Java执行操作系统命令

从网上学来的方法，sample:

        try {            String[] cmd = new String[] { System.getenv("HOMEPATH")    + "/test.bat" };            Process ps = Runtime.getRuntime().exec(cmd);            BufferedReader br = new BufferedReader(new InputStreamReader(ps.getInputStream()));            StringBuffer sb = new StringBuffer();            String line;            while ((line = br.readLine()) != null) {                sb.append(line).append("\n");            }            String result = sb.toString();            System.out.println(result);        } catch (Exception e) {            e.printStackTrace();        }