这段代码可以优化（this code below can be optimise）

[凌培勇]

代码位置（file location）：/spring-security-oauth/spring-security-oauth2/src/main/java/org/springframework/security/oauth2/provider/request/DefaultOAuth2RequestFactory.java

1. checkUserScopes 这个方法不需要clientDetails这个参数（the method of checkUserScopes is not need clientDetails parameter）
2. extractScopes 这个方法里clientDetailsService.loadClientByClientId(clientId) 可以放在 if ((scopes == null || scopes.isEmpty())) 方法里，这样当判断为false时，可以减少一次数据库的查询操作。
   clientDetailsService.loadClientByClientId(clientId) in the method of "extractScopes" can be write in the body of " if ((scopes == null || scopes.isEmpty())) " , that can reduce one database query operation

[TDtianzhenjiu]

wether loadClientByClientId is going to query database is determined by ur loadClientByClientId method implication.
you can cache Details