如何用代码检测一个软件是否被授权了root权限

1. private boolean hasRoot() {
2. char[] arrayOfChar = new char[1024];
3. try {
4. int j = new InputStreamReader(Runtime.getRuntime().exec("su -c ls")
5.    .getErrorStream()).read(arrayOfChar);
6. if (j == -1) {
7. return true;
8. }
9. } catch (IOException e) {
10. }
11. return false;...