java ftp文件上传

你可以使用Java中提供的FTPClient类来实现FTP文件上传，具体步骤如下：

1. 创建FTPClient对象并连接FTP服务器

FTPClient ftpClient = new FTPClient();
ftpClient.connect(ftpServer, port);
ftpClient.login(username, password);

2. 设置上传文件的类型为二进制

ftpClient.setFileType(FTP.BINARY_FILE_TYPE);

3. 切换到上传文件的目录

ftpClient.changeWorkingDirectory(remoteDirectory);

4. 上传文件

File file = new File(localFilePath);
InputStream inputStream = new FileInputStream(file);
ftpClient.storeFile(remoteFileName, inputStream);
inputStream.close();

5. 关闭连接

ftpClient.logout();
ftpClient.disconnect();

完整的代码如下：

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;

public class FTPFileUploadDemo {
    public static void main(String[] args) throws IOException {
        String ftpServer = "ftp.example.com";
        int port = 21;
        String username = "username";
        String password = "password";
        String remoteDirectory = "/remote/directory";
        String remoteFileName = "remote_file_name";
        String localFilePath = "local_file_path";

        FTPClient ftpClient = new FTPClient();
        ftpClient.connect(ftpServer, port);
        ftpClient.login(username, password);
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
        ftpClient.changeWorkingDirectory(remoteDirectory);

        File file = new File(localFilePath);
        InputStream inputStream = new FileInputStream(file);
        ftpClient.storeFile(remoteFileName, inputStream);
        inputStream.close();

        ftpClient.logout();
        ftpClient.disconnect();
    }
}

注意，这里使用了Apache Commons Net库中的FTPClient类，需要添加相关依赖。