Java SSH远程执行Shell脚本实现

此程序需要ganymed-ssh2-build210.jar包。
下载地址：http://www.ganymed.ethz.ch/ssh2/
为了调试方便，可以将\ganymed-ssh2-build210\src下的代码直接拷贝到我们的工程里，
此源码的好处就是没有依赖很多其他的包，拷贝过来干干净净。

此程序的目的是执行远程机器上的Shell脚本。
远程机器IP：***.**.**.***
用户名：sshapp
密码：sshapp
登录后用pwd命令，显示当前目录为：/sshapp.
在/sshapp/myshell/目录下有myTest.sh文件，内容如下：
 

echo $ 1  $ 2  $ #
#print $1

我们的Java代码RmtShellExecutor.java：
 

/** *//**
 * 远程执行shell脚本类
 * @author l
 */
public class RmtShellExecutor {

    /** *//**  */
    private Connection conn;
    /** *//** 远程机器IP */
    private String     ip;
    /** *//** 用户名 */
    private String     usr;
    /** *//** 密码 */
    private String     psword;
    private String     charset = Charset.defaultCharset().toString();

    private static final int TIME_OUT = 1000 * 5 * 60;

    /** *//**
     * 构造函数
     * @param param 传入参数Bean 一些属性的getter setter 实现略
     */
    public RmtShellExecutor(ShellParam param) {
        this.ip = param.getIp();
        this.usr = param.getUsername();
        this.psword = param.getPassword();
    }

    /** *//**
     * 构造函数
     * @param ip
     * @param usr
     * @param ps
     */
    public RmtShellExecutor(String ip, String usr, String ps) {
        this.ip = ip;
        this.usr = usr;
        this.psword = ps;
    }

    /** *//**
     * 登录
     *
     * @return
     * @throws IOException
     */
    private boolean login() throws IOException {
        conn = new Connection(ip);
        conn.connect();
        return conn.authenticateWithPassword(usr, psword);
    }

    /** *//**
     * 执行脚本
     *
     * @param cmds
     * @return
     * @throws Exception
     */
    public int exec(String cmds) throws Exception {
        InputStream stdOut = null;
        InputStream stdErr = null;
        String outStr = "";
        String outErr = "";
        int ret = -1;
        try {
            if (login()) {
                // Open a new {@link Session} on this connection
                Session session = conn.openSession();
                // Execute a command on the remote machine.
                session.execCommand(cmds);

                stdOut = new StreamGobbler(session.getStdout());
                outStr = processStream(stdOut, charset);

                stdErr = new StreamGobbler(session.getStderr());
                outErr = processStream(stdErr, charset);

                session.waitForCondition(ChannelCondition.EXIT_STATUS, TIME_OUT);

                System.out.println("outStr=" + outStr);
                System.out.println("outErr=" + outErr);

                ret = session.getExitStatus();
            } else {
                throw new AppException("登录远程机器失败" + ip); // 自定义异常类 实现略
            }
        } finally {
            if (conn != null) {
                conn.close();
            }
            IOUtils.closeQuietly(stdOut);
            IOUtils.closeQuietly(stdErr);
        }
        return ret;
    }

    /** *//**
     * @param in
     * @param charset
     * @return
     * @throws IOException
     * @throws UnsupportedEncodingException
     */
    private String processStream(InputStream in, String charset) throws Exception {
        byte[] buf = new byte[1024];
        StringBuilder sb = new StringBuilder();
        while (in.read(buf) != -1) {
            sb.append(new String(buf, charset));
        }
        return sb.toString();
    }

    public static void main(String args[]) throws Exception {
        RmtShellExecutor exe = new RmtShellExecutor("***.**.**.***", "sshapp", "sshapp");
        // 执行myTest.sh 参数为java Know dummy
        System.out.println(exe.exec("sh /webapp/myshell/myTest.sh java Know dummy"));
//        exe.exec("uname -a && date && uptime && who");
    }
}

执行后结果：
 

outStr = java Know  3
outErr =
0   //  getExitStatus方法的返回值

 注：一般情况下shell脚本正常执行完毕，getExitStatus方法返回0。
此方法通过远程命令取得Exit Code/status。但并不是每个server设计时都会返回这个值，如果没有则会返回null。
在调用getExitStatus时，要先调用WaitForCondition方法，通过ChannelCondition.java接口的定义可以看到每个条件的具体含义。见以下代码：
ChannelCondition.java
 

package ch.ethz.ssh2;

/** *//**
 * Contains constants that can be used to specify what conditions to wait for on
 * a SSH-2 channel (e.g., represented by a {@link Session}).
 *
 * @see Session#waitForCondition(int, long)
 *
 * @author Christian Plattner, [email protected]
 * @version $Id: ChannelCondition.java,v 1.6 2006/08/11 12:24:00 cplattne Exp $
 */

public abstract interface ChannelCondition
{
    /** *//**
     * A timeout has occurred, none of your requested conditions is fulfilled.
     * However, other conditions may be true - therefore, NEVER use the "=="
     * operator to test for this (or any other) condition. Always use
     * something like <code>((cond & ChannelCondition.CLOSED) != 0)</code>.
     */
    public static final int TIMEOUT = 1;

    /** *//**
     * The underlying SSH-2 channel, however not necessarily the whole connection,
     * has been closed. This implies <code>EOF</code>. Note that there may still
     * be unread stdout or stderr data in the local window, i.e, <code>STDOUT_DATA</code>
     * or/and <code>STDERR_DATA</code> may be set at the same time.
     */
    public static final int CLOSED = 2;

    /** *//**
     * There is stdout data available that is ready to be consumed.
     */
    public static final int STDOUT_DATA = 4;

    /** *//**
     * There is stderr data available that is ready to be consumed.
     */
    public static final int STDERR_DATA = 8;

    /** *//**
     * EOF on has been reached, no more _new_ stdout or stderr data will arrive
     * from the remote server. However, there may be unread stdout or stderr
     * data, i.e, <code>STDOUT_DATA</code> or/and <code>STDERR_DATA</code>
     * may be set at the same time.
     */
    public static final int EOF = 16;

    /** *//**
     * The exit status of the remote process is available.
     * Some servers never send the exist status, or occasionally "forget" to do so.
     */
    public static final int EXIT_STATUS = 32;

    /** *//**
     * The exit signal of the remote process is available.
     */
    public static final int EXIT_SIGNAL = 64;

}

当我们把myTest.sh修改为如下内容：
 

echo $ 1  $ 2  $ #
print  $ 1

由于我使用的linux机器上没有print命令，所以print $1会报错：command not found。

接下来再让我们执行一下，看看控制台的结果：
 

outStr = java Know  3
outErr =/ sshapp / myshell / myTest.sh: line  2 : print: command not found
127

此时shell脚本出现错误，getExitStatus方法返回127.

在实际应用中，可以将outStr和outErr记录到日志中，以便维护人员查看shell的执行情况，
而getExitStatus的返回值，可以认为是此次执行是否OK的标准。

其他代码请看\ganymed-ssh2-build210\examples\下的例子吧。