1. 使用ChannelShell

(ChannelShell) session.openChannel("shell");

2. 如果因为返回信息太多，返回的是more，没有返回全部，则发送一个空格过去即可；

              if (s.indexOf("--More--") >= 0 ) {
                    os.write((" ").getBytes());
                    os.flush();
                }

全部代码如下：

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.ChannelShell;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;

public class JSchDemo {
    Logger logger = null;
    private String charset = "UTF-8"; //
    private String user; //
    private String passwd; //
    private String host; //
    private JSch jsch;
    private Session session;
        String path = null;
        String retn = null;

    public JSchDemo(String user, String passwd, String host) {
        this.user = user;
        this.passwd = passwd;
        this.host = host;
        this.path = getClass().getResource("/").getFile().toString();
        PropertyConfigurator.configure(path + File.separator + "log4j.properties");

        System.out.println("Init JSchDemo....");
        this.logger = Logger.getLogger(JSchDemo.class);
    }

    public static void main(String[] args) throws Exception {
        
        
        String host= args[0];
        int port= Integer.valueOf(args[1]) ;
        String user= args[2];
        String password= args[3];
        
        String command1="ls -ltr";
        JSchDemo demo = new JSchDemo(user, password, host);
        System.out.println(demo.path);
        try{
            
            java.util.Properties config = new java.util.Properties(); 
            config.put("StrictHostKeyChecking", "no");
            JSch jsch = new JSch();
            Session session=jsch.getSession(user, host, port);
            session.setPassword(password);
            session.setConfig(config);
            session.connect();

            System.out.println("Connected");
            demo.logger.debug("Connected");
            
            ChannelShell channel=(ChannelShell) session.openChannel("shell");
            InputStream in = channel.getInputStream();
            channel.setPty(true);
            channel.connect();
            OutputStream os = channel.getOutputStream();
            os.write((command1 + "\r\n").getBytes());
            os.flush();

            byte[] tmp=new byte[1024];
            while(true){
              while(in.available()>0){
                int i=in.read(tmp, 0, 1024);
                if(i<0)break;
                String s = new String(tmp, 0, i);
                if (s.indexOf("--More--") >= 0 ) {
                    os.write((" ").getBytes());
                    os.flush();
                }
                System.out.print(s);
                demo.logger.debug(s);
              }
              if(channel.isClosed()){
                System.out.println("exit-status: "+channel.getExitStatus());
                demo.logger.debug("exit-status: "+channel.getExitStatus());
                break;
              }
              try{Thread.sleep(1000);}catch(Exception ee){}
            }
            os.close();
            in.close();
            channel.disconnect();
            session.disconnect();
            System.out.println("DONE");
            demo.logger.debug("DONE");
        }catch(Exception e){
            e.printStackTrace();
        }

    }
    
}

附上ssh rfc地址：
ssh rfc