如何使用jsch与ProxyCommands进行端口转发

ProxyCommand ssh proxyhost.com -t nc %h %p
IdentityFile /home/username/username_dsa_key

然后我运行以下命令来执行portforwarding以将hostmachine.com:54321映射到我的localhost：12345：

ssh -A -L12345:localhost:54321 hostmachine.com

现在我想用Jsch库做这些,但是在打开会话中的通道后我无法弄清楚如何连接到第二个主机：

        String proxyHost = "proxyhost.com";
        String host = "hostmachine.com";
        int lport = 12345;
        String rhost = "localhost";
        int rport = 54321;

        JSch jsch=new JSch();
        jsch.setKnownHosts("/home/{user}/.ssh/known_hosts");
        jsch.addIdentity("/home/{user}/.ssh/{user}_dsa_key",passphrase);

        Session session1 = jsch.getSession(user,proxyHost,22);
        session1.connect(3000);
        System.out.println(session1.isConnected());
        Channel channel = session1.openChannel("shell");

        ////// Now what? :)


        channel.disconnect();
        session1.disconnect();

任何想法？

p.s：我已经在www.jcraft.com/jsch/examples/上阅读了样本,但不幸的是,他们在这种情况下没有帮助.

谢谢！

http://www.jcraft.com/jsch/examples/JumpHosts.java.html

,但如果使用本机“ssh”命令很重要,您将找到该类
在jsch-0.1.50的Session.java的注释中的ProxyCommand,

/*
// setProxyCommand("ssh -l user2 host2 -o 'ProxyCommand ssh user1@host1 nc host2 22' nc %h %p")
public void setProxyCommand(String command){
  setProxy(new ProxyCommand(command));
}

class ProxyCommand implements Proxy {
  String command;
  Process p = null;
  InputStream in = null;
  OutputStream out = null;
  ProxyCommand(String command){
    this.command = command;
  }
  public void connect(SocketFactory socket_factory, String host, int port, int timeout) throws Exception {
    String _command = command.replace("%h", host);
    _command = _command.replace("%p", new Integer(port).toString());
    p = Runtime.getRuntime().exec(_command);
    in = p.getInputStream();
    out = p.getOutputStream();
  }
  public Socket getSocket() { return null; }
  public InputStream getInputStream() { return in; }
  public OutputStream getOutputStream() { return out; }
  public void close() {
    try{
      if(p!=null){
        p.getErrorStream().close();
        p.getOutputStream().close();
        p.getInputStream().close();
        p.destroy();
        p=null;
      }
    }
    catch(IOException e){
    }
  }
}
*/