import ch.ethz.ssh2.Connection;
import ch.ethz.ssh2.Session;
import ch.ethz.ssh2.StreamGobbler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;


public class BashUtil {

    private Logger logger = LoggerFactory.getLogger(BashUtil.class);

    private String hostname;

    private String username;

    private String password;

    private int port;

    private Connection conn;

    private BashUtil() {
    }

    public BashUtil(String hostname, String username, String password) {
        this(hostname, username, password, 22);
    }

    public BashUtil(String hostname, String username, String password, Integer port) {
        this.hostname = hostname;
        this.username = username;
        this.password = password;
        if (port == null) {
            port = 22;
        } else {
            this.port = port;
        }
    }

    /**
     * 创建连接并认证
     * @return
     */
    public Boolean connection() {
        try {
            conn = new Connection(hostname, port);
            conn.connect();
            boolean isAuthenticated = conn.authenticateWithPassword(username, password);
            return isAuthenticated;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * 关闭连接
     */
    public void close() {
        try {
            conn.close();
            conn = null;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 执行shell命令
     * @param command
     * @return
     */
    public List<String> command(String command) {
        if (conn == null && !connection()) {
            logger.error("Authentication failed.");
            return null;
        }
        List<String> result = new ArrayList<String>();
        try {
            Session sess = conn.openSession();
            sess.execCommand(command);
            InputStream stdout = new StreamGobbler(sess.getStdout());
            InputStream stderr = new StreamGobbler(sess.getStderr());
            BufferedReader br_out = new BufferedReader(new InputStreamReader(stdout, "utf-8"));
            BufferedReader br_err = new BufferedReader(new InputStreamReader(stderr, "utf-8"));
            StringBuffer sb_err = new StringBuffer();
            String line = null;
            while ((line = br_out.readLine()) != null) {
                result.add(line.trim());
            }
            while ((line = br_err.readLine()) != null) {
                sb_err.append(line + "\n");
            }
            if (isNotEmpty(sb_err.toString())) {
                logger.error(sb_err.toString());
                return null;
            }
            return result;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }


    private static boolean isEmpty(String content) {
        if (content == null) {
            return true;
        } else {
            return "".equals(content.trim()) || "null".equalsIgnoreCase(content.trim());
        }
    }

    private static boolean isNotEmpty(String content) {
        return !isEmpty(content);
    }

    public static void main(String[] args){
        String hostname = "192.168.123.234";   // 此处根据实际情况，换成自己需要访问的主机IP
        String userName = "root";
        String password = "password";
        Integer port = 22;
        String command = "cd /home/miracle&&pwd&&ls&&cat luna.txt";

        BashUtil bashUtil = new BashUtil(hostname, userName, password, port);
        List<String> resultList = bashUtil.command(command);
        StringBuffer result = new StringBuffer("");
        resultList.forEach(str -> result.append(str + "\n"));

        System.out.println("执行的结果如下: \n" + result.toString());
    }
}

执行的结果如下: 
/home/miracle
luna.txt
Hello, I‘m SshUtil.
Nice to meet you.^_^

        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.21</version>
        </dependency>


        <!-- ssh  -->
        <dependency>
            <groupId>ch.ethz.ganymed</groupId>
            <artifactId>ganymed-ssh2</artifactId>
            <version>262</version>
        </dependency>