JFileTransfer

Universal file transfer abstraction library for Java. Provides a simple, unified API for reading files from SFTP, WebDAV, SMB/CIFS, FTP, and FTPS servers.

Features

• ✅ Unified API - Single interface for all file transfer protocols
• ✅ 4 Protocol Families - SFTP, WebDAV, SMB/CIFS, FTP/FTPS
• ✅ Builder Pattern - Fluent, type-safe configuration
• ✅ Optional Dependencies - Include only the protocols you need
• ✅ Thread-Safe - Concurrent read operations supported
• ✅ AutoCloseable - Proper resource management
• ✅ Minimal Dependencies - Java 11+, protocol libraries are optional

Quick Start

Maven Dependency

<dependency>
    <groupId>org.flossware</groupId>
    <artifactId>jfiletransfer</artifactId>
    <version>1.0</version>
</dependency>

<!-- Add protocol SDK (only include what you need) -->
<dependency>
    <groupId>com.github.mwiede</groupId>
    <artifactId>jsch</artifactId>
    <version>0.2.21</version>
</dependency>

Basic Usage

import org.flossware.filetransfer.FileTransferClient;
import org.flossware.filetransfer.SftpFileTransferClient;

// Create SFTP client
FileTransferClient client = SftpFileTransferClient.builder()
    .host("sftp.example.com")
    .port(22)
    .username("user")
    .password("secret")
    .basePath("/remote/files")
    .build();

// Read a file
byte[] data = client.readFile("document.pdf");

// Check if file exists
if (client.exists("report.xlsx")) {
    System.out.println("File exists!");
}

// List files
List<String> files = client.list("uploads/");

// Clean up
client.close();

Supported Protocols

SFTP (SSH File Transfer Protocol)

FileTransferClient sftp = SftpFileTransferClient.builder()
    .host("sftp.example.com")
    .port(22)
    .username("deploy")
    .password("secret")
    .basePath("/app/files")
    .build();

Password authentication:

.username("user")
.password("secret")

Private key authentication:

.username("deploy")
.privateKey("/home/user/.ssh/id_rsa")

Dependency:

<dependency>
    <groupId>com.github.mwiede</groupId>
    <artifactId>jsch</artifactId>
    <version>0.2.21</version>
</dependency>

WebDAV (Web Distributed Authoring and Versioning)

// Authenticated access
FileTransferClient webdav = WebDavFileTransferClient.builder()
    .baseUrl("https://webdav.example.com/files/")
    .username("user")
    .password("pass")
    .build();

// Anonymous access
FileTransferClient webdav = WebDavFileTransferClient.builder()
    .baseUrl("https://public.example.com/files/")
    .build();

Dependency:

<dependency>
    <groupId>com.github.lookfirst</groupId>
    <artifactId>sardine</artifactId>
    <version>5.13</version>
</dependency>

SMB/CIFS (Windows File Shares / Samba)

// Domain authentication
FileTransferClient smb = SmbFileTransferClient.builder()
    .server("smb://server.example.com/share/")
    .domain("CORP")
    .username("user")
    .password("pass")
    .build();

// Workgroup authentication
FileTransferClient smb = SmbFileTransferClient.builder()
    .server("smb://192.168.1.100/Public/")
    .username("guest")
    .password("")
    .build();

Dependency:

<dependency>
    <groupId>eu.agno3.jcifs</groupId>
    <artifactId>jcifs-ng</artifactId>
    <version>2.1.10</version>
</dependency>

FTP / FTPS (File Transfer Protocol)

// FTP
FileTransferClient ftp = FtpFileTransferClient.builder()
    .server("ftp://ftp.example.com/files/")
    .username("user")
    .password("pass")
    .build();

// FTPS (FTP over SSL/TLS)
FileTransferClient ftps = FtpFileTransferClient.builder()
    .server("ftps://secure.example.com/files/")
    .username("user")
    .password("pass")
    .build();

// Anonymous FTP
FileTransferClient ftp = FtpFileTransferClient.builder()
    .server("ftp://public.example.com/downloads/")
    .build();

Note: Uses Java's built-in FTP URL handler. Directory listing not supported.

API Reference

public interface FileTransferClient extends AutoCloseable {
    byte[] readFile(String path) throws IOException;
    InputStream openFile(String path) throws IOException;
    boolean exists(String path) throws IOException;
    List<String> list(String prefix) throws IOException;  // Not supported for FTP
    long getFileSize(String path) throws IOException;
    String getDescription();
    void close() throws IOException;
}

Common Use Cases

Backup & Sync

FileTransferClient source = SftpFileTransferClient.builder()
    .host("server1.example.com")
    .username("backup")
    .privateKey("/home/user/.ssh/backup_key")
    .basePath("/data")
    .build();

FileTransferClient destination = SmbFileTransferClient.builder()
    .server("smb://backup-server/backups/")
    .domain("CORP")
    .username("backup-service")
    .password("secret")
    .build();

// Copy file
byte[] data = source.readFile("important.dat");
// ... write to destination

File Migration

FileTransferClient oldServer = FtpFileTransferClient.builder()
    .server("ftp://old-server.com/files/")
    .username("migrate")
    .password("pass")
    .build();

FileTransferClient newServer = WebDavFileTransferClient.builder()
    .baseUrl("https://new-server.com/webdav/")
    .username("admin")
    .password("secret")
    .build();

List<String> files = oldServer.list("archive/");
for (String file : files) {
    byte[] data = oldServer.readFile(file);
    // ... write to new server
}

Deployment

FileTransferClient deployment = SftpFileTransferClient.builder()
    .host("prod-server.example.com")
    .username("deploy")
    .privateKey("/secrets/deploy_key")
    .basePath("/var/www/app")
    .build();

// Deploy artifacts
byte[] artifact = Files.readAllBytes(Paths.get("target/app.jar"));
// ... write via deployment client

Protocol Comparison

Protocol	Speed	Auth	Directory Listing	Best For
SFTP	⚡⚡⚡⚡	SSH Key/Password	✅ Yes	Secure file transfer, Linux/Unix servers
WebDAV	⚡⚡⚡	HTTP Basic/Digest	✅ Yes	HTTP-based, cloud storage (Nextcloud, OwnCloud)
SMB/CIFS	⚡⚡⚡⚡	NTLM/Domain	✅ Yes	Windows file shares, Samba servers
FTP	⚡⚡⚡	Username/Password	❌ No	Simple file transfer, public downloads
FTPS	⚡⚡⚡	Username/Password	❌ No	Secure FTP, legacy systems

Best Practices

1. Always use try-with-resources or close():

   try (FileTransferClient client = builder.build()) {
       byte[] data = client.readFile("file.txt");
   }

2. Use SFTP or FTPS for secure transfers:

   // Good - encrypted
   .server("ftps://secure.example.com/")
   
   // Bad - unencrypted
   .server("ftp://insecure.example.com/")

3. Prefer SSH keys over passwords for SFTP:

   // Better
   .privateKey("/home/user/.ssh/id_rsa")
   
   // Less secure
   .password("hardcoded-password")

4. Handle exceptions appropriately:

   try {
       byte[] data = client.readFile("file.txt");
   } catch (IOException e) {
       logger.error("Failed to read file", e);
   }

Versioning and Releases

This project uses X.Y semantic versioning (e.g., 1.0, 1.1, 2.0). Versions are automatically incremented on commits to the main branch and published to packagecloud.io.

Maven Repository

<repositories>
    <repository>
        <id>packagecloud-flossware</id>
        <url>https://packagecloud.io/flossware/java/maven2</url>
    </repository>
</repositories>

Building from Source

git clone https://github.com/FlossWare/jfiletransfer.git
cd jfiletransfer
mvn clean install

License

Apache License 2.0

Related Projects

• jcloudstorage - Cloud storage abstraction (S3, Azure, GCS, Google Drive, Dropbox, OneDrive)
• jmessaging - Messaging abstraction (Kafka, RabbitMQ, Redis)
• jcontainer - Container abstraction (Kubernetes, Docker, Hazelcast)
• jvcs - Version control abstraction (Git)
• jclassloader - Dynamic class loading from 34+ transport protocols