JSCH通过sftp下载文件

使用jsch通过ftps连接服务器端下载文件
Session session=jsch.getSession(ftpUserName, ftpHost, ftpPort);
session.setPassword(ftpPassword);
session.connect();
ChannelSftp channel = (ChannelSftp) session.openChannel(“sftp”);
获取到channel通过ChannelSftp 的相关方法上传或是下载文件
channel.get(remoteFile, output);
channel.put(input, newName);
使用完成后关闭session,关闭channel
channel.disconnect();
session.disconnect();

程序代码：

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Vector;

import org.apache.log4j.Logger;

import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.SftpException;

public class SFTPProcessor {
private static Session session = null;
private static ChannelSftp channel = null;
private static Logger logger = Logger.getLogger(SFTPProcessor.class);



public static ChannelSftp getConnect() {
        String ftpHost = SysPropUtil.getValue("download.host");
          String port = SysPropUtil.getValue("download.port");
          String ftpUserName = SysPropUtil.getValue("download.username");
          String ftpPassword = SysPropUtil.getValue("download.pass");
//默认的端口22 此处我是定义到常量类中；
int ftpPort = 22;
//判断端口号是否为空，如果不为空，则赋值
if (port != null && !port.equals("")) {
              ftpPort = Integer.valueOf(port);
          }
          JSch jsch = new JSch(); // 创建JSch对象
// 按照用户名,主机ip,端口获取一个Session对象
try {
              logger.info("sftp [ ftpHost = "+ftpHost+" ftpPort = "+ftpPort+" ftpUserName = "+ftpUserName+" ftpPassword = "+ftpPassword+" ]");
               session = jsch.getSession(ftpUserName, ftpHost, ftpPort);
               logger.info("Session created.");
if (ftpPassword != null) {
                session.setPassword(ftpPassword); // 设置密码
               }
               String ftpTO=SysPropUtil.getValue("download.timeout");
if (!(ftpTO==null||"".equals(ftpTO))) {
int ftpTimeout=Integer.parseInt(ftpTO);
                   session.setTimeout(ftpTimeout); // 设置timeout时候
               }
//并且一旦计算机的密匙发生了变化，就拒绝连接。
               session.setConfig("StrictHostKeyChecking", "no");
//默认值是 “yes” 此处是由于我们SFTP服务器的DNS解析有问题，则把UseDNS设置为“no”
               session.setConfig("UseDNS", "no");
               session.connect(); // 经由过程Session建树链接
               logger.debug("Session connected.");
               logger.debug("Opening SFTP Channel.");
               channel = (ChannelSftp) session.openChannel("sftp"); // 打开SFTP通道
               channel.connect(); // 建树SFTP通道的连接
               logger.debug("Connected successfully to ftpHost = " + ftpHost + ",as ftpUserName = "
                 + ftpUserName + ", returning: " + channel);
          } catch (JSchException e) {
// TODO Auto-generated catch block
              e.printStackTrace();
              logger.error("sftp getConnect error : "+e);
          }
return channel;
     }

public static void closeChannel() throws Exception {
try {
if (channel != null) {
                   channel.disconnect();
               }
if (session != null) {
                   session.disconnect();
               }
          } catch (Exception e) {
               logger.error("close sftp error", e);
throw new Exception( "close ftp error.");
          }
     }


public static void uploadFile(String localFile, String newName, String remoteFoldPath) throws Exception{
          InputStream input = null;
try {
             input = new FileInputStream(new File(localFile));
// 改变当前路径到指定路径 
           channel.cd(remoteFoldPath);
           channel.put(input, newName);
          } catch (Exception e) {
           logger.error("Upload file error", e);
throw new Exception( "Upload file error.");
          } finally {
if (input != null) {
try {
             input.close();
            } catch (IOException e) {
throw new Exception("Close stream error.");
            }
           }
          }
     }


public void downloadFile(String remoteFile, String remotePath, String localFile) throws Exception {
          logger.info("sftp download File remotePath :"+remotePath+File.separator+remoteFile+" to localPath : "+localFile+" !");
          OutputStream output = null;
          File file = null;
try {
               file = new File(localFile);
if (!checkFileExist(localFile)) {
                file.createNewFile();
               }
               output = new FileOutputStream(file);
               channel.cd(remotePath);
               channel.get(remoteFile, output);
          } catch (Exception e) {
               logger.error("Download file error", e);
throw new Exception("Download file error.");
          } finally {
if (output != null) {
try {
                        output.close();
                    } catch (IOException e) {
throw new Exception("Close stream error.");
                    }
               }

          }
     }


@SuppressWarnings("unchecked")
public Vector listFiles(String remotePath) throws Exception {
          Vector vector = null;
try {
           vector = channel.ls(remotePath);
          } catch (SftpException e) {
           logger.error("List file error", e);
throw new Exception("list file error.");
          }
return vector;
     }


private boolean checkFileExist(String localPath) {
          File file = new File(localPath);
return file.exists();
     }

public static void main(String[] args) throws Exception {
//初始化配置文件
try {
            SysPropUtil.init("\\updconfig.properties");
        } catch (Exception e1) {
// TODO Auto-generated catch block
            e1.printStackTrace();
        }
         SFTPProcessor ftpUtil = new SFTPProcessor();
         ChannelSftp channeltest = ftpUtil.getConnect();
         System.out.println(channeltest.isConnected());
         ftpUtil.downloadFile("cussplus_3.5.0.1.zip.001", "/opt/applog/msiUpdate/Kiosk/3.7/COMMON/PEK", "E:\\projectTest\\downloadPath\\cussplus_3.5.0.1.zip.001");
         ftpUtil.closeChannel();
         System.out.println(channeltest.isConnected());
     }
 }