java实现sftp下载文件

以下是使用JSch库进行SFTP下载的Java示例代码：

import com.jcraft.jsch.*;

import java.io.*;

public class SFTPDownload {
    public static void main(String[] args) {
        String remoteFile = "/path/to/remote/file";
        String localFile = "/path/to/local/file";
        String username = "username";
        String password = "password";
        String host = "hostname";
        int port = 22;

        JSch jsch = new JSch();
        Session session = null;
        Channel channel = null;
        ChannelSftp channelSftp = null;

        try {
            session = jsch.getSession(username, host, port);
            session.setPassword(password);
            session.setConfig("StrictHostKeyChecking", "no");
            session.connect();

            channel = session.openChannel("sftp");
            channel.connect();
            channelSftp = (ChannelSftp) channel;

            channelSftp.get(remoteFile, new FileOutputStream(localFile));

        } catch (JSchException e) {
            e.printStackTrace();
        } catch (SftpException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            if (channelSftp != null) {
                channelSftp.disconnect();
            }
            if (channel != null) {
                channel.disconnect();
            }
            if (session != null) {
                session.disconnect();
            }
        }
    }
}

该示例代码使用JSch库连接到远程服务器，下载指定路径的文件到本地。需要替换示例代码中的`remoteFile`、`localFile`、`username`、`password`、`host`和`port`变量为实际的值。