java中sftp文件上传与下载

Java中使用sftp进行文件上传与下载

最近项目中使用sftp进行文件上传与下载，特意写一篇文章用来作为例子参考：
注：项目的pom文件里面需要加上依赖包：

<dependency>
            <groupId>com.jcraft</groupId>
            <artifactId>jsch</artifactId>
            <version>0.1.51</version>
</dependency>

package com.leo.common.util;

import java.io.File;
import java.io.InputStream;
import java.util.Map;
import java.util.Properties;
import java.util.Vector;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.ChannelSftp.LsEntry;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.SftpATTRS;
import com.jcraft.jsch.SftpException;
import com.leo.common.logger.LoggerUtil;
import com.leo.common.logger.LoggerUtil.Level;

public class SFtpApload {
    /**
    * url 服务器地址
    * port 端口号
    * username 服务器用户名
    * password 服务器密码
    * path 上传文件在服务器上的路径
    * filename 上传的文件名称
    * input 待上传内容的流
    */
    public static boolean uploadFile(String url, int port, String username,
            String password, String path, String filename, InputStream input) {
        try {
            ChannelSftp sftp = connect(url, port, username, password);
            upload(sftp, path, filename, input);
            disconnect(sftp);
        } catch (Exception e) {
            LoggerUtil.log(Level.ERROR, e, "upload file failed file={0}",
                    filename);
            return false;
        }
        LoggerUtil.log(Level.DEBUG, "upload file success file={0}", filename);
        return true;
    }


    public static boolean downloadFile(String url, int port, String username,
            String password, String remotePath, String localPath,
            String folderName, Map<String, Integer> lastModifiedDatesBefore) {
        boolean flag = true;
        try {
            ChannelSftp sftp = connect(url, port, username, password);// 连接sftp服务器
            flag = download(remotePath, localPath, folderName, sftp,
                    lastModifiedDatesBefore);
            disconnect(sftp);
        } catch (Exception e) {
            LoggerUtil.log(Level.ERROR, e, "download file failed={0}",
                    folderName);
            return false;
        }
        if (flag) {
            LoggerUtil
                    .log(Level.DEBUG, "download file success={0}", folderName);
        }

        return flag;
    }

    /**
     * 下载指定文件夹的txt文件
     *
     * 0.获取文件夹下所有文件：ls 1.获取文件属性 SftpATTRS getMTime() 2.判断修改时间： a.获取本地文件修改时间
     * b.时间晚于本地时间则下载，返回 c.时间早于本地时间则不下载，返回
     *
     * @param remotePath
     * @param localPath
     * @param fileName
     * @param sftp
     * @param ftpDate
     * @throws Exception
     */
    @SuppressWarnings("unchecked")
    public static boolean download(String remotePath, String localPath,
            String folderName, ChannelSftp sftp,
            Map<String, Integer> lastModifiedDatesBefore) throws Exception {
        Vector<LsEntry> files = null;
        try {
            files = sftp.ls(remotePath + folderName);
        } catch (Exception e) {
            LoggerUtil.log(Level.ERROR, "{0} is not exist;", folderName);
            return false;
        }
        if (files.size() <= 0) {
            return false;
        }
        for (LsEntry file : files) {

            String fileName = file.getFilename();
            if (fileName.endsWith(".txt")) {
                File localFile = new File(localPath + folderName + "/"
                        + fileName);
                if (!localFile.exists()) {// 判断本地文件是否存在
                    localFile.getParentFile().mkdirs();
                    localFile.createNewFile();
                }
                SftpATTRS sa = sftp.lstat(remotePath + folderName + "/"
                        + fileName);// 获取服务器文件属性信息
                int time = sa.getMTime();// 获取服务器上文件最近修改时间
                int oldTime = lastModifiedDatesBefore.get(fileName.substring(6)) == null ? 0
                        : lastModifiedDatesBefore.get(fileName.substring(6));// 获取本地文件最新修改时间
                if (oldTime == 0 || time > oldTime) {
                    sftp.cd(remotePath + folderName);
                    sftp.get(fileName, localFile.getAbsolutePath());// 下载文件
                    lastModifiedDatesBefore.put(fileName.substring(6), time);
                }
            } else {
                continue;
            }

        }
        return true;

    }

    private static ChannelSftp connect(String host, int port, String username,
            String password) throws Exception {
        JSch jsch = new JSch();
        jsch.getSession(username, host, port);
        Session sshSession = jsch.getSession(username, host, port);
        sshSession.setPassword(password);
        Properties sshConfig = new Properties();
        sshConfig.put("StrictHostKeyChecking", "no");
        sshSession.setConfig(sshConfig);
        sshSession.connect();
        Channel channel = sshSession.openChannel("sftp");
        channel.connect();
        return (ChannelSftp) channel;
    }

    /**
     * Disconnect with server
     */
    private static void disconnect(ChannelSftp sftp) {
        if (sftp != null) {
            if (sftp.isConnected()) {
                sftp.disconnect();
            } else if (sftp.isClosed()) {
                LoggerUtil.log(Level.WARN, "sftp is closed already");
            }
        }

    }

    /**
     * upload all the files to the server
     *
     * @throws SftpException
     */
    private static void upload(ChannelSftp sftp, String path, String filename,
            InputStream input) throws SftpException {
        createDir(path, sftp);
        sftp.put(input, filename);
    }

    /**
     * create Directory
     *
     * @param filepath
     * @param sftp
     * @throws SftpException
     */
    private static void createDir(String filepath, ChannelSftp sftp)
            throws SftpException {
        try {
            sftp.cd(filepath);
        } catch (SftpException e) {
            try {
                sftp.mkdir(filepath);
            } catch (SftpException e1) {
            }
            sftp.cd(filepath);
        }

    }

}

LoggerUtil日志类的代码如下：

package com.leo.common.ftp;

import java.text.MessageFormat;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.leo.common.validate.YDStringUtils;
/**
 * 日志操作类
 * @author huagong
 *
 */
public final class LoggerUtil {
    final static Log logger = LogFactory.getLog(Object.class);

    public enum Level {
        DEBUG, INFO, WRAN, WARN, ERROR;
    }

    public static void log(Level level, String message, Object... params) {
        if (isBlank(message)) {
            message = "{0}";
        }
        String paramObject = MessageFormat.format(message, params);
        switch (level) {
        case DEBUG:
            if (logger.isDebugEnabled())
                logger.debug(paramObject);
            break;
        case INFO:
            if (logger.isInfoEnabled())
                logger.info(paramObject);
            break;
        case WARN:
        case WRAN:
            if (logger.isWarnEnabled())
                logger.warn(paramObject);
            break;
        case ERROR:
            if (logger.isErrorEnabled())
                logger.error(paramObject);
            break;
        default:
            break;
        }

    }

    public static void log(Level level, Throwable paramThrowable, String message, Object... params) {
        if (isBlank(message)) {
            message = "{0}";
        }
        String paramObject = MessageFormat.format(message, params);
        switch (level) {
        case DEBUG:
            if (logger.isDebugEnabled())
                logger.debug(paramObject, paramThrowable);
            break;
        case INFO:
            if (logger.isInfoEnabled())
                logger.info(paramObject, paramThrowable);
            break;
        case WARN:
        case WRAN:
            if (logger.isWarnEnabled())
                logger.warn(paramObject, paramThrowable);
            break;
        case ERROR:
            if (logger.isErrorEnabled())
                logger.error(paramObject, paramThrowable);
            break;
        default:
            break;
        }
    }
    /**
     * 判断null字符串
     * @param value
     * @return
     */
    public static boolean isBlank(String value) {
        if (value == null || "null".equalsIgnoreCase(value)) {
            return true;
        }
        if (org.apache.commons.lang.StringUtils.isBlank(value)) {
            return true;
        }
        return false;
    }

}