apk(java)应用程序调用系统命令

private void LsInfo()    {    try {    //String[] cmd = new String[]{"sh","-c","ls -l"};    String[] cmd = new String[]{"sh","-c","ls -l"};    Process ps = Runtime.getRuntime().exec(cmd);//////////////////////////////第一种，以   byte[] buf方式将logcat 出来的信息保存在/data/data/com.logcat.logcat目录下 lsll.txt====================    //        FileOutputStream fileOutputStream = null;//        File file = new File("/data/data/com.logcat.logcat", "lsll.txt");//        fileOutputStream = new FileOutputStream(file);//    InputStream is = ps.getInputStream();//    int ch=0;//    byte[] buf = new byte[1024];//    do {//ch = is.read(buf);////Log.v("===========logcat=======", "=====================buf===============start"+ buf);//if (ch <= 0)//break;//fileOutputStream.write(buf, 0, ch);////} while (true);//is.close();//fileOutputStream.close();////////////////////////第一种end/////////////////////////////第二种，直接返回其结果字符串给应用使用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);////////////////////////第二种end    } catch (Exception e) {    e.printStackTrace();    }    }