Values in a spring.data.cassandra.config file can't override some defaults defined in CassandraProperties

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

@@ -23,7 +23,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.function.Supplier;
-import java.util.stream.Collectors;
 
 import javax.net.ssl.SSLContext;
 
@@ -126,7 +125,10 @@ private Config cassandraConfiguration(CassandraProperties properties) {
 
 	private Config applyDefaultFallback(Config config) {
 		ConfigFactory.invalidateCaches();
-		return ConfigFactory.defaultOverrides().withFallback(config).withFallback(ConfigFactory.defaultReference())
+		return ConfigFactory.defaultOverrides()
+				.withFallback(config)
+				.withFallback(mapConfig(CassandraProperties.defaults()))
+				.withFallback(ConfigFactory.defaultReference())
 				.resolve();
 	}
 
@@ -153,10 +155,10 @@ private Config mapConfig(CassandraProperties properties) {
 		mapPoolingOptions(properties, options);
 		mapRequestOptions(properties, options);
 		mapControlConnectionOptions(properties, options);
-		map.from(mapContactPoints(properties))
+		map.from(mapContactPoints(properties)).whenNonNull()
 				.to((contactPoints) -> options.add(DefaultDriverOption.CONTACT_POINTS, contactPoints));
-		map.from(properties.getLocalDatacenter()).to(
-				(localDatacenter) -> options.add(DefaultDriverOption.LOAD_BALANCING_LOCAL_DATACENTER, localDatacenter));
+		map.from(properties.getLocalDatacenter()).whenHasText()
+				.to((localDatacenter) -> options.add(DefaultDriverOption.LOAD_BALANCING_LOCAL_DATACENTER, localDatacenter));
 		return options.build();
 	}
 
@@ -210,8 +212,9 @@ private void mapControlConnectionOptions(CassandraProperties properties, Cassand
 	}
 
 	private List<String> mapContactPoints(CassandraProperties properties) {
-		return properties.getContactPoints().stream()
-				.map((candidate) -> formatContactPoint(candidate, properties.getPort())).collect(Collectors.toList());
+		List<String> contactPoints = properties.getContactPoints();
+		return (contactPoints == null) ? null : contactPoints.stream()
+				.map((candidate) -> formatContactPoint(candidate, properties.getPort())).toList();
 	}
 
 	private String formatContactPoint(String candidate, int port) {

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

@@ -38,6 +38,16 @@
 @ConfigurationProperties(prefix = "spring.data.cassandra")
 public class CassandraProperties {
 
+	static CassandraProperties defaults() {
+		var properties = new CassandraProperties();
+
+		properties.setContactPoints(new ArrayList<>(Collections.singleton("127.0.0.1:9042")));
+		properties.setCompression(Compression.NONE);
+		properties.getControlconnection().setTimeout(Duration.ofSeconds(5));
+
+		return properties;
+	}
+
 	/**
 	 * Location of the configuration file to use.
 	 */
@@ -57,7 +67,7 @@ public class CassandraProperties {
 	 * Cluster node addresses in the form 'host:port', or a simple 'host' to use the
 	 * configured port.
 	 */
-	private final List<String> contactPoints = new ArrayList<>(Collections.singleton("127.0.0.1:9042"));
+	private List<String> contactPoints;
 
 	/**
 	 * Port to use if a contact point does not specify one.
@@ -83,7 +93,7 @@ public class CassandraProperties {
 	/**
 	 * Compression supported by the Cassandra binary protocol.
 	 */
-	private Compression compression = Compression.NONE;
+	private Compression compression;
 
 	/**
 	 * Schema action to take at startup.
@@ -143,6 +153,10 @@ public List<String> getContactPoints() {
 		return this.contactPoints;
 	}
 
+	public void setContactPoints(List<String> contactPoints) {
+		this.contactPoints = contactPoints;
+	}
+
 	public int getPort() {
 		return this.port;
 	}
@@ -266,7 +280,7 @@ public static class Request {
 		/**
 		 * How many rows will be retrieved simultaneously in a single network round-trip.
 		 */
-		private int pageSize;
+		private Integer pageSize;
 
 		private final Throttler throttler = new Throttler();
 
@@ -294,7 +308,7 @@ public void setSerialConsistency(DefaultConsistencyLevel serialConsistency) {
 			this.serialConsistency = serialConsistency;
 		}
 
-		public int getPageSize() {
+		public Integer getPageSize() {
 			return this.pageSize;
 		}
 
@@ -347,7 +361,7 @@ public static class Controlconnection {
 		/**
 		 * Timeout to use for control queries.
 		 */
-		private Duration timeout = Duration.ofSeconds(5);
+		private Duration timeout;
 
 		public Duration getTimeout() {
 			return this.timeout;
@@ -370,17 +384,17 @@ public static class Throttler {
 		 * Maximum number of requests that can be enqueued when the throttling threshold
 		 * is exceeded.
 		 */
-		private int maxQueueSize;
+		private Integer maxQueueSize;
 
 		/**
 		 * Maximum number of requests that are allowed to execute in parallel.
 		 */
-		private int maxConcurrentRequests;
+		private Integer maxConcurrentRequests;
 
 		/**
 		 * Maximum allowed request rate.
 		 */
-		private int maxRequestsPerSecond;
+		private Integer maxRequestsPerSecond;
 
 		/**
 		 * How often the throttler attempts to dequeue requests. Set this high enough that
@@ -397,23 +411,23 @@ public void setType(ThrottlerType type) {
 			this.type = type;
 		}
 
-		public int getMaxQueueSize() {
+		public Integer getMaxQueueSize() {
 			return this.maxQueueSize;
 		}
 
 		public void setMaxQueueSize(int maxQueueSize) {
 			this.maxQueueSize = maxQueueSize;
 		}
 
-		public int getMaxConcurrentRequests() {
+		public Integer getMaxConcurrentRequests() {
 			return this.maxConcurrentRequests;
 		}
 
 		public void setMaxConcurrentRequests(int maxConcurrentRequests) {
 			this.maxConcurrentRequests = maxConcurrentRequests;
 		}
 
-		public int getMaxRequestsPerSecond() {
+		public Integer getMaxRequestsPerSecond() {
 			return this.maxRequestsPerSecond;
 		}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/cassandra/CassandraAutoConfigurationTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.cassandra;
 
 import java.time.Duration;
+import java.util.List;
 
 import com.datastax.oss.driver.api.core.CqlIdentifier;
 import com.datastax.oss.driver.api.core.CqlSession;
@@ -28,6 +29,7 @@
 import com.datastax.oss.driver.internal.core.session.throttling.ConcurrencyLimitingRequestThrottler;
 import com.datastax.oss.driver.internal.core.session.throttling.PassThroughRequestThrottler;
 import com.datastax.oss.driver.internal.core.session.throttling.RateLimitingRequestThrottler;
+import org.assertj.core.api.SoftAssertions;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
@@ -244,6 +246,44 @@ void driverConfigLoaderWithConfigComplementSettings() {
 				});
 	}
 
+	@Test // gh-31025
+	void driverConfigLoaderWithConfigOverridesDefaults() {
+		String configLocation = "org/springframework/boot/autoconfigure/cassandra/override-defaults.conf";
+		this.contextRunner.withPropertyValues("spring.data.cassandra.config=" + configLocation).run((context) -> {
+				assertThat(context).hasSingleBean(DriverConfigLoader.class);
+
+				SoftAssertions softly = new SoftAssertions();
+
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getString(DefaultDriverOption.SESSION_NAME)).isEqualTo("advanced session");
+
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getDuration(DefaultDriverOption.REQUEST_TIMEOUT)).isEqualTo(Duration.ofSeconds(2)); // default
+
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getStringList(DefaultDriverOption.CONTACT_POINTS)).isEqualTo(List.of("1.2.3.4:5678"));
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getBoolean(DefaultDriverOption.RESOLVE_CONTACT_POINTS)).isFalse();
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getInt(DefaultDriverOption.REQUEST_PAGE_SIZE)).isEqualTo(11);
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getString(DefaultDriverOption.LOAD_BALANCING_LOCAL_DATACENTER)).isEqualTo("datacenter1");
+
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getInt(DefaultDriverOption.REQUEST_THROTTLER_MAX_CONCURRENT_REQUESTS)).isEqualTo(22);
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getInt(DefaultDriverOption.REQUEST_THROTTLER_MAX_REQUESTS_PER_SECOND)).isEqualTo(33);
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getInt(DefaultDriverOption.REQUEST_THROTTLER_MAX_QUEUE_SIZE)).isEqualTo(44);
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getDuration(DefaultDriverOption.CONTROL_CONNECTION_TIMEOUT)).isEqualTo(Duration.ofMillis(5555));
+				softly.assertThat(context.getBean(DriverConfigLoader.class).getInitialConfig().getDefaultProfile()
+						.getString(DefaultDriverOption.PROTOCOL_COMPRESSION)).isEqualTo("SNAPPY");
+
+				softly.assertAll();
+		});
+	}
+
 	@Test
 	void driverConfigLoaderWithConfigCreateProfiles() {
 		String configLocation = "org/springframework/boot/autoconfigure/cassandra/profiles.conf";

spring-boot-project/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/cassandra/override-defaults.conf

@@ -0,0 +1,20 @@
+datastax-java-driver {
+  basic {
+    session-name = advanced session
+    load-balancing-policy {
+      local-datacenter = datacenter1
+    }
+    request.page-size = 11
+    contact-points = [ "1.2.3.4:5678" ]
+  }
+  advanced {
+    throttler {
+      max-concurrent-requests = 22
+      max-requests-per-second = 33
+      max-queue-size = 44
+    }
+    control-connection.timeout = 5555
+    protocol.compression = SNAPPY
+    resolve-contact-points = false
+  }
+}