sftp 定时下载一个目录下所有文件并删除原目录下文件 java 实现

你可以使用 JSch 库实现 SFTP 客户端，并使用定时任务框架（如 Quartz）实现定时任务。具体实现步骤如下：

1. 引入 JSch 库，可以通过 Maven 或 Gradle 进行引入，或者手动下载并导入。

2. 使用 JSch 创建 SFTP 客户端连接，连接代码如下：

JSch jsch = new JSch();
Session session = jsch.getSession(username, host, port);
session.setPassword(password);
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
ChannelSftp channel = (ChannelSftp) session.openChannel("sftp");
channel.connect();

3. 使用 `channel.ls()` 方法获取指定目录下的所有文件，并使用 `channel.get()` 方法下载文件，下载代码如下：

List<ChannelSftp.LsEntry> fileList = channel.ls(remotePath);
for (ChannelSftp.LsEntry file : fileList) {
    if (!file.getAttrs().isDir()) {
        String remoteFile = remotePath + "/" + file.getFilename();
        String localFile = localPath + "/" + file.getFilename();
        channel.get(remoteFile, localFile);
    }
}

4. 将下载完成的文件从 SFTP 服务器上删除，删除代码如下：

for (ChannelSftp.LsEntry file : fileList) {
    if (!file.getAttrs().isDir()) {
        String remoteFile = remotePath + "/" + file.getFilename();
        channel.rm(remoteFile);
    }
}

5. 将以上代码封装成一个方法，并使用定时任务框架定时调用即可。完整代码如下：

public class SftpDownloadTask {

    private String host;
    private int port;
    private String username;
    private String password;
    private String remotePath;
    private String localPath;

    public void run() throws JSchException, SftpException {
        JSch jsch = new JSch();
        Session session = jsch.getSession(username, host, port);
        session.setPassword(password);
        Properties config = new Properties();
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        session.connect();
        ChannelSftp channel = (ChannelSftp) session.openChannel("sftp");
        channel.connect();

        List<ChannelSftp.LsEntry> fileList = channel.ls(remotePath);
        for (ChannelSftp.LsEntry file : fileList) {
            if (!file.getAttrs().isDir()) {
                String remoteFile = remotePath + "/" + file.getFilename();
                String localFile = localPath + "/" + file.getFilename();
                channel.get(remoteFile, localFile);
            }
        }

        for (ChannelSftp.LsEntry file : fileList) {
            if (!file.getAttrs().isDir()) {
                String remoteFile = remotePath + "/" + file.getFilename();
                channel.rm(remoteFile);
            }
        }

        channel.disconnect();
        session.disconnect();
    }

    public static void main(String[] args) throws SchedulerException {
        SchedulerFactory schedulerFactory = new StdSchedulerFactory();
        Scheduler scheduler = schedulerFactory.getScheduler();
        JobDetail jobDetail = JobBuilder.newJob(SftpDownloadJob.class)
                .withIdentity("SftpDownloadJob", "SftpDownloadGroup")
                .build();
        Trigger trigger = TriggerBuilder.newTrigger()
                .withIdentity("SftpDownloadTrigger", "SftpDownloadGroup")
                .withSchedule(CronScheduleBuilder.cronSchedule("0 0 0 * * ?")) // 每天 0 点运行
                .build();
        scheduler.scheduleJob(jobDetail, trigger);
        scheduler.start();
    }

    public static class SftpDownloadJob implements Job {
        @Override
        public void execute(JobExecutionContext context) throws JobExecutionException {
            SftpDownloadTask task = new SftpDownloadTask();
            task.host = "sftp.example.com";
            task.port = 22;
            task.username = "username";
            task.password = "password";
            task.remotePath = "/remote/path";
            task.localPath = "/local/path";
            try {
                task.run();
            } catch (JSchException | SftpException e) {
                throw new JobExecutionException(e);
            }
        }
    }

}