springboot整合ftp服务器实现上传与下载

1. 添加依赖

在项目的pom.xml文件中添加spring-boot-starter-web和commons-net的依赖：

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>commons-net</groupId><artifactId>commons-net</artifactId><version>3.8.0</version></dependency>
</dependencies>

2. 配置FTP连接信息

在application.properties或application.yml文件中配置FTP服务器的地址、端口、用户名和密码：

ftp.host=ftp.example.com
ftp.port=21
ftp.username=your_username
ftp.password=your_password

3. 创建FTP工具类

创建一个名为FtpUtil的工具类，用于封装FTP操作的方法：

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;public class FtpUtil {private static FTPClient ftpClient = new FTPClient();public static void connect(String host, int port, String username, String password) throws IOException {ftpClient.connect(host, port);int replyCode = ftpClient.getReplyCode();if (!FTPReply.isPositiveCompletion(replyCode)) {ftpClient.disconnect();throw new IOException("FTP server refused connection");}boolean success = ftpClient.login(username, password);if (!success) {ftpClient.logout();throw new IOException("FTP login failed");}}public static void disconnect() {if (ftpClient.isConnected()) {try {ftpClient.logout();ftpClient.disconnect();} catch (IOException e) {e.printStackTrace();}}}public static List<String> listFiles(String directory) throws IOException {List<String> fileNames = new ArrayList<>();ftpClient.changeWorkingDirectory(directory);String[] names = ftpClient.listNames();for (String name : names) {fileNames.add(name);}return fileNames;}public static void uploadFile(String localFilePath, String remoteFilePath) throws IOException {InputStream inputStream = new FileInputStream(localFilePath);boolean done = ftpClient.storeFile(remoteFilePath, inputStream);inputStream.close();if (!done) {throw new IOException("File upload failed");}}public static void downloadFile(String remoteFilePath, String localFilePath) throws IOException {InputStream inputStream = ftpClient.retrieveFileStream(remoteFilePath);FileOutputStream outputStream = new FileOutputStream(localFilePath);byte[] buffer = new byte[1024];int bytesRead;while ((bytesRead = inputStream.read(buffer)) != -1) {outputStream.write(buffer, 0, bytesRead);}inputStream.close();outputStream.close();}
}

4. 使用FTP工具类进行文件上传和下载操作

在需要使用FTP的地方，调用FtpUtil类的方法进行文件上传和下载操作。例如：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;@Service
public class FtpService {@Autowiredprivate FtpUtil ftpUtil;public void uploadFile(MultipartFile file, String remoteDirectory) throws IOException {String localFilePath = file.getOriginalFilename();String remoteFilePath = remoteDirectory + "/" + file.getOriginalFilename();ftpUtil.uploadFile(localFilePath, remoteFilePath);}public void downloadFile(String remoteFilePath, String localDirectory) throws IOException {String localFilePath = localDirectory + "/" + Paths.get(remoteFilePath).getFileName().toString();ftpUtil.downloadFile(remoteFilePath, localFilePath);}
}

5. 在Controller中使用FtpService进行文件上传和下载操作

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;@RestController
@RequestMapping("/ftp")
public class FtpController {@Autowiredprivate FtpService ftpService;@PostMapping("/upload")public ResponseEntity<String> uploadFile(@RequestParam("file") MultipartFile file, @RequestParam("directory") String directory) throws IOException {ftpService.uploadFile(file, directory);return new ResponseEntity<>("File uploaded successfully", HttpStatus.OK);}@GetMapping("/download/{filename}")public ResponseEntity<byte[]> downloadFile(@PathVariable("filename") String filename) throws IOException {byte[] fileData = ftpService.downloadFile(filename);return new ResponseEntity<>(fileData, HttpStatus.OK);}
}