Provide control over how a Cassandra Cluster is created

See gh-16702

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cassandra/CassandraAutoConfiguration.java

@@ -40,6 +40,7 @@ import org.springframework.util.StringUtils;
  * @author Phillip Webb
  * @author Eddú Meléndez
  * @author Stephane Nicoll
+ * @auther Steffen F. Qvistgaard
  * @since 1.3.0
  */
 @Configuration(proxyBeanMethods = false)
@@ -47,10 +48,17 @@ import org.springframework.util.StringUtils;
 @EnableConfigurationProperties(CassandraProperties.class)
 public class CassandraAutoConfiguration {
 
+	@Bean
+	@ConditionalOnMissingBean
+	public CassandraClusterFactory cassandraClusterFactory() {
+		return new CassandraClusterFactoryImpl();
+	}
+
 	@Bean
 	@ConditionalOnMissingBean
 	public Cluster cassandraCluster(CassandraProperties properties,
-			ObjectProvider<ClusterBuilderCustomizer> builderCustomizers) {
+			ObjectProvider<ClusterBuilderCustomizer> builderCustomizers,
+			CassandraClusterFactory clusterFactory) {
 		PropertyMapper map = PropertyMapper.get();
 		Cluster.Builder builder = Cluster.builder()
 				.withClusterName(properties.getClusterName())
@@ -71,7 +79,8 @@ public class CassandraAutoConfiguration {
 				.toCall(builder::withoutJMXReporting);
 		builderCustomizers.orderedStream()
 				.forEach((customizer) -> customizer.customize(builder));
-		return builder.build();
+
+		return clusterFactory.build(builder);
 	}
 
 	private QueryOptions getQueryOptions(CassandraProperties properties) {

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cassandra/CassandraClusterFactory.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.cassandra;
+
+import com.datastax.driver.core.Cluster;
+import com.datastax.driver.core.Cluster.Initializer;
+
+/**
+ * Cassandra Cluster Factory Interface.
+ *
+ * This interface allows the default cassandra cluster builder to be overwritten
+ *
+ * @auther Steffen F. Qvistgaard
+ * @since 2.2.0
+ */
+public interface CassandraClusterFactory {
+
+	Cluster build(Initializer initializer);
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cassandra/CassandraClusterFactoryImpl.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.cassandra;
+
+import com.datastax.driver.core.Cluster;
+import com.datastax.driver.core.Cluster.Initializer;
+
+/**
+ * Default Cassandra Cluster Factory Implementation.
+ *
+ * @auther Steffen F. Qvistgaard
+ * @since 2.2.0
+ */
+public class CassandraClusterFactoryImpl implements CassandraClusterFactory {
+
+	@Override
+	public Cluster build(final Initializer initializer) {
+		return Cluster.buildFrom(initializer);
+	}
+
+}