利用ssh实现服务器文件上传下载

通过ssh实现服务器文件上传下载

写在前面的话

之前记录过一篇使用apache的FTP开源组件实现服务器文件上传下载的方法，但是后来发现在删除的时候会有些权限问题，导致无法删除服务器上的文件。虽然在Windows上使用FileZilla Server设置读写权限后没问题，但是在服务器端还是有些不好用。

因为自己需要实现资源管理功能，除了单文件的FastDFS存储之外，一些特定资源的存储还是打算暂时存放服务器上，项目组同事说后面不会专门在服务器上开FTP服务，于是改成了sftp方式进行操作。

这个东西要怎么用

首先要去下载jsch jar包，地址是:http://www.jcraft.com/jsch/。网站上也写的很清楚：JSch is a pure Java implementation of SSH2. 这个是SSH2的纯Java实现。使用ip和端口，输入用户名密码就可以正常使用了，和Secure CRT使用方式一致。那么怎么来使用这个有用的工具呢？

其实不会写也没关系，官方也给出了示例，链接：http://www.jcraft.com/jsch/examples/Shell.java，来看一眼吧：

import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;

public class Shell{
 public static void main(String[] arg){

 try{
  JSch jsch=new JSch();

  //jsch.setKnownHosts("/home/foo/.ssh/known_hosts");

  String host=null;
  if(arg.length>0){
  host=arg[0];
  }
  else{
  host=JOptionPane.showInputDialog("Enter username@hostname",
    System.getProperty("user.name")+
    "@localhost"); 
  }
  String user=host.substring(0, host.indexOf('@'));
  host=host.substring(host.indexOf('@')+1);

  Session session=jsch.getSession(user, host, 22);

  String passwd = JOptionPane.showInputDialog("Enter password");
  session.setPassword(passwd);

  UserInfo ui = new MyUserInfo(){
  public void showMessage(String message){
   JOptionPane.showMessageDialog(null, message);
  }
  public boolean promptYesNo(String message){
   Object[] options={ "yes", "no" };
   int foo=JOptionPane.showOptionDialog(null, 
     message,
     "Warning", 
     JOptionPane.DEFAULT_OPTION, 
     JOptionPane.WARNING_MESSAGE,
     null, options, options[0]);
   return foo==0;
  }

  // If password is not given before the invocation of Session#connect(),
  // implement also following methods,
  // * UserInfo#getPassword(),
  // * UserInfo#promptPassword(String message) and
  // * UIKeyboardInteractive#promptKeyboardInteractive()

  };

  session.setUserInfo(ui);

  // It must not be recommended, but if you want to skip host-key check,
  // invoke following,
  // session.setConfig("StrictHostKeyChecking", "no");

  //session.connect();
  session.connect(30000); // making a connection with timeout.

  Channel channel=session.openChannel("shell");

  // Enable agent-forwarding.
  //((ChannelShell)channel).setAgentForwarding(true);

  channel.setInputStream(System.in);
  

  channel.setOutputStream(System.out);

  

  

  //channel.connect();
  channel.connect(3*1000);
 }
 catch(Exception e){
  System.out.println(e);
 }
 }

 public static abstract class MyUserInfo
implements UserInfo, UIKeyboardInteractive{
 public String getPassword(){ return null; }
 public boolean promptYesNo(String str){ return false; }
 public String getPassphrase(){ return null; }
 public boolean promptPassphrase(String message){ return false; }
 public boolean promptPassword(String message){ return false; }
 public void showMessage(String message){ }
 public String[] promptKeyboardInteractive(String destination,
     String name,
     String instruction,
     String[] prompt,
     boolean[] echo){
  return null;
 }
 }
}

在这个代码中，我们基本上能看到需要的东西，首先我们要创建用户信息，这个主要是给认证的时候用的，只要实现 UserInfo, UIKeyboardInteractive这两个接口就好了，然后通过创建session会话，将userInfo设置进去，最后进行连接即可。

封装文件上传下载

上面是Jsch的基本使用方法，也就是些基本套路。下面我们来自己封装一下自己要使用的功能，实现文件的上传下载等一系列操作。

首先，也来创建个UserInfo：

public class MyUserInfo implements UserInfo, UIKeyboardInteractive{
 public String getPassword(){ return null; }
 public boolean promptYesNo(String str){
  return true;
 }
 public String getPassphrase(){ return null; }
 public boolean promptPassphrase(String message){ return true; }
 public boolean promptPassword(String message){
  return true;
 }
 public void showMessage(String message){
 }
 @Override
 public String[] promptKeyboardInteractive(String arg0, String arg1,
   String arg2, String[] arg3, boolean[] arg4) {
  return null;
 }
}

下面是实现类：

package com.tfxiaozi.common.utils;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;

import org.apache.log4j.Logger;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
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;
import com.jcraft.jsch.SftpProgressMonitor;

public class Ssh {
 Logger logger = Logger.getLogger(this.getClass());
 private String host = "";
 private String user = "";
 private int port = 22; 
 private String password = "";
 private static final String PROTOCOL = "sftp";
 JSch jsch = new JSch();
 private Session session;
 private Channel channel;
 private ChannelSftp sftp;

 public String getHost() {
  return host;
 }

 public void setHost(String host) {
  this.host = host;
 }

 public String getUser() {
  return user;
 }

 public void setUser(String user) {
  this.user = user;
 }

 public Ssh() {
 }

 public Ssh(String host, int port, String user, String password) {
  this.host = host;
  this.user = user;
  this.password = password;
  this.port = port;
 }

 
 public void connect() throws JSchException {
  if (session == null) {
   session = jsch.getSession(user, host, port);
   MyUserInfo ui = new MyUserInfo();
   session.setUserInfo(ui);
   session.setPassword(password);
   session.connect();
   channel = session.openChannel(PROTOCOL);
   channel.connect();
   sftp = (ChannelSftp)channel;
  }
 }

 
 public void disconnect() {
  if (session != null) {
   session.disconnect();
   session = null;
  }
 }

 
 public boolean upload(String localFileName, String remoteFileName) throws Exception{
  boolean bSucc = false;
  try {
   SftpProgressMonitor monitor=new MyProgressMonitor();
   int mode=ChannelSftp.OVERWRITE;
   sftp.put(localFileName, remoteFileName, monitor, mode); 
   bSucc = true;
  } catch(Exception e) {
   logger.error(e);
  } finally {
   if (null != channel) {
    channel.disconnect();
   }
  }
  return bSucc;
 }

 
 public boolean deteleFile(String directory, String fileName) {
  boolean flag = false;
  try {
   sftp.cd(directory);
   sftp.rm(fileName);
   flag = true;
  } catch (SftpException e) {
   flag = false;
   logger.error(e);
  }
  return flag;
 }

 
 public String deleteDir(String directory, boolean sure) {
  String command = "rm -rf " + directory;
  String result = execCommand(command, true);
  return result;
 }

 
 public void compressDir(String directory, String compressName) throws SftpException {
  String command = "cd "+ directory +"nzip -r " + compressName + " ./" + compressName.substring(0, compressName.lastIndexOf("."));
  execCommand(command, true);
 }


 
 public boolean download(String localFileName, String remoteFileName) {
  boolean bSucc = false;
  Channel channel = null;
  try {
   SftpProgressMonitor monitor = new MyProgressMonitor();
   sftp.get(remoteFileName, localFileName, monitor, ChannelSftp.OVERWRITE); 
   bSucc = true;
  } catch(Exception e) {
   logger.error(e);
  } finally {
   if (null != channel) {
    channel.disconnect();
   }
  }
  return bSucc;
 }

 
 public String execCommand(String command, boolean flag) {
  Channel channel = null;
  InputStream in = null;
  StringBuffer sb = new StringBuffer("");
  try {
   channel = session.openChannel("exec");
   System.out.println("command:" + command);
   ((ChannelExec)channel).setCommand("export TERM=ansi && " + command);
   ((ChannelExec)channel).setErrStream(System.err);
   in = channel.getInputStream();
   channel.connect();
   if (flag) {
    byte[] tmp = new byte[10240];
    while (true) {
     while (in.available()>0) {
      int i = in.read(tmp, 0, 10240);
      if(i < 0) {
break;
      }
      sb.append(new String(tmp, 0, i));
     }
     if (channel.isClosed()){
      break;
     }
    }
   }
   in.close();
  } catch(Exception e){
   logger.error(e);
  } finally {
   if (channel != null) {
    channel.disconnect();
   }
  }
  return sb.toString();
 }

 
 public String[] getCpuInfo() {
  Channel channel = null;
  InputStream in = null;
  StringBuffer sb = new StringBuffer("");
  try {
   channel = session.openChannel("exec");
   ((ChannelExec)channel).setCommand("export TERM=ansi && top -bn 1");//ansi一定要加
   in = channel.getInputStream();
   ((ChannelExec)channel).setErrStream(System.err);
   channel.connect();
   byte[] tmp = new byte[10240];
   while (true) {
    while (in.available()>0) {
     int i = in.read(tmp, 0, 10240);
     if(i < 0) {
      break;
     }
     sb.append(new String(tmp, 0, i));
    }
    if (channel.isClosed()){
     break;
    }
   }
  } catch(Exception e){
   logger.error(e);
  } finally {
   if (channel != null) {
    channel.disconnect();
   }
  }
  String buf = sb.toString();
  if (buf.indexOf("Swap") != -1) {
   buf = buf.substring(0, buf.indexOf("Swap"));
  }
  if (buf.indexOf("Cpu") != -1) {
   buf = buf.substring(buf.indexOf("Cpu"), buf.length());
  }
  buf.replaceAll(" ", " ");
  return buf.split("\n");
 }

 
 public String getHardDiskInfo() throws Exception{
  Channel channel = null;
  InputStream in = null;
  StringBuffer sb = new StringBuffer("");
  try {
   channel = session.openChannel("exec");
   ((ChannelExec)channel).setCommand("df -lh");
   in = channel.getInputStream();
   ((ChannelExec)channel).setErrStream(System.err);
   channel.connect();

   byte[] tmp = new byte[10240];
   while (true) {
    while (in.available()>0) {
     int i = in.read(tmp, 0, 10240);
     if(i < 0) {
      break;
     }
     sb.append(new String(tmp, 0, i));
    }
    if (channel.isClosed()){
     break;
    }
   }
  } catch(Exception e){
   throw new RuntimeException(e);
  } finally {
   if (channel != null) {
    channel.disconnect();
   }
  }
  String buf = sb.toString();
  String[] info = buf.split("n");
  if(info.length > 2) {//first line: Filesystem Size Used Avail Use% Mounted on
   String tmp = "";
   for(int i=1; i< info.length; i++) {
    tmp = info[i];
    String[] tmpArr = tmp.split("%");
    if(tmpArr[1].trim().equals("/")){
     boolean flag = true;
     while(flag) {
      tmp = tmp.replaceAll(" ", " ");
      if (tmp.indexOf(" ") == -1){
flag = false;
      }
     }

     String[] result = tmp.split(" ");
     if(result != null && result.length == 6) {
      buf = result[1] + " total, " + result[2] + " used, " + result[3] + " free";
      break;
     } else {
      buf = "";
     }
    }
   }
  } else {
   buf = "";
  }
  return buf;
 }

 
 public double getFreeDisk() throws Exception {
  String hardDiskInfo = getHardDiskInfo();
  if(hardDiskInfo == null || hardDiskInfo.equals("")) {
   logger.error("get free harddisk space failed.....");
   return -1;
  }
  String[] diskInfo = hardDiskInfo.replace(" ", "").split(",");
  if(diskInfo == null || diskInfo.length == 0) {
   logger.error("get free disk info failed.........");
   return -1;
  }
  String free = diskInfo[2];
  free = free.substring(0, free.indexOf("free"));
  //System.out.println("free space:" + free);
  String unit = free.substring(free.length()-1);
  //System.out.println("unit:" + unit);
  String freeSpace = free.substring(0, free.length()-1);
  double freeSpaceL = Double.parseDouble(freeSpace);
  //System.out.println("free spaceL:" + freeSpaceL);
  if(unit.equals("K")) {
   return freeSpaceL*1024;
  }else if(unit.equals("M")) {
   return freeSpaceL*1024*1024;
  } else if(unit.equals("G")) {
   return freeSpaceL*1024*1024*1024;
  } else if(unit.equals("T")) {
   return freeSpaceL*1024*1024*1024*1024;
  } else if(unit.equals("P")) {
   return freeSpaceL*1024*1024*1024*1024*1024;
  }
  return 0;
 }

 
 @SuppressWarnings("rawtypes")
 public List listFiles(String directory) throws Exception {
  Vector fileList = null;
  List fileNameList = new ArrayList();
  fileList = sftp.ls(directory);
  Iterator it = fileList.iterator();
  while (it.hasNext()) {
   String fileName = ((ChannelSftp.LsEntry) it.next()).getFilename();
   if (fileName.startsWith(".") || fileName.startsWith("..")) {
    continue;
   }
   fileNameList.add(fileName);
  }
  return fileNameList;
 }

 public boolean mkdir(String path) {
  boolean flag = false;
  try {
   sftp.mkdir(path);
   flag = true;
  } catch (SftpException e) {
   flag = false;
  }
  return flag;
 }
}

测试一下

public static void main(String[] arg) throws Exception{
  Ssh ssh = new Ssh("10.10.10.83", 22, "test", "test");
  try {
   ssh.connect();
  } catch (JSchException e) {
   e.printStackTrace();
  }

  


  


  //String []buf = ssh.getCpuInfo();
  //System.out.println("cpu:" + buf[0]);
  //System.out.println("memo:" + buf[1]);
  //System.out.println(ssh.getHardDiskInfo().replace(" ", ""));
  //System.out.println(ssh.getFreeDisk());


  

  


  
  //ssh.sftp.setFilenameEncoding("UTF-8");

  


  


  

  

  

  

  //下面这个会解压到webapp1目录,webapp1/test/xxx
  //ssh.execCommand("unzip /home/tfxiaozi/webapp1/test.zip -d /home/tfxiaozi/webapp1", true);
  //下面这个会解压到/webapp1/test目录，也是webapp1/test/test/xxx
  //ssh.execCommand("unzip /home/tfxiaozi/webapp1/test.zip -d /home/tfxiaozi/webapp1", true);

  //ssh.compressDir("/home/tfxiaozi/webapp1", "test.zip");

  //ssh.sftp.cd("/home/tfxiaozi/webapp1");
  //ssh.compressDir("/home/tfxiaozi/webapp1", "test.zip");

  
  //ssh.getHardDiskInfo();
  System.out.println(ssh.getFreeDisk());
  ssh.disconnect();
 }

以上就是直接使用linux方式进行操作，不过需要注意的是，对于中文文件，在解压的时候，传入的时候会有可能乱码，需要加上参数，如unzip -O cp936 test.zip -d /home/tfxiaozi/test。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。