Java操作Linuxshell并且获取返回值

/**
*
*/
package com.king.weixin.util;
import java.io.BufferedReader;
import java.io.InputStream;
/**
* @author kingstudy@vip.qq.com
* @version 创建时间：2018年6月30日 上午11:28:01
* @ClassName LinuxUtil
* @Description 操作Linux系统的相关工具类
*/
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.nio.charset.Charset;
import java.util.Properties;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;

public class LinuxUtil {
private static final Logger log = LoggerFactory.getLogger(LinuxUtil.class);

private static ChannelExec channelExec;

private static Session session = null;

private static int timeout = 60000;
// 测试代码
public static void main(String[] args){
try{
versouSshUtil("192.168.1.1","root","King",22);
//System.out.println(1);
runCmd("cat /dev/urandom |od -x | tr -d ' '| head -n 1","UTF-8");
// System.out.println(2);
}catch (Exception e){
// TODO Auto-generated catch block
e.printStackTrace();
}
}

//java 操控Linux
/**
* 连接远程服务器
* @param host ip地址
* @param userName 登录名
* @param password 密码
* @param port 端口
* @throws Exception
*/
public static void versouSshUtil(String host,String userName,String password,int port) throws Exception{
log.info("尝试连接到....host:" + host + ",username:" + userName + ",password:" + password + ",port:"
+ port);
JSch jsch = new JSch(); // 创建JSch对象
session = jsch.getSession(userName, host, port); // 根据用户名，主机ip，端口获取一个Session对象
session.setPassword(password); // 设置密码
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config); // 为Session对象设置properties
session.setTimeout(timeout); // 设置timeout时间
session.connect(); // 通过Session建立链接
}

/**
* 在远程服务器上执行命令
* @param cmd 要执行的命令字符串
* @param charset 编码
* @throws Exception
*/
public static String runCmd(String cmd,String charset) throws Exception{
channelExec = (ChannelExec) session.openChannel("exec");
channelExec.setCommand(cmd);
channelExec.setInputStream(null);
channelExec.setErrStream(System.err);
channelExec.connect();
InputStream in = channelExec.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in, Charset.forName(charset)));
StringBuffer sb=new StringBuffer();
String buf = null;
while ((buf = reader.readLine()) != null){
//System.out.println("111");
sb.append(buf);
}
//System.out.println(sb.toString());
reader.close();
channelExec.disconnect();
return sb.toString();
}
}