile, remoteSize)) { 

System.err.println("文件上传成功");
return true;
} else { 

// 断点续传失败删除文件，重新上传
if (!mFTPClient.deleteFile(remoteFilePath)) { 

System.err.println("服务端文件操作失败");
} else { 

boolean isUpload = uploadFile(remoteFilePath, localFile, 0);
System.err.println("是否上传成功：" + isUpload);
}
return true;
}
}
}
boolean isUpload = uploadFile(remoteFilePath, localFile, remoteSize);
System.err.println("是否上传成功：" + isUpload);
return isUpload;
}
/** * 上传文件 * * @param remoteFile * 包含文件名的地址 * @param localFile * 本地文件 * @param remoteSize * 服务端已经存在的文件大小 * @return 是否上传成功 * @throws IOException */
private boolean uploadFile(String remoteFile, File localFile, long remoteSize) throws IOException { 

long step = localFile.length() / 10;
long process = 0;
long readByteSize = 0;
RandomAccessFile randomAccessFile = new RandomAccessFile(localFile, "r");
OutputStream os = mFTPClient.appendFileStream(remoteFile);
if (remoteSize > 0) { 

// 已经上传一部分的时候就要进行断点续传
process = remoteSize / step;
readByteSize = remoteSize;
randomAccessFile.seek(remoteSize);
mFTPClient.setRestartOffset(remoteSize);
}
byte[] buffers = new byte[1024];
int len = -1;
while ((len = randomAccessFile.read(buffers)) != -1) { 

os.write(buffers, 0, len);
readByteSize += len;
long newProcess = readByteSize / step;
if (newProcess > process) { 

process = newProcess;
System.err.println("当前上传进度为：" + process);
}
}
os.flush();
randomAccessFile.close();
os.close();
boolean result = mFTPClient.completePendingCommand();
return result;
}
}

访问测试

@RestController
@RequestMapping(value = "/ftp")
@Slf4j(topic="请求ftp服务器")
public class FtpController { 

@Autowired
FtpConfig ftpConfig;
@GetMapping("/upload")
public String upload() { 

String fileName = "uploadfile.txt";
boolean result = FtpUtil.ftpUpload(fileName, ftpConfig.getUrl(),ftpConfig.getPort(),ftpConfig.getUsername(),
ftpConfig.getPassword(), ftpConfig.getLocalDir(), ftpConfig.getRemotePath());
if (result) { 

log.info("=======上传文件"+ fileName +"成功=======");
} else { 

log.info("=======上传文件"+ fileName +"失败=======");
}
return result?"上传成功":"上传失败";
}
@GetMapping("/download")
public String download(){ 

String fileName = "welcome.txt";
boolean result = FtpUtil.ftpDownload(fileName, ftpConfig.getUrl(),ftpConfig.getPort(),ftpConfig.getUsername(),
ftpConfig.getPassword(), ftpConfig.getRemotePath(), ftpConfig.getLocalDir() );
if (result) { 

log.info("=======下载文件"+ fileName +"成功=======");
} else { 

log.info("=======下载文件"+ fileName +"失败=======");
}
return result?"下载成功":"下载失败";
}
}

测试结果1： 上传成功

测试结果2： 下载成功

代码 github 地址：https://github.com/mmzsblog/springboot-FtpUtil