Adopt purely name-based user-override contract for EventHubClientBuilder

Remove the custom OnMissingUserDefinedEventHubClientBuilderCondition and rely solely on @ConditionalOnMissingBean(name = EVENT_HUB_CLIENT_BUILDER_BEAN_NAME). The override contract is now uniformly name-based: to replace the auto-configured root builder (and have shared EventHubConsumerClient/EventHubProducerClient pick up the override) the user must register their bean under springCloudAzureEventHubsClientBuilder. A user-supplied bean under any other name no longer suppresses the auto-configured root and is not wired into the shared clients. Update userDefinedEventHubsClientBuilderProvidedShouldNotAutoconfigure to register under the reserved name, add a new userDefinedEventHubsClientBuilderUnderCustomNameShouldNotSuppressAutoconfigure asserting the new coexistence behavior, and tighten the CHANGELOG breaking-change entry.

Author: rujche

sdk/spring/CHANGELOG.md

@@ -11,7 +11,7 @@ This section includes changes in `spring-cloud-azure-autoconfigure` module.
 - AAD resource server now requires `spring.cloud.azure.active-directory.profile.tenant-id` to be set to a specific (non-reserved) tenant ID. Empty string, `common`, `organizations`, and `consumers` are no longer accepted and will cause application startup to fail with an `IllegalArgumentException`. ([#49033](https://github.com/Azure/azure-sdk-for-java/pull/49033))
 - `AadAuthenticationFilter` now enables explicit audience validation by default. The filter will verify that the JWT's `aud` (audience) claim matches either `spring.cloud.azure.active-directory.credential.client-id` or `spring.cloud.azure.active-directory.app-id-uri`. Tokens issued for other applications will be rejected with `BadJWTException`. This prevents cross-application token reuse and aligns with OAuth2/OIDC security best practices. ([#49033](https://github.com/Azure/azure-sdk-for-java/pull/49033))
 - B2C resource server now requires `spring.cloud.azure.active-directory.b2c.profile.tenant-id` to be set to a specific (non-reserved) tenant ID. Empty string, `common`, `organizations`, and `consumers` are no longer accepted. In addition, default token validation is hardened to enforce tenant-bound `tid`, stricter `aud` validation, and B2C-only trusted issuers. ([#49252](https://github.com/Azure/azure-sdk-for-java/pull/49252))
-- Event Hubs shared consumer/producer auto-configuration now wires the root `EventHubClientBuilder` by bean name (`springCloudAzureEventHubsClientBuilder`) instead of by type. Users who provide their own `EventHubClientBuilder` bean and want it to be injected into the auto-configured shared `EventHubConsumerClient`/`EventHubProducerClient` must register it under that bean name; a user-supplied builder under a different name will still suppress the auto-configured root builder, but will not be wired into the shared clients. ([#49245](https://github.com/Azure/azure-sdk-for-java/issues/49245))
+- Event Hubs auto-configuration now identifies the root `EventHubClientBuilder` by bean name (`springCloudAzureEventHubsClientBuilder`) instead of by type. To override the auto-configured root builder (and have shared `EventHubConsumerClient`/`EventHubProducerClient` use your bean), register the bean under the name `springCloudAzureEventHubsClientBuilder`. A user-supplied `EventHubClientBuilder` bean under a different name will no longer suppress the auto-configured root builder and will not be wired into the shared clients. ([#49245](https://github.com/Azure/azure-sdk-for-java/issues/49245))
 
 #### Bugs Fixed
 

sdk/spring/spring-cloud-azure-autoconfigure/src/main/java/com/azure/spring/cloud/autoconfigure/implementation/eventhubs/AzureEventHubsClientBuilderConfiguration.java

@@ -19,7 +19,6 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnExpression;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 
@@ -43,7 +42,6 @@ class AzureEventHubsClientBuilderConfiguration {
 
     @Bean(EVENT_HUB_CLIENT_BUILDER_BEAN_NAME)
     @ConditionalOnMissingBean(name = EVENT_HUB_CLIENT_BUILDER_BEAN_NAME)
-    @Conditional(OnMissingUserDefinedEventHubClientBuilderCondition.class)
     EventHubClientBuilder eventHubClientBuilder(@Qualifier(EVENT_HUB_CLIENT_BUILDER_FACTORY_BEAN_NAME)
                                                     EventHubClientBuilderFactory factory) {
         return factory.build();

sdk/spring/spring-cloud-azure-autoconfigure/src/main/java/com/azure/spring/cloud/autoconfigure/implementation/eventhubs/OnMissingUserDefinedEventHubClientBuilderCondition.java

@@ -6,6 +6,7 @@
 import com.azure.data.appconfiguration.ConfigurationClientBuilder;
 import com.azure.messaging.eventhubs.EventHubClientBuilder;
 import com.azure.spring.cloud.autoconfigure.implementation.TestBuilderCustomizer;
+import com.azure.spring.cloud.autoconfigure.implementation.context.AzureContextUtils;
 import com.azure.spring.cloud.autoconfigure.implementation.context.properties.AzureGlobalProperties;
 import com.azure.spring.cloud.autoconfigure.implementation.eventhubs.properties.AzureEventHubsConnectionDetails;
 import com.azure.spring.cloud.core.provider.connectionstring.StaticConnectionStringProvider;
@@ -93,10 +94,24 @@ void userDefinedEventHubsClientBuilderProvidedShouldNotAutoconfigure() {
                 "spring.cloud.azure.eventhubs.connection-string=" + String.format(CONNECTION_STRING_FORMAT, "test-namespace")
             )
             .withBean(AzureGlobalProperties.class, AzureGlobalProperties::new)
-            .withBean("user-defined-builder", EventHubClientBuilder.class, EventHubClientBuilder::new)
+            .withBean(AzureContextUtils.EVENT_HUB_CLIENT_BUILDER_BEAN_NAME, EventHubClientBuilder.class, EventHubClientBuilder::new)
             .run(context -> {
                 assertThat(context).hasSingleBean(EventHubClientBuilder.class);
-                assertThat(context).hasBean("user-defined-builder");
+                assertThat(context).hasBean(AzureContextUtils.EVENT_HUB_CLIENT_BUILDER_BEAN_NAME);
+            });
+    }
+
+    @Test
+    void userDefinedEventHubsClientBuilderUnderCustomNameShouldNotSuppressAutoconfigure() {
+        this.contextRunner
+            .withPropertyValues(
+                "spring.cloud.azure.eventhubs.connection-string=" + String.format(CONNECTION_STRING_FORMAT, "test-namespace")
+            )
+            .withBean(AzureGlobalProperties.class, AzureGlobalProperties::new)
+            .withBean("user-defined-builder", EventHubClientBuilder.class, EventHubClientBuilder::new)
+            .run(context -> {
+                assertThat(context).getBeanNames(EventHubClientBuilder.class)
+                    .containsExactlyInAnyOrder("user-defined-builder", AzureContextUtils.EVENT_HUB_CLIENT_BUILDER_BEAN_NAME);
             });
     }