[{
"USERGROUPNAME": "Universal",
"ACCESSNAME": "*"
}]

这段json字符串是正确的格式，我创建对应的object后，测试代码：
String subJsonStringValue = "[{"USERGROUPNAMES":"Universal","ACCESSNAMES":"*"}]";
List userGroupDetailList = JSON.parseArray(subJsonStringValue, UserGroup.class);
提示无法转换，
错误信息：
default constructor not found. class com.amat.model.UserGroup

@DaTa
public class UserGroup {
private String userGroupNames;
private String accessNames;
}