How work with 3rd-party @ConfigurationProperties @Bean?

I use IntellijIdea and gradle. Gradle config:

...
apply plugin: 'propdeps'
apply plugin: 'propdeps-idea'
apply plugin: 'propdeps-maven'
buildscript {
    repositories {
        maven { url 'http://repo.spring.io/plugins-release' }
    }
    dependencies {
        classpath 'org.springframework.build.gradle:propdeps-plugin:0.0.7'
    }
}

compileJava.dependsOn(processResources)
dependencies {
    ...
    optional group: 'org.springframework.boot', name: 'spring-boot-configuration-processor', version: '1.4.0.RELEASE'
}

Ok, for creating my own properties i need:

@Component
@ConfigurationProperties("own.prefix")
@Data
public class TestProps {
    public String field;
}

@Configuration
@EnableConfigurationProperties(TestProps.class)
public class AppConf {}

And after i rebuild project spring-boot-configuration-processor genereate new META-INFO, so in application.properties i can use own.prefix.field= and Spring see it.

But what should i do with 3rd party configuration class? Docs http://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html say:

As well as using @ConfigurationProperties to annotate a class, you can also use it on @Bean methods. This can be particularly useful when you want to bind properties to third-party components that are outside of your control.

To configure a bean from the Environment properties, add @ConfigurationProperties to its bean registration:

@ConfigurationProperties(prefix = "foo")
@Bean
public FooComponent fooComponent() {
    ...
}

Any property defined with the foo prefix will be mapped onto that FooComponent bean in a similar manner as the ConnectionProperties example above.

Ok. Lets try. For example I declare bean like in gide (https://spring.io/guides/tutorials/spring-boot-oauth2/):

@Configuration
@EnableOAuth2Sso
public class SocialConfig {

    @Bean
    @ConfigurationProperties("facebook.client")
    OAuth2ProtectedResourceDetails facebook() {
        return new AuthorizationCodeResourceDetails();
    }

    @Bean
    @ConfigurationProperties("facebook.resource")
    ResourceServerProperties facebookResource() {
        return new ResourceServerProperties();
    }
}

But after rebuilding project property facebook.client and facebook.resource do not exist in my application.properties.

Also i tried add SocialConfig.class to

@Configuration
@EnableConfigurationProperties(SocialConfig.class)
public class AppConf {}

After rebuild it still not work. And like this:

@Configuration
@EnableConfigurationProperties
public class AppConf {}

Still the same.

What am I doing wrong? Also sorry for my English :)

What you're doing wrong is that the methods in your @Configuration class are not public. Just add public to facebook and facebookResource and you'll be fine. I've just polished that doc in c4cb8317 and I've submitted a PR to fix the tutorial you were using as a base.

Also the generated metadata were mostly empty since nested objects were not flagged with @NestedConfigurationProperty. I've submitted another pull request to fix that.