如何用代码检测一个软件是否被授权了root权限

private boolean hasRoot() {
char[] arrayOfChar = new char[1024];
try {
int j = new InputStreamReader(Runtime.getRuntime().exec("su -c ls")
   .getErrorStream()).read(arrayOfChar);
if (j == -1) {
return true;
}
} catch (IOException e) {
}
return false;...