下文所述的两个试验在Linux AS3和Jdk5上测试通过。
一、在java程序中跨平台运行shell命令或者脚本，并获得其输出
import java.io.BufferedReader;
import java.io.InputStreamReader;

public class TestCMD {

    /**
    * @param args
    */
    public static void main(String[] args) {
        try {
            Process child = null;
            String systemType = System.getProperty("os.name");
            if (systemType.equals("Linux")) {
                System.out.println("Linux OS!");
                child = Runtime.getRuntime().exec("jmap -h", null, null);
            } else if (systemType.indexOf("Windows") > -1) {
                // If the os is windows, you need to add cmd before command.
                System.out.println("Windows OS!");
                child = Runtime.getRuntime().exec("cmd java -version", null,
                        null);
            }

            // Get the input stream and read from it
            BufferedReader in = new BufferedReader(new InputStreamReader(child
                    .getInputStream()));

            String c = null;
            while ((c = in.readLine()) != null) {
                System.out.println(c);
            }
            in.close();
            return;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

二、推广：根据某个进程特殊的tag获得其进程ID
import java.io.BufferedReader;
import java.io.InputStreamReader;

/*
* @(#)TestGetPid.java 2008-5-21
*
* Copyright (c) 2008
* All rights reserved.
* $
*/

/**
* <strong>Purpose:</strong><br>
* TODO.
*
* @version 1.0.1 2008-5-21<br>
* @author AxisThinker<br>
* @email ddjoke@163.com
*/
public class TestGetPid {

    /**
    * @param args
    */
    public static void main(String[] args) {
        try {
            Process child = null;
            String systemType = System.getProperty("os.name");
            if (systemType.equals("Linux")) {
                // If the os is linux, you need to add bash before command.
                System.out.println("Support Linux os!");
                child = Runtime.getRuntime().exec("ps -Af", null, null);
            } else if (systemType.indexOf("Windows") > -1) {
                System.out.println("Not support windows!");
            }

            // Get the input stream and read from it
            BufferedReader in = new BufferedReader(new InputStreamReader(child
                    .getInputStream()));

            String c = null;
            // Only get the first line of bash's output.
            while ((c = in.readLine()) != null) {
                //这里this.name=GOS.CORE就是我要找的某个进程的特殊tag，各位可以换成你想找的进程
                if (c.contains("this.name=GOS.CORE")) {
                    c = c.substring(c.indexOf(" "), c.length());
                    c = c.trim();
                    c = c.substring(0, c.indexOf(" "));
                    c = c.trim();
                    System.out.println(c);
                    break;
                }
            }
            in.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

三： 高级应用： 通过ssh的配置，远程调用其他主机的命令，并在本地得到其输出，中间不用输入密码
第一步：需要配置ssh。配置方法简要如下：
    首先，例如我想用本地的lxy账户登陆远程节点A的lxy1账户，那么首先进入本地/home/lxy目录，在这个目录下有一个隐藏目录.ssh，进入这个目录，利用ssh-keygen命令来生成本用户的公私钥对，可以利用-t参数来指定生成方法：一般用rsa方法。此时，会要求你输入key的密码，直接回车就可以。如果你输的话，就一定要输入4位以上的密码，而且，以后你用ssh的时候就要输入这个密码。所以，建议不输入。
    然后会在.ssh目录下生成两个文件，例如id_rsa和id_rsa.pub，利用vi拷贝id_rsa.pub中的内容到远程节点A的lxy1账户目录下的.ssh目录里面的authorized_keys文件里。这样，以后你在本地以lxy用户身份利用ssh命令用节点A的lxy1账号登陆A节点，就不用再输入密码了。而且，执行：ssh lxy1@A ls 就能直接返回远程节点A的/home/lxy1/目录结构，不用输入密码。

第二步：编写程序
import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
*Author: AxisThinker
*Email: ddjoke@163.com
*/
public class TestCMD {

    /**
    * @param args
    */
    public static void main(String[] args) {
        try {
            Process child = null;
            String systemType = System.getProperty("os.name");
            if (systemType.equals("Linux")) {
                System.out.println("Linux OS!");
                child = Runtime
                        .getRuntime()
                        .exec(
                                "ssh gos@10.61.0.215 bash -c \"$JAVA_HOME/bin/jmap -heap 10191\"");
                   //这里有两点需要注意：第一你要运行的命令需要用bash -c引导。这样是告诉shell，后面的是一条指令，并且要在远端解释环境变量；二是要用转义\"来讲这个指令包起来，否则的话远端会以为jmap是一个指令，-heap是一个指令等等。
            } else if (systemType.indexOf("Windows") > -1) {
                // If the os is windows, you need to add cmd before command.
                System.out.println("Windows OS!");
                child = Runtime.getRuntime().exec(
                        new String[] { "cmd", "java", "-version" }, null, null);
            }

            // Get the input stream and read from it
            BufferedReader in = new BufferedReader(new InputStreamReader(child
                    .getInputStream()));

            String c = null;
            while ((c = in.readLine()) != null) {
                System.out.println(c);
                if (c.equals("XXX")) {//这里比较重要，由于c = in.readLine()容易发生阻塞，所以，这里用比较土的办法来解决，根据最后一行的返回值来决定其是否退出。
                    break;
                }
            }
            in.close();
            return;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}