SFTP第二篇——jsch实现sftp上传下载等功能

一、导入依赖

     com.jcraft
     jsch
     0.1.54

二、sftp.properties配置信息文件

sftp.client.protocol=sftp
sftp.client.host=localhost
sftp.client.port=22
sftp.client.username=kungfupanda
sftp.client.password=xxxxx
sftp.client.root=/Users/kungfupanda
sftp.client.privateKey=
sftp.client.passphrase=
sftp.client.sessionStrictHostKeyChecking=no
sftp.client.sessionConnectTimeout=15000
sftp.client.channelConnectedTimeout=15000
sftp.client.localPath=./_files

按照第一篇所说，创建sftp server。这里是连接到本地mac的sftp server，而嵌入式的sftp server一般用来测试。

三、SftpProperties配置类

@Data
@Component
@PropertySource(value = "classpath:sftp.properties")
public class SftpProperties {

    @Value("${sftp.client.host}")
    private String host;

    @Value("${sftp.client.port}")
    private Integer port;

    @Value("${sftp.client.protocol}")
    private String protocol;

    @Value("${sftp.client.username}")
    private String username;

    @Value("${sftp.client.password}")
    private String password;

    @Value("${sftp.client.root}")
    private String root;

    @Value("${sftp.client.privateKey}")
    private String privateKey;

    @Value("${sftp.client.passphrase}")
    private String passphrase;

    @Value("${sftp.client.sessionStrictHostKeyChecking}")
    private String sessionStrictHostKeyChecking;

    @Value("${sftp.client.sessionConnectTimeout}")

    private Integer sessionConnectTimeout;

    @Value("${sftp.client.channelConnectedTimeout}")
    private Integer channelConnectedTimeout;

    @Value("${sftp.client.localPath}")
    private  String localPath;
}

这里将外部配置信息加载到类中。

四、SftpUtils类

@Slf4j
@Component
public class SftpUtils {

    // set first login prompt : ask, yes, no
    private static final String STRICT_HOST_KEY_CHECKING = "StrictHostKeyChecking";
    @Autowired
    private SftpProperties sftpProperties;

    public File downloadFile(String src, String dst, int mode) throws JSchException {
        ChannelSftp sftp = this.createSftp();
        try {
            sftp.cd(sftpProperties.getRoot());
            log.info("Change path to " + sftpProperties.getRoot());

            File file = new File(dst);
            sftp.get(src, dst, new CddSftpProgressMonitor(), mode);
            log.info("Download file success. TargetPath: " + src);
            return file;
        } catch (SftpException e) {
            log.error("SftpException:", e);
            throw new BatchProcessingException("SftpException");
        } catch (Exception e) {
            log.error("Download file failure. TargetPath: " + src, e);
            throw new BatchProcessingException("Download File failure");
        } finally {
            this.disconnect(sftp);
        }
    }

    public ChannelSftp createSftp() throws JSchException {
        JSch jsch = new JSch();
        Boolean boo = StringUtils.isNotBlank(sftpProperties.getPrivateKey());
        if (boo) {
            if (StringUtils.isNotBlank(sftpProperties.getPassphrase())) {
                jsch.addIdentity(sftpProperties.getPrivateKey(), sftpProperties.getPassphrase());
            } else {
                jsch.addIdentity(sftpProperties.getPrivateKey());
            }
        }
        log.info("Try to connect sftp[" + sftpProperties.getUsername() + "@" + sftpProperties.getHost() + "], use password[" + sftpProperties.getPassword() + "]");

        Session session = createSession(jsch, sftpProperties.getHost(), sftpProperties.getUsername(), sftpProperties.getPort());
        if (!boo) {
            session.setPassword(sftpProperties.getPassword());
        }
        session.connect(sftpProperties.getSessionConnectTimeout());

        log.info("Session connected to [" + sftpProperties.getHost() + "]");

        Channel channel = session.openChannel(sftpProperties.getProtocol());
        channel.connect(sftpProperties.getChannelConnectedTimeout());

        log.info("Channel created to [" + sftpProperties.getHost() + "]");

        return (ChannelSftp) channel;
    }

    private Session createSession(JSch jsch, String host, String username, Integer port) throws JSchException {
        Session session = port <= 0 ? jsch.getSession(username, host) : jsch.getSession(username, host, port);
        if (session == null) {
            throw new BatchProcessingException(host + " session is null");
        }
        session.setConfig(STRICT_HOST_KEY_CHECKING, sftpProperties.getSessionStrictHostKeyChecking());
        return session;
    }

    private void disconnect(ChannelSftp sftp) {
        try {
            if (sftp != null) {
                if (sftp.isConnected()) {
                    sftp.disconnect();
                } else if (sftp.isClosed()) {
                    log.info("sftp is closed already");
                }
                if (sftp.getSession() != null) {
                    sftp.getSession().disconnect();
                }
            }
        } catch (JSchException e) {
            log.error("disconnect failure", e);
        }
    }
}

jsch是通过ChannelSftp来进行具体操作的，比如上传下载等。

五、SftpProgressMonitor监控类

@Slf4j
public class CddSftpProgressMonitor implements SftpProgressMonitor {
    private long count = 0;     //当前接收的总字节数
    private long max = 0;       //最终文件大小
    private long percent = -1;  //进度

    @Override
    public boolean count(long count) {
        this.count += count;
        if (percent >= this.count * 100 / max) {
            return true;
        }
        percent = this.count * 100 / max;
        log.info("Completed " + this.count + "(" + percent + "%) out of " + max + ".");
        return true;
    }

    @Override
    public void init(int op, String src, String dest, long max) {
        if (op == SftpProgressMonitor.PUT) {
            log.info("Upload file begin.");
        } else {
            log.info("Download file begin.");
        }
        this.max = max;
        this.count = 0;
        this.percent = -1;
    }

    @Override
    public void end() {
        log.info("Transferring done.");
    }
}

通过实现SftpProgressMonitor来监控文件下载进度等。