文件上传（二） 搭建 xftp 服务器，并实现上传工具类

package com.taotao.common.utils;

import com.jcraft.jsch.*;
import com.taotao.common.pojo.R;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileInputStream;
import java.lang.reflect.Array;
import java.util.*;

public class FtpUtils {
    private static final Logger LOG = LoggerFactory.getLogger(FtpUtils.class);

    private ChannelSftp sftp;
    private Session session;
    private Channel channel;

    private void init() {
        String host = "xxxx";
        int port = 22;
        String username = "xxx";
        String passwd = "xxx";
        // 若文件存在
        session = getSession(host, port, username, passwd);
        channel = getChannel(session);
        sftp = (ChannelSftp) channel;
    }

    private void close() {
        closeAll(); //关闭连接
    }

    /**
     * upload
     * @param fileName 上传的文件 C:/img/0.jpg
     * @return
     */
    public R upload(String fileName) {
        File file = new File(fileName);
        if ( !file.exists()) {
            return R.error("上传的文件不存在！");
        }

        String uploadMapping = "/home/ftpuser/img/";
        init();
        String upload = uploadFile(uploadMapping,file);
        close(); //关闭连接

        // 构建返回参数
        Map<String, String> data = new HashMap<String, String>();
        data.put("url", uploadMapping+file.getName());
        return R.success(upload, data);
    }

    /**
     * 下载文件
     *
     * @param directory
     *            下载目录
     * @param downloadFile
     *            下载的文件
     * @param saveFile
     *            存在本地的路径
     */
    public R download(String directory, String downloadFile,
                      String saveFile) {
        init();
        try {
            sftp.cd(directory);
            sftp.get(downloadFile, saveFile);
            return R.success("下载成功！");
        } catch (Exception e) {
            System.out.println(e);
            return R.success("下载失败！");
        } finally {
            close();
        }
    }

    public Channel getChannel(Session session) {
        Channel channel = null;
        try {
            channel = session.openChannel("sftp");
            channel.connect();
            LOG.info("get Channel success!");
        } catch (JSchException e) {
            LOG.info("get Channel fail!", e);
        }
        return channel;
    }

    public Session getSession(String host, int port, String username,
                              final String password) {
        Session session = null;
        try {
            JSch jsch = new JSch();
            jsch.getSession(username, host, port);
            session = jsch.getSession(username, host, port);
            session.setPassword(password);
            Properties sshConfig = new Properties();
            sshConfig.put("StrictHostKeyChecking", "no");
            session.setConfig(sshConfig);
            session.connect();
            LOG.info("Session connected!");
        } catch (JSchException e) {
            LOG.info("get Channel failed!", e);
        }
        return session;
    }

    /**
     * @param
     * @param remoteDir
     *            上传目录
     * @param file
     *            上传文件
     * @return
     */
    public String uploadFile(String remoteDir, File file) {
        String result = "";
        try {
            String[] folders = remoteDir.split( "/" );
            ArrayList<String> lists = new ArrayList<>();
            for (String folder : folders) {
                lists.add(folder);
            }
            try {
                sftp.cd( "/" );
                sftp.cd( remoteDir );
            }
            catch ( SftpException e ) {
                System.out.println("error!!!!! e = " + e);
                // 若进入失败，则调用安全进入目录的方法，此时目录没有则会被创建
                safeCDRemoteDir("", 0, lists);
            }
            if (file != null) {
                sftp.put(new FileInputStream(file), file.getName());
                result = "上传成功！";
            } else {
                result = "文件为空！不能上传！";
            }
        } catch (Exception e) {
            LOG.info("上传失败！", e);
            result = "上传失败！";
        }
        return result;
    }

    /**
     * 删除文件
     *
     * @param directory
     *            要删除文件所在目录
     * @param deleteFile
     *            要删除的文件
     * @param sftp
     */
    public String delete(String directory, String deleteFile, ChannelSftp sftp) {
        String result = "";
        try {
            sftp.cd(directory);
            sftp.rm(deleteFile);
            result = "删除成功！";
        } catch (Exception e) {
            result = "删除失败！";
            LOG.info("删除失败！", e);
        }
        return result;
    }

    private void closeChannel(Channel channel) {
        if (channel != null) {
            if (channel.isConnected()) {
                channel.disconnect();
            }
        }
    }

    private void closeSession(Session session) {
        if (session != null) {
            if (session.isConnected()) {
                session.disconnect();
            }
        }
    }

    public void closeAll() {
        try {
            closeChannel(sftp);
            closeChannel(channel);
            closeSession(session);
        } catch (Exception e) {
            LOG.info("closeAll", e);
        }
    }

    public int safeCDRemoteDir(String currPath, int index, ArrayList<String> pathList) throws SftpException {
        int size = pathList.size();
        for (int i=index; i < size; i++) {
            System.out.println(pathList.get(i));
            if (pathList.get(i).length() > 0) {
                try {
                    // 逐层进入
                    sftp.cd( pathList.get(i) );
                    // 若成功，则更改当前路径
                    currPath += "/" + pathList.get(i);
                }
                catch ( SftpException e ) {
                    // 创建对应的目录
                    sftp.mkdir( currPath + "/" + pathList.get(i));
                    System.out.println(pathList.toString());
                    return safeCDRemoteDir(currPath,i,pathList);
                }
            }
        }
        return 1;
    }
}