java远程调用ssh2执行Linux命令

java SSH2远程登录Linux服务执行命令

前一段时间工作中用到了java远程调用Linux服务器，执行相关命令，因为比较常用，故此，在博客中记录下来。其中用到了ganymed-ssh2这个jar包，可以在http://www.ganymed.ethz.ch/ssh2/找到相关jar，不过这个jar目前好像已经停止维护了，还有一点是，这个jar，我在阿里的maven仓库中未找到。
好了，下面我们来贴下代码

/** *  */package com.neusoft.mid.cloong.web.page.inspect.ssh;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStreamWriter;import java.io.PrintWriter;import ch.ethz.ssh2.ChannelCondition;import ch.ethz.ssh2.Connection;import ch.ethz.ssh2.Session;import com.neusoft.mid.iamp.logger.LogService;public class SSHConnect {    private static LogService log = LogService.getLogger(SSHConnect.class);    private static final int TIMEOUT = 2000;    private static final int RECONNECT_TIMES = 20;    private String userName;    private String host;    private String pass;    private int port;    private int sleepTime;    private int waitTime;    public Session openConnection() throws Exception {        Connection connection = connect(host, port, TIMEOUT);        if (!connection.authenticateWithPassword(userName, pass)) {            throw new Exception("用户名密码错误");        }        log.info("登陆成功!");        Session session = connection.openSession();        session.requestPTY("");        session.startShell();        return session;    }    private Connection connect(String address, int port, long timeOut) {        Connection conn = new Connection(address, port);        int connectTimes = 1;        long waitTime = System.currentTimeMillis() + timeOut;        do {            try {                conn.connect();                break;            } catch (IOException e) {                log.error(null, "ssh连接到主机时出错", e);                connectTimes++;            }        } while (System.currentTimeMillis() < waitTime                && RECONNECT_TIMES <= connectTimes);        return conn;    }    public InputStream executeCommand(String command, Session session)            throws Exception {        if (command.equals("")) {            log.info("执行空指令");            return null;        }        PrintWriter out = null;        try {            out = new PrintWriter(new OutputStreamWriter(session.getStdin(),                    "UTF-8"));            out.println(command);            out.flush();            return handleBufferStr(session);        } finally {            if (null != out) {                out.close();            }        }    }    /**     * 处理接收的缓存数据     */    protected InputStream handleBufferStr(Session session) throws Exception {        ByteArrayOutputStream sb = new ByteArrayOutputStream();        ByteArrayOutputStream ersb = new ByteArrayOutputStream();        InputStream in = null;        try {            if (sleepTime == 0) {                return null;            }            Thread.sleep(sleepTime);            in = receiveMsg(sb, ersb, session);            return in;        } finally {            if (null != in) {                in.close();            }        }    }    /**     * 接收shell返回信息     *      * @param stdNormal     * @param stdError     * @return     * @throws Exception     */    protected InputStream receiveMsg(ByteArrayOutputStream stdNormal,            ByteArrayOutputStream stdError, Session session) throws Exception {        InputStream stdout = null;        try {            stdout = session.getStdout();            // InputStream stderr = session.getStderr();            int conditions = session.waitForCondition(                    ChannelCondition.STDOUT_DATA | ChannelCondition.STDERR_DATA                            | ChannelCondition.EOF, waitTime);            if ((conditions & ChannelCondition.TIMEOUT) != 0) {                log.error(null, "获取session数据超时");                throw new IOException("获取打印数据超时");            }            if ((conditions & ChannelCondition.EOF) != 0) {                log.error(null, "无数据可读");            }            while (stdout.available() > 0) {                return stdout;                /*                 * byte[] buffer = new byte[8192]; int len =                 * stdout.read(buffer); if (len > 0) { // this check is somewhat                 * paranoid if (log.isDebugEnable()) { //                 * log.debug("Receive msg :" + buffer); }                 * stdNormal.write(buffer, 0, len); }                 */            }            /*             * while (stderr.available() > 0) { byte[] buffer = new byte[8192];             * int len = stderr.read(buffer); if (len > 0) {// this check is             * somewhat paranoid if (log.isDebugEnable()) { //             * log.debug("Receive error msg :" + buffer); }             * stdError.write(buffer, 0, len); } }             */        } finally {            if (null != stdout) {                stdout.close();            }        }        return null;    }}

代码框架比较老，用的是struts，我把get/set相关删掉了，main方法懒得写了，其中先调用openConnection方法，然后调用executeCommand方法就可以获得相关返回结果。
特别要注意的是Thread.sleep(sleepTime);这行代码。这行代码让线程睡一段时间是为了等待Linux返回结果，如果不睡，或者睡的时间比较短，会出现无法获取结果，或结果获取不全的情况。具体时间可以去Linux执行相关命令计算需要睡的时间。

总结

其中这个jar还可以实现端口转发，反向代理，等相关功能，等后续再继续添加吧。另外，相关实现ssh2相关功能的jar还有很多，比如jsch等，大家有空可以研究学习下，后续可以一起交流下经验。