java上传ftp文件代码

以下是一个简单的Java上传文件到FTP服务器的示例代码：

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import java.io.*;

public class FTPUploader {
    public static void main(String[] args) {
        String server = "ftp.example.com";
        int port = 21;
        String user = "ftp_username";
        String password = "ftp_password";
        String remoteDir = "/upload";
        String localFilePath = "/path/to/local/file.txt";
        String remoteFileName = "file.txt";
        
        FTPClient ftpClient = new FTPClient();
        try {
            ftpClient.connect(server, port);
            ftpClient.login(user, password);
            ftpClient.enterLocalPassiveMode();
            ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
            
            File localFile = new File(localFilePath);
            InputStream inputStream = new FileInputStream(localFile);
            
            ftpClient.changeWorkingDirectory(remoteDir);
            boolean uploaded = ftpClient.storeFile(remoteFileName, inputStream);
            
            inputStream.close();
            ftpClient.logout();
            ftpClient.disconnect();
            
            if (uploaded) {
                System.out.println("File uploaded successfully.");
            } else {
                System.out.println("File upload failed.");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

需要注意的是，需要使用Apache Commons Net库来实现FTP客户端功能。此外，需要根据实际情况修改服务器地址、端口、用户名、密码、远程目录、本地文件路径以及远程文件名等参数。