getCredential method
Implementation
Future<OSSCredential> getCredential() async {
OSSCredential? validCredential;
if (_cachedCredential == null) {
_cachedCredential = await _fetchCredential();
} else {
if (_checkExpire(_cachedCredential!.expiration)) {
_cachedCredential = await _fetchCredential();
}
}
validCredential = _cachedCredential;
if (validCredential == null) {
return Future.error(HttpException('获取sts token失败'));
}
return validCredential;
}