Spring Security OAuth2客户端报错@ConditionalOnProperty (security.oauth2.client.grant-type=client_credentials) did not find property ‘grant-type’

这几天在研究Spring Security OAuth2的客户端，但是各种报错，具体报错如下：

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APPLICATION FAILED TO START
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Description:

Parameter 1 of method oauth2RestTemplate in com.sso.ssoclient.Oauth2ClientConfig required a bean of type 'org.springframework.security.oauth2.client.resource.OAuth2ProtectedResourceDetails' that could not be found.

The following candidates were found but could not be injected:
- Bean method 'oauth2RemoteResource' in 'OAuth2RestOperationsConfiguration.SingletonScopedConfiguration' not loaded because AnyNestedCondition 0 matched 2 did not; NestedCondition on OAuth2RestOperationsConfiguration.ClientCredentialsCondition.NoWebApplication @ConditionalOnWebApplication found 'session' scope and did not find reactive web application classes; NestedCondition on OAuth2RestOperationsConfiguration.ClientCredentialsCondition.ClientCredentialsConfigured @ConditionalOnProperty (security.oauth2.client.grant-type=client_credentials) did not find property 'grant-type'

Action:

Consider revisiting the entries above or defining a bean of type 'org.springframework.security.oauth2.client.resource.OAuth2ProtectedResourceDetails' in your configuration.

看这个报错信息，好像是说OAuth2ProtectedResourceDetails这个bean没有，然后我看了下代码，在@EnableOAuth2Client配置里有一个oauth2RestTemplate函数里用到了OAuth2ProtectedResourceDetails这个参数，我点到源码里发现这是一个interface，不是一个实现类，所以感觉是没有找到对应的实现类才报的错，难道需要我们自己来实现吗？感觉应该不用才对啊，后来在网上发现有的在配置文件里配置了OAuth2的相关配置，想到是不是因为没有配置引起的。

于是把下面的配置加上后工程就能正常启动了。

security:
  oauth2:
    resource:
      userInfoUri: http://localhost:8901/auth/user
    client:
      grant-type: client_credentials

所以报错信息里找不到的grant-type其实是在配置文件里配置的。。