java jsch执行远程命令

/* 
  * SSHManager
  * 
  * @author cabbott
  * @version 1.0
  */
package jsch;

import com.jcraft.jsch.*;

import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Level;
import java.util.logging.Logger;

public class SSHManager
{
    private static final Logger LOGGER = Logger.getLogger(SSHManager.class.getName());

    private JSch jschSSHChannel;

    private String strUserName;

    private String strConnectionIP;

    private int intConnectionPort;

    private String strPassword;

    private Session sesConnection;

    private int intTimeOut;

    private void doCommonConstructorActions(String userName, String password, String connectionIP,
            String knownHostsFileName)
    {
        jschSSHChannel = new JSch();

        try
        {
            jschSSHChannel.setKnownHosts(knownHostsFileName);
        }
        catch (JSchException jschX)
        {
            logError(jschX.getMessage());
        }

        strUserName = userName;
        strPassword = password;
        strConnectionIP = connectionIP;
    }

    public SSHManager(String userName, String password, String connectionIP, String knownHostsFileName)
    {
        doCommonConstructorActions(userName, password, connectionIP, knownHostsFileName);
        intConnectionPort = 22;
        intTimeOut = 60000;
    }

    public SSHManager(String userName, String password, String connectionIP, String knownHostsFileName,
            int connectionPort)
    {
        doCommonConstructorActions(userName, password, connectionIP, knownHostsFileName);
        intConnectionPort = connectionPort;
        intTimeOut = 60000;
    }

    public SSHManager(String userName, String password, String connectionIP, String knownHostsFileName,
            int connectionPort, int timeOutMilliseconds)
    {
        doCommonConstructorActions(userName, password, connectionIP, knownHostsFileName);
        intConnectionPort = connectionPort;
        intTimeOut = timeOutMilliseconds;
    }

    public String connect()
    {
        String errorMessage = null;

        try
        {
            sesConnection = jschSSHChannel.getSession(strUserName, strConnectionIP, intConnectionPort);
            sesConnection.setConfig("StrictHostKeyChecking", "no");
            sesConnection.setPassword(strPassword);
            // UNCOMMENT THIS FOR TESTING PURPOSES, BUT DO NOT USE IN PRODUCTION
            // sesConnection.setConfig("StrictHostKeyChecking", "no");
            sesConnection.connect(intTimeOut);
        }
        catch (JSchException jschX)
        {
            errorMessage = jschX.getMessage();
        }

        return errorMessage;
    }

    private String logError(String errorMessage)
    {
        if (errorMessage != null)
        {
            LOGGER.log(Level.SEVERE, "{0}:{1} - {2}", new Object[] {strConnectionIP, intConnectionPort, errorMessage});
        }

        return errorMessage;
    }

    private String logWarning(String warnMessage)
    {
        if (warnMessage != null)
        {
            LOGGER.log(Level.WARNING, "{0}:{1} - {2}", new Object[] {strConnectionIP, intConnectionPort, warnMessage});
        }

        return warnMessage;
    }

    public String sendCommand(String command)
    {
        StringBuilder outputBuffer = new StringBuilder();

        try
        {
            Channel channel = sesConnection.openChannel("exec");
            ((ChannelExec) channel).setCommand(command);
            InputStream commandOutput = channel.getInputStream();
            channel.connect();
            int readByte = commandOutput.read();

            while (readByte != 0xffffffff)
            {
                outputBuffer.append((char) readByte);
                readByte = commandOutput.read();
            }

            channel.disconnect();
        }
        catch (IOException ioX)
        {
            logWarning(ioX.getMessage());
            return null;
        }
        catch (JSchException jschX)
        {
            logWarning(jschX.getMessage());
            return null;
        }

        return outputBuffer.toString();
    }

    public void close()
    {
        sesConnection.disconnect();
    }

}