java实现sftp服务器文件上传、下载、删除

首先是一个SftpClientUtil 类，封装了对sftp服务器文件上传、下载、删除的方法

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.Vector;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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;

public class SftpClientUtil {

 /**
 * 初始化日志引擎
 */
 private final Logger logger = LoggerFactory.getLogger(SftpClientUtil.class);

 /** Sftp */
 ChannelSftp sftp = null;
 /** 主机 */
    private String host = "";
    /** 端口 */
    private int port = 0;
    /** 用户名 */
    private String username = "";
    /** 密码 */
    private String password = "";
   
 /**
 * 构造函数
 *
 * @param host
 *            主机
 * @param port
 *            端口
 * @param username
 *            用户名
 * @param password
 *            密码
 *           
 */
    public SftpClientUtil(String host, int port, String username,
 String password){
   
        this.host = host;
        this.port = port;
        this.username = username;
        this.password = password;
    }

 /**
 * 连接sftp服务器
 *           
 * @throws Exception     
 */
 public void connect() throws Exception {

 JSch jsch = new JSch();
 Session sshSession = jsch.getSession(this.username, this.host, this.port);
 logger.debug(SftpClientUtil.class + "Session created.");

 sshSession.setPassword(password);
 Properties sshConfig = new Properties();
 sshConfig.put("StrictHostKeyChecking", "no");
 sshSession.setConfig(sshConfig);
 sshSession.connect(20000);
 logger.debug(SftpClientUtil.class + " Session connected.");

 logger.debug(SftpClientUtil.class + " Opening Channel.");
 Channel channel = sshSession.openChannel("sftp");
 channel.connect();
 this.sftp = (ChannelSftp) channel;
 logger.debug(SftpClientUtil.class + " Connected to " + this.host + ".");
 }

    /**
     * Disconnect with server
 *           
 * @throws Exception     
 */
    public void disconnect() throws Exception {
        if(this.sftp != null){
            if(this.sftp.isConnected()){
                this.sftp.disconnect();
            }else if(this.sftp.isClosed()){
            logger.debug(SftpClientUtil.class + " sftp is closed already");
            }
        }
    }

 /**
 * 上传单个文件
 *
 * @param directory
 *            上传的目录
 * @param uploadFile
 *            要上传的文件
 *           
 * @throws Exception     
 */
 public void upload(String directory, String uploadFile) throws Exception {
 this.sftp.cd(directory);
 File file = new File(uploadFile);
 this.sftp.put(new FileInputStream(file), file.getName());
 }

 /**
 * 上传目录下全部文件
 *
 * @param directory
 *            上传的目录
 *           
 * @throws Exception     
 */
 public void uploadByDirectory(String directory) throws Exception {

 String uploadFile = "";
 List<String> uploadFileList = this.listFiles(directory);
 Iterator<String> it = uploadFileList.iterator();

 while(it.hasNext())
 {
 uploadFile = it.next().toString();
 this.upload(directory, uploadFile);
 }
 }

 /**
 * 下载单个文件
 *
 * @param directory
 *            下载目录
 * @param downloadFile
 *            下载的文件
 * @param saveDirectory
 *            存在本地的路径
 *           
 * @throws Exception     
 */
 public void download(String directory, String downloadFile, String saveDirectory) throws Exception {
 String saveFile = saveDirectory + "//" + downloadFile;

 this.sftp.cd(directory);
 File file = new File(saveFile);
 this.sftp.get(downloadFile, new FileOutputStream(file));
 }

 /**
 * 下载目录下全部文件
 *
 * @param directory
 *            下载目录
 *           
 * @param saveDirectory
 *            存在本地的路径
 *           
 * @throws Exception     
 */
 public void downloadByDirectory(String directory, String saveDirectory) throws Exception {
 String downloadFile = "";
 List<String> downloadFileList = this.listFiles(directory);
 Iterator<String> it = downloadFileList.iterator();

 while(it.hasNext())
 {
 downloadFile = it.next().toString();
 if(downloadFile.toString().indexOf(".")<0){
 continue;
 }
 this.download(directory, downloadFile, saveDirectory);
 }
 }

 /**
 * 删除文件
 *
 * @param directory
 *            要删除文件所在目录
 * @param deleteFile
 *            要删除的文件
 *           
 * @throws Exception     
 */
 public void delete(String directory, String deleteFile) throws Exception {
 this.sftp.cd(directory);
 this.sftp.rm(deleteFile);
 }

 /**
 * 列出目录下的文件
 *
 * @param directory
 *            要列出的目录
 *           
 * @return list 文件名列表
 *
 * @throws Exception
 */
 @SuppressWarnings("unchecked")
 public List<String> listFiles(String directory) throws Exception {

 Vector fileList;
 List<String> fileNameList = new ArrayList<String>();

 fileList = this.sftp.ls(directory);
 Iterator it = fileList.iterator();

 while(it.hasNext())
 {
            String fileName = ((LsEntry)it.next()).getFilename();
            if(".".equals(fileName) || "..".equals(fileName)){
            continue;
            }
            fileNameList.add(fileName);

 }

 return fileNameList;
 }

 /**
 * 更改文件名
 *
 * @param directory
 *            文件所在目录
 * @param oldFileNm
 *            原文件名
 * @param newFileNm
 *            新文件名
 *           
 * @throws Exception     
 */
 public void rename(String directory, String oldFileNm, String newFileNm) throws Exception {
 this.sftp.cd(directory);
 this.sftp.rename(oldFileNm, newFileNm);
 }

 public void cd(String directory)throws Exception {
 this.sftp.cd(directory);
 }
 public InputStream get(String directory) throws Exception{
 InputStream streatm=this.sftp.get(directory);
 return streatm;
 }
}

其次是供jsp调用的的servlet类

public class DownloadApplyPersonServlet extends HttpServlet {

 /** 初始化日志引擎 * */
 private final Logger logger = LoggerFactory
 .getLogger(DownloadApplyPersonServlet.class);

 public void doGet(HttpServletRequest request, HttpServletResponse response)
 throws IOException, ServletException {
 doPost(request, response);
 }

 // 在doPost()方法中，当servlet收到浏览器发出的Post请求后，实现文件下载
 public void doPost(HttpServletRequest request, HttpServletResponse response)
 throws IOException, ServletException {
 logger.info("进入下载文件开始..........");
 String host="";//主机地址
 String port="";//主机端口
 String username="";//服务器用户名
 String password ="";//服务器密码
 String planPath ="";//文件所在服务器路径
 BufferedInputStream bis = null;
 BufferedOutputStream bos = null;
 OutputStream fos = null;

 String fileName = "KJ_CUST_KBYJ";//KJ_CUST_KBYJ20140326.txt
 SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd");
 String currentDate =   formatter.format(new Date());
 String downloadFile = fileName + currentDate + ".zip";

 PrintWriter out=null;
 SftpClientUtil sftp = new SftpClientUtil(host, Integer.parseInt(port), username,
 password);
 try {
 sftp.connect();
 String filename="";
// String[] strs=planUrl.split("/");
 String filePath=planPath;
 //列出目录下的文件
 List<String> listFiles=sftp.listFiles(filePath);
 boolean isExists=listFiles.contains(downloadFile);
 if(isExists){
 sftp.cd(filePath);
 if(sftp.get(downloadFile)!=null){
 bis = new BufferedInputStream(sftp.get(downloadFile));
 }
 filename=downloadFile;
 fos = response.getOutputStream();
 bos = new BufferedOutputStream(fos);
 response.setCharacterEncoding("UTF-8");
 response.setContentType("application/x-msdownload;charset=utf-8");
 final String agent = request.getHeader("User-Agent");
 String attachment = "attachment;fileName=";
 String outputFilename = null;

 if (agent.indexOf("Firefox") > 0) {
 attachment = "attachment;fileName*=";
 outputFilename = "=?UTF-8?B?" + (new String(Base64.encodeBase64(filename.getBytes("UTF-8")))) + "?=";;
 } else {
 if (agent.indexOf("MSIE") != -1) {
 outputFilename = new String(filename.getBytes("gbk"), "iso8859-1");
         } else {
 outputFilename = new String(filename.getBytes("UTF-8"), "iso8859-1");
         }
 }
 response.setHeader("Content-Disposition", attachment + outputFilename);
 int bytesRead = 0;
 //输入流进行先读，然后用输出流去写，下面用的是缓冲输入输出流
 byte[] buffer = new byte[8192];
 while ((bytesRead = bis.read(buffer)) != -1) {
 bos.write(buffer,0,bytesRead);
 }
 bos.flush();
 logger.info("文件下载成功");
 }else{
 response.setCharacterEncoding("utf-8");          
     response.setContentType("text/html; charset=UTF-8");
     out=response.getWriter();
 out.println("<html >" +
 "<body>" +
 "没有找到你要下载的文件" +
 "</body>" +
 "</html>");
 }
 } catch (Exception e) {
 response.setCharacterEncoding("utf-8");          
     response.setContentType("text/html; charset=UTF-8");
     out=response.getWriter();
 out.println("<html >" +
 "<body>" +
 "没有找到你要下载的文件" +
 "</body>" +
 "</html>");
 }finally{
 try {
 sftp.disconnect();
 logger.info("SFTP连接已断开");
 } catch (Exception e) {
 e.printStackTrace();
 }

 if(out!=null){
 out.close();
 }
 logger.info("out已关闭");
 if(bis != null){
 bis.close();
 }
 logger.info("bis已关闭");
 if(bos != null){
 bos.close();
 }
 logger.info("bos已关闭");
 }
 }
}

最后是对servlet的配置，具体可参考web.xml中servlet的配置。