#1252 - Polishing.

We now make sure that BeanPostProcessors that are exposed consume their dependencies via ObjectFactory instances to avoid the need to prematurely trigger bean instantiation in the BeanPostProcessor detection phase. Marked the direct dependencies of the post processors as lazy, as the post processor only do actual work if beans of a particular type are available in the ApplicationContext. In case they aren't we don't even need to instantiate the downstream dependencies of the processors.

Avoid proxying of configuration classes where possible.

Related pull request: #1251.

Author: odrotbohm

src/main/java/org/springframework/hateoas/config/EntityLinksConfiguration.java

@@ -29,7 +29,7 @@
  * @author Greg Turnquist
  * @author Oliver Gierke
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 class EntityLinksConfiguration {
 
 	@Bean

src/main/java/org/springframework/hateoas/config/HateoasConfiguration.java

@@ -59,7 +59,7 @@
  * @soundtrack Elephants Crossing - Wait (Live at Stadtfest Dresden)
  * @since 0.19
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 @EnablePluginRegistries({ LinkDiscoverer.class })
 public class HateoasConfiguration {
 

src/main/java/org/springframework/hateoas/config/RestTemplateHateoasConfiguration.java

@@ -18,9 +18,11 @@
 import lombok.RequiredArgsConstructor;
 
 import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.lang.NonNull;
 import org.springframework.web.client.RestTemplate;
 
@@ -30,16 +32,17 @@
  * @author Greg Turnquist
  * @author Oliver Drotbohm
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 class RestTemplateHateoasConfiguration {
 
 	@Bean
 	static HypermediaRestTemplateBeanPostProcessor hypermediaRestTemplateBeanPostProcessor(
-			HypermediaRestTemplateConfigurer configurer) {
+			ObjectFactory<HypermediaRestTemplateConfigurer> configurer) {
 		return new HypermediaRestTemplateBeanPostProcessor(configurer);
 	}
 
 	@Bean
+	@Lazy
 	HypermediaRestTemplateConfigurer hypermediaRestTemplateConfigurer(WebConverters converters) {
 		return new HypermediaRestTemplateConfigurer(converters);
 	}
@@ -54,7 +57,7 @@ HypermediaRestTemplateConfigurer hypermediaRestTemplateConfigurer(WebConverters
 	@RequiredArgsConstructor
 	static class HypermediaRestTemplateBeanPostProcessor implements BeanPostProcessor {
 
-		private final HypermediaRestTemplateConfigurer configurer;
+		private final ObjectFactory<HypermediaRestTemplateConfigurer> configurer;
 
 		/*
 		 * (non-Javadoc)
@@ -64,11 +67,9 @@ static class HypermediaRestTemplateBeanPostProcessor implements BeanPostProcesso
 		@Override
 		public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
 
-			if (!RestTemplate.class.isInstance(bean)) {
-				return bean;
-			}
-
-			return this.configurer.registerHypermediaTypes((RestTemplate) bean);
+			return !RestTemplate.class.isInstance(bean) //
+					? bean
+					: this.configurer.getObject().registerHypermediaTypes((RestTemplate) bean);
 		}
 	}
 }

src/main/java/org/springframework/hateoas/config/WebClientHateoasConfiguration.java

@@ -20,10 +20,12 @@
 import java.util.List;
 
 import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.lang.NonNull;
 import org.springframework.web.reactive.function.client.WebClient;
 
@@ -33,19 +35,21 @@
  * Spring WebFlux HATEOAS configuration.
  *
  * @author Greg Turnquist
- * @since 1.0 TODO: Inspect ApplicationContext -> WebApplicationContext -> WebMVC
+ * @since 1.0
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 class WebClientHateoasConfiguration {
 
 	@Bean
+	@Lazy
 	HypermediaWebClientConfigurer webClientConfigurer(ObjectProvider<ObjectMapper> mapper,
 			List<HypermediaMappingInformation> hypermediaTypes) {
 		return new HypermediaWebClientConfigurer(mapper.getIfAvailable(ObjectMapper::new), hypermediaTypes);
 	}
 
 	@Bean
-	static HypermediaWebClientBeanPostProcessor webClientBeanPostProcessor(HypermediaWebClientConfigurer configurer) {
+	static HypermediaWebClientBeanPostProcessor webClientBeanPostProcessor(
+			ObjectFactory<HypermediaWebClientConfigurer> configurer) {
 		return new HypermediaWebClientBeanPostProcessor(configurer);
 	}
 
@@ -59,7 +63,7 @@ static HypermediaWebClientBeanPostProcessor webClientBeanPostProcessor(Hypermedi
 	@RequiredArgsConstructor
 	static class HypermediaWebClientBeanPostProcessor implements BeanPostProcessor {
 
-		private final HypermediaWebClientConfigurer configurer;
+		private final ObjectFactory<HypermediaWebClientConfigurer> configurer;
 
 		/*
 		 * (non-Javadoc)
@@ -69,11 +73,9 @@ static class HypermediaWebClientBeanPostProcessor implements BeanPostProcessor {
 		@Override
 		public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
 
-			if (WebClient.class.isInstance(bean)) {
-				return this.configurer.registerHypermediaTypes(((WebClient) bean).mutate()).build();
-			}
-
-			return bean;
+			return !WebClient.class.isInstance(bean) //
+					? bean //
+					: this.configurer.getObject().registerHypermediaTypes(((WebClient) bean).mutate()).build();
 		}
 	}
 }

src/main/java/org/springframework/hateoas/config/WebFluxHateoasConfiguration.java

@@ -44,7 +44,7 @@
  * @author Oliver Drotbohm
  * @since 1.0
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 class WebFluxHateoasConfiguration {
 
 	@Bean

src/main/java/org/springframework/hateoas/config/WebMvcEntityLinksConfiguration.java

@@ -29,7 +29,7 @@
  * @author Greg Turnquist
  * @author Oliver Gierke
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 class WebMvcEntityLinksConfiguration extends EntityLinksConfiguration {
 
 	@Bean

src/main/java/org/springframework/hateoas/config/WebMvcHateoasConfiguration.java

@@ -44,7 +44,7 @@
  * @author Greg Turnquist
  * @author Oliver Drotbohm
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 @Import(WebMvcEntityLinksConfiguration.class)
 class WebMvcHateoasConfiguration {
 

src/main/java/org/springframework/hateoas/mediatype/hal/HalMediaTypeConfiguration.java

@@ -40,7 +40,7 @@
  * @author Greg Turnquist
  * @author Oliver Drotbohm
  */
-@Configuration
+@Configuration(proxyBeanMethods = false)
 @RequiredArgsConstructor
 public class HalMediaTypeConfiguration implements HypermediaMappingInformation {