不弹出对话框，检测root权限

/** 判断手机是否root，不弹出root请求框 */
public static boolean isRoot() {
    String binPath = "/system/bin/su";
    String xBinPath = "/system/xbin/su";
    if (new File(binPath).exists() && isExecutable(binPath)) return true;
    return new File(xBinPath).exists() && isExecutable(xBinPath);
}
  private static boolean isExecutable(String filePath) {
     Process p = null;
     try {
         p = Runtime.getRuntime().exec("ls -l " + filePath);            // 获取返回内容
         BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
         String str = in.readLine();
         LLogUtils.i(str);
         if (str != null && str.length() >;= 4) {
             char flag = str.charAt(3);
             if (flag == 's' || flag == 'x') return true;
         }
     } catch (IOException e) {
         e.printStackTrace();
     } finally {
         if (p != null) {
             p.destroy();
         }
     }
     return false;
 }