java实现ssh连接服务器的方法步骤

<dependency>
<groupId>com.jcraft</groupId>
<artifactId>jsch</artifactId>
<version>0.1.54</version>
</dependency>

import com.jcraft.jsch.*;
import java.io.*;
import java.util.concurrent.TimeUnit;
import static java.lang.String.format;
public class SSHExecutor {
    private static long INTERVAL = 100L;
    private static int SESSION_TIMEOUT = 30000;
    private static int CHANNEL_TIMEOUT = 3000;
    private JSch jsch = null;
    private Session session = null;
    public SSHExecutor(SSHInfo sshInfo) throws JSchException {
        jsch = new JSch();
        session = jsch.getSession(sshInfo.getUser(), sshInfo.getHost(), sshInfo.getPort());
        session.setPassword(sshInfo.getPassword());
        session.setUserInfo(new MyUserInfo());
        session.connect(SESSION_TIMEOUT);
    }
    /*
    * 注意编码转换
    * */
    public long shell(String cmd, String outputFileName) throws JSchException, IOException, InterruptedException {
        long start = System.currentTimeMillis();
        Channel channel = session.openChannel("shell");
        PipedInputStream pipeIn = new PipedInputStream();
        PipedOutputStream pipeOut = new PipedOutputStream(pipeIn);
        FileOutputStream fileOut = new FileOutputStream(outputFileName, true);
        channel.setInputStream(pipeIn);
        channel.setOutputStream(fileOut);
        channel.connect(CHANNEL_TIMEOUT);
        pipeOut.write(cmd.getBytes());
        Thread.sleep(INTERVAL);
        pipeOut.close();
        pipeIn.close();
        fileOut.close();
        channel.disconnect();
        return System.currentTimeMillis() - start;
    }
    public int exec(String cmd) throws IOException, JSchException, InterruptedException {
        ChannelExec channelExec = (ChannelExec) session.openChannel("exec");
        channelExec.setCommand(cmd);
        channelExec.setInputStream(null);
        channelExec.setErrStream(System.err);
        InputStream in = channelExec.getInputStream();
        channelExec.connect();
        int res = -1;
        StringBuffer buf = new StringBuffer(1024);
        byte[] tmp = new byte[1024];
        while (true) {
            while (in.available() > 0) {
                int i = in.read(tmp, 0, 1024);
                if (i < 0) break;
                buf.append(new String(tmp, 0, i));
            }
            if (channelExec.isClosed()) {
                res = channelExec.getExitStatus();
                System.out.println( format("Exit-status: %d", res));
                break;
            }
            TimeUnit.MILLISECONDS.sleep(100);
        }
        System.out.println(buf.toString());
        channelExec.disconnect();
        return res;
    }
    public Session getSession() {
        return session;
    }
    public void close() {
        getSession().disconnect();
    }
    /*
    * SSH连接信息
    * */
    public static class SSHInfo {
        private String user;
        private String password;
        private String host;
        private int port;
        public SSHInfo(String user, String password, String host, int port) {
            this.user = user;
            this.password = password;
            this.host = host;
            this.port = port;
        }
        public String getUser() {
            return user;
        }
        public String getPassword() {
            return password;
        }
        public String getHost() {
            return host;
        }
        public int getPort() {
            return port;
        }
    }
    /*
    * 自定义UserInfo
    * */
    private static class MyUserInfo implements UserInfo {
        @Override
        public String getPassphrase() {
            return null;
        }
        @Override
        public String getPassword() {
            return null;
        }
        @Override
        public boolean promptPassword(String s) {
            return false;
        }
        @Override
        public boolean promptPassphrase(String s) {
            return false;
        }
        @Override
        public boolean promptYesNo(String s) {
            System.out.println(s);
            System.out.println("true");
            return true;
        }
        @Override
        public void showMessage(String s) {
        }
    }
}

import com.jcraft.jsch.JSchException;
import java.io.IOException;
public class SSHUtil {
    public static SSHExecutor sshExecutor;
    public static void start (){
        // 此处配置服务器信息
        SSHExecutor.SSHInfo sshInfo = new SSHExecutor.SSHInfo("用户名", "密码", "host", "port");
        try {
            sshExecutor = new SSHExecutor(sshInfo);
            System.err.println("ssh灾备日志服务器已链接");
        } catch (Exception e) {
            System.err.println("ssh灾备日志服务器链接失败！！");
            e.printStackTrace();
            sshExecutor.close();
        }
    }
    /**
    * 运行cmd命令
    */
    public static void runCmd (String cmd) throws JSchException, IOException, InterruptedException {
        sshExecutor.exec(cmd);
    }
}

SSHUtil.start();

SSHUtil.runCmd("cmd");