Remove all non null values that are returned (#813)

* Remove all non null values that are returned

#630

* Trigger ECA validation

* Update basyx.submodelregistry/basyx.submodelregistry-service/src/main/java/org/eclipse/digitaltwin/basyx/submodelregistry/service/configuration/WebMvcConfig.java

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Update changes based on the review

* Fix JSON configuration and remove unnecessary custom beans

- Removed custom MappingJackson2HttpMessageConverter bean
- Removed unnecessary WebMvcConfigurer
- Updated ObjectMapper bean to use existing Jackson2ObjectMapperBuilder with:
  - NON_NULL serialization inclusion
  - Disabled WRITE_DATES_AS_TIMESTAMPS
- Root cause: @EnableWebMvc was overriding Spring Boot defaults, breaking message converters and static resources
- Now relies on Spring Boot auto-configuration for converters and static resources

refs #640

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: geso02

basyx.aasregistry/basyx.aasregistry-service/src/main/java/org/eclipse/digitaltwin/basyx/aasregistry/service/configuration/RestConfiguration.java

@@ -35,29 +35,18 @@
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.format.FormatterRegistry;
 import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
-import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
-import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
-import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.databind.SerializationFeature;
 
 @Configuration
-@EnableWebMvc
 public class RestConfiguration extends BaSyxHTTPConfiguration implements WebMvcConfigurer {
 
 	@Bean
 	public LocationBuilder locationBuilder() {
 		return new DefaultLocationBuilder();
 	}
 
-	@Bean
-	public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter() {
-		Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder().serializationInclusion(JsonInclude.Include.NON_NULL);
-		builder.featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
-		return new MappingJackson2HttpMessageConverter(builder.build());
-	}
-
 	@Bean
 	public CorsPathPatternProvider getAasRegistryServiceCorsUrlProvider() {
 		return new CorsPathPatternProvider("/shell-descriptors/**");
@@ -72,6 +61,11 @@ public CorsPathPatternProvider getAasRegistryServiceDescriptionCorsUrlProvider()
 	public SerializationExtension getExtension() {
 		return new Aas4JHTTPSerializationExtension();
 	}
+	
+	@Bean
+	public SerializationExtension getDisableExtension() {
+		return builder -> builder.featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+	}
 
 	@Override
 	public void addFormatters(FormatterRegistry registry) {

basyx.aasregistry/basyx.aasregistry-service/src/main/java/org/eclipse/digitaltwin/basyx/aasregistry/service/events/RegistryEventLogSink.java

@@ -42,7 +42,6 @@
 public class RegistryEventLogSink implements RegistryEventSink {
 
 	@Autowired
-	@Qualifier("mappingJackson2HttpMessageConverter")
 	private MappingJackson2HttpMessageConverter converter;
 
 	@Override

basyx.submodelregistry/basyx.submodelregistry-service/src/main/java/org/eclipse/digitaltwin/basyx/submodelregistry/service/configuration/RestConfiguration.java

@@ -40,7 +40,6 @@
 import com.fasterxml.jackson.databind.SerializationFeature;
 
 @Configuration
-@EnableWebMvc
 public class RestConfiguration extends BaSyxHTTPConfiguration  {
 
 	@Bean
@@ -52,14 +51,7 @@ public LocationBuilder submodelRegistryLocationBuilder() {
 	public RestTemplate submodelRegistryRestTemplate() {
 		return new RestTemplate();
 	}
-
-	@Bean
-	public MappingJackson2HttpMessageConverter submodelRegistryMappingJackson2HttpMessageConverter() {
-		Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder().serializationInclusion(JsonInclude.Include.NON_NULL);
-		builder.featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
-		return new MappingJackson2HttpMessageConverter(builder.build());
-	}
-
+	
 	@Bean
 	public CorsPathPatternProvider getSubmodelRegistryServiceCorsUrlProvider() {
 		return new CorsPathPatternProvider("/submodel-descriptors/**");
@@ -74,4 +66,9 @@ public CorsPathPatternProvider getSubmodelRegistryServiceDescriptionCorsUrlProvi
 	public SerializationExtension getSubmodelRegistryExtension() {
 		return new Aas4JHTTPSerializationExtension();
 	}
+	
+	@Bean
+	public SerializationExtension getDisableExtension() {
+		return builder -> builder.featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+	}
 }

basyx.submodelregistry/basyx.submodelregistry-service/src/main/java/org/eclipse/digitaltwin/basyx/submodelregistry/service/events/RegistryEventLogSink.java

@@ -42,7 +42,6 @@
 public class RegistryEventLogSink implements RegistryEventSink {
 
 	@Autowired
-	@Qualifier("submodelRegistryMappingJackson2HttpMessageConverter")
 	private MappingJackson2HttpMessageConverter converter;
 
 	@Override