通过JSch - Java实现的SFTP，jschjava实现sftp,JSch是Java Se

通过JSch - Java实现的SFTP，jschjava实现sftp,JSch是Java Se

JSch是Java Secure Channel的缩写。JSch是一个SSH2的纯Java实现。它允许你连接到一个SSH服务器，并且可以使用端口转发，X11转发，文件传输等，当然你也可以集成它的功能到你自己的应用程序。

本文只介绍如何使用JSch实现的SFTP功能。

SFTP是Secure File Transfer Protocol的缩写，安全文件传送协议。可以为传输文件提供一种安全的加密方法。SFTP 为 SSH的一部份，是一种传输文件到服务器的安全方式。SFTP是使用加密传输认证信息和传输的数据，所以，使用SFTP是非常安全的。但是，由于这种传输 方式使用了加密/解密技术，所以传输效率比普通的FTP要低得多，如果您对网络安全性要求更高时，可以使用SFTP代替FTP。（来自百度的解释）

要使用JSch，需要下载它的jar包，请从官网下载它：http://www.jcraft.com/jsch/

import java.io.FileNotFoundException;import java.io.OutputStream;import java.net.UnknownHostException;import java.util.Properties;import java.util.Vector;import org.apache.commons.httpclient.auth.AuthenticationException;import com.ebao.jewel.gs.integration.pub.CommonLog.exception.ExceptionUtil;import com.ebao.jewel.gs.integration.pub.CommonLog.utils.JewelIntLogUtils;import com.ebao.jewel.gs.integration.pub.commons.InterfaceUtil;import com.ebao.jewel.gs.integration.pub.connection.IConnection;import com.ebao.jewel.gs.integration.pub.constants.InterfaceConstants;import com.jcraft.jsch.ChannelSftp;import com.jcraft.jsch.JSch;import com.jcraft.jsch.JSchException;import com.jcraft.jsch.Session;public class JewelSftpClient implements IConnection {  private Session sshSession = null;  private ChannelSftp channelSftp = null;  private int connectTimes = 0;  public boolean connect(String host, int port, String username, String pwd)  throws Exception {    if (sshSession == null || !sshSession.isConnected()) {      JSch jsch = new JSch();      try {        sshSession = jsch.getSession(username, host, port);      } catch (JSchException je) {        // throw new Connection        throw je;      }    }    if (!sshSession.isConnected()) {      InterfaceUtil.batchLog("[TEST] sshSession.connect()");      sshSession.setPassword(pwd);      Properties sshConfig = new Properties();      sshConfig.put("StrictHostKeyChecking", "no");      sshSession.setConfig(sshConfig);      try {        sshSession.connect();      } catch (JSchException ex) {        if (ex.getMessage().indexOf("Session.connect") != -1) {          throw new UnknownHostException(ExceptionUtil.getExceptionMsg(ex));        } else {          throw new AuthenticationException(ExceptionUtil.getExceptionMsg(ex));        }      }    }    InterfaceUtil.batchLog("[TEST] sshSession has connected.");    try {      if (channelSftp == null || !channelSftp.isConnected()) {        InterfaceUtil.batchLog("[TEST] channelSftp.connect()");        channelSftp = (ChannelSftp) sshSession.openChannel("sftp");        channelSftp.connect();      }      InterfaceUtil.batchLog("[TEST] channelSftp has been established.");      return true;    } catch (JSchException je) {      if (connectTimes++ < InterfaceConstants.MAX_CONNECT_TIMES) {        String seq = connectTimes == 1 ? "1st" : connectTimes == 2            ? "2nd"            : connectTimes == 3 ? "3rd" : connectTimes + "st";        InterfaceUtil.batchLog("[TEST]" + seq            + " connection failed. Disconnected "            + (disconnect() == true ? "succeeded" : "failed"));        long sleepTime = InterfaceUtil.getConnectSleepTime() * 1000L;        Thread.sleep(sleepTime);        InterfaceUtil.batchLog("[TEST]" + sleepTime + " ms passed. Try "            + (int) (connectTimes + 1) + " connection.");        if (connectTimes == 4) {          InterfaceUtil              .batchLog("[TEST] !!!!!!!!!!!connection goes wrong!!!!!!!!!!!!!!!!");        }        return connect(host, port, username, pwd);      } else {        InterfaceUtil.batchLog("[TEST] connect excceeded 10 times.");        throw je;      }    }  }  public boolean disconnect() throws Exception {    try {      if (channelSftp != null &amp;&amp; channelSftp.isConnected()) {        channelSftp.disconnect();        InterfaceUtil.batchLog("[TEST] channelSftp has cloesd.");      }      if (sshSession != null &amp;&amp; sshSession.isConnected()) {        sshSession.disconnect();        InterfaceUtil.batchLog("[TEST] sshSession has cloesd.");      }      return true;    } catch (Exception e) {      return false;    }  }  public void upload(String src, String dst) throws Exception {    channelSftp.put(src, dst);  }  public void download(String src, String dst) throws Exception {    channelSftp.get(src, dst);  }  @SuppressWarnings("unchecked")  public Vector<Object> listFiles(String directory) throws Exception {    try {      channelSftp.cd(directory);    } catch (Exception e) {      throw new FileNotFoundException("No such file or directory.src:"          + directory);    }    Vector<Object> files = channelSftp.lsnames(directory);    return files;  }  public boolean moveFile(String src, String dst) throws Exception {    try {      channelSftp.rename(src, dst);      return true;    } catch (Exception e) {      JewelIntLogUtils.batchLog("[TEST] Move the file from " + src + " to "          + dst + " fail", e);      throw e;    }  }  public boolean isConnected() {    return channelSftp != null &amp;&amp; channelSftp.isConnected();  }  @Override  public void download(String src, OutputStream out) throws Exception {    channelSftp.get(src, out);  }}