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, [e-mail] 
* @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。 

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