Polishing.

Update javadoc and remove deprecated observation keys.

Original Pull Request: #5020

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/observability/MongoKeyName.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 the original author or authors.
+ * Copyright 2025-present 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.
@@ -31,6 +31,7 @@ import org.springframework.util.StringUtils;
  * {@link KeyValue} and {@link KeyName}.
  *
  * @author Mark Paluch
+ * @since 4.4.9
  */
 record MongoKeyName<C>(String name, boolean required, Function<C, @Nullable Object> valueFunction) implements KeyName {
 
@@ -44,7 +45,7 @@ record MongoKeyName<C>(String name, boolean required, Function<C, @Nullable Obje
 	 * @return
 	 * @param <C>
 	 */
-	public static <C> MongoKeyName<C> required(String name, Function<C, @Nullable Object> valueFunction) {
+	static <C> MongoKeyName<C> required(String name, Function<C, @Nullable Object> valueFunction) {
 		return required(name, valueFunction, Objects::nonNull);
 	}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/observability/MongoObservation.java

@@ -15,16 +15,15 @@
  */
 package org.springframework.data.mongodb.observability;
 
-import static org.springframework.data.mongodb.observability.MongoKeyName.*;
+import static org.springframework.data.mongodb.observability.MongoKeyName.MongoKeyValue;
+import static org.springframework.data.mongodb.observability.MongoKeyName.just;
 
 import io.micrometer.common.docs.KeyName;
 import io.micrometer.observation.docs.ObservationDocumentation;
 
 import org.jspecify.annotations.Nullable;
-
 import org.springframework.util.StringUtils;
 
-import com.mongodb.ConnectionString;
 import com.mongodb.ServerAddress;
 import com.mongodb.connection.ConnectionDescription;
 import com.mongodb.event.CommandEvent;
@@ -86,24 +85,18 @@ enum MongoObservation implements ObservationDocumentation {
 		static MongoKeyName<ServerAddress> NET_PEER_NAME = MongoKeyName.required("net.peer.name", ServerAddress::getHost);
 		static MongoKeyName<ServerAddress> NET_PEER_PORT = MongoKeyName.required("net.peer.port", ServerAddress::getPort);
 
-		static MongoKeyName<ConnectionString> DB_CONNECTION_STRING = MongoKeyName.requiredString("db.connection_string",
-				Object::toString);
-		static MongoKeyName<ConnectionString> DB_USER = MongoKeyName.requiredString("db.user",
-				ConnectionString::getUsername);
-
 		/**
 		 * Observe low cardinality key values for the given {@link MongoHandlerContext}.
 		 *
 		 * @param context the context to contribute from, can be {@literal null} if no context is available.
 		 * @return the key value contributor providing low cardinality key names.
 		 */
-		public static Observer observe(@Nullable MongoHandlerContext context) {
+		static Observer observe(@Nullable MongoHandlerContext context) {
 
 			return Observer.fromContext(context, it -> {
 
 				it.contribute(DB_SYSTEM).contribute(MONGODB_COMMAND, DB_NAME, MONGODB_COLLECTION);
 
-				it.nested(MongoHandlerContext::getConnectionString).contribute(DB_CONNECTION_STRING, DB_USER);
 				it.nested(MongoHandlerContext::getCommandStartedEvent) //
 						.nested(CommandEvent::getConnectionDescription).contribute(MONGODB_CLUSTER_ID) //
 						.nested(ConnectionDescription::getServerAddress) //
@@ -116,9 +109,8 @@ enum MongoObservation implements ObservationDocumentation {
 		 *
 		 * @return the key names for low cardinality keys.
 		 */
-		public static KeyName[] getKeyNames() {
+		static KeyName[] getKeyNames() {
 			return observe(null).toKeyNames();
 		}
 	}
-
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/observability/Observer.java

@@ -30,6 +30,7 @@ import org.jspecify.annotations.Nullable;
  * observability systems.
  *
  * @author Mark Paluch
+ * @since 4.4.9
  */
 class Observer {
 
@@ -40,7 +41,7 @@ class Observer {
 	 *
 	 * @return a new {@link Observer}.
 	 */
-	public static Observer create() {
+	static Observer create() {
 		return new Observer();
 	}
 
@@ -53,7 +54,7 @@ class Observer {
 	 * @return the stateful {@link Observer}.
 	 * @param <C> context type.
 	 */
-	public static <C> Observer fromContext(@Nullable C context, Consumer<? super ContextualObserver<C>> consumer) {
+	static <C> Observer fromContext(@Nullable C context, Consumer<? super ContextualObserver<C>> consumer) {
 
 		Observer contributor = create();
 
@@ -68,7 +69,7 @@ class Observer {
 	 * @param keyValue
 	 * @return
 	 */
-	public Observer contribute(MongoKeyName.MongoKeyValue keyValue) {
+	Observer contribute(MongoKeyName.MongoKeyValue keyValue) {
 
 		keyValues.add(keyValue);
 
@@ -83,7 +84,7 @@ class Observer {
 	 * @return the nested contextual {@link ContextualObserver} that can contribute key-value tuples.
 	 * @param <C>
 	 */
-	public <C> ContextualObserver<C> contextual(@Nullable C context) {
+	<C> ContextualObserver<C> contextual(@Nullable C context) {
 
 		if (context == null) {
 			return new EmptyContextualObserver<>(keyValues);
@@ -92,15 +93,11 @@ class Observer {
 		return new DefaultContextualObserver<>(context, keyValues);
 	}
 
-	public <T> ContextualObserver<T> empty(Class<T> targetType) {
+	KeyValues toKeyValues() {
-		return new EmptyContextualObserver<>(this.keyValues);
-	}
-
-	public KeyValues toKeyValues() {
 		return KeyValues.of(keyValues);
 	}
 
-	public KeyName[] toKeyNames() {
+	KeyName[] toKeyNames() {
 
 		KeyName[] keyNames = new KeyName[keyValues.size()];
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/observability/ImperativeIntegrationTests.java

@@ -81,13 +81,17 @@ public class ImperativeIntegrationTests extends SampleTestRunner {
 
 			for (FinishedSpan span : tracer.getFinishedSpans()) {
 
-				assertThat(span.getTags()).containsEntry("db.system", "mongodb").containsEntry("net.transport", "IP.TCP");
+				assertThat(span.getTags()) //
+					.containsEntry("db.system", "mongodb") //
+					.containsEntry("net.transport", "IP.TCP") //
+					.doesNotContainKey("db.connection_string") //
+					.doesNotContainKey("db.user");
 
 				if (MongoClientVersion.isVersion5orNewer()) {
-					assertThat(span.getTags()).containsKeys("db.connection_string", "db.name", "db.operation",
+					assertThat(span.getTags()).containsKeys("db.name", "db.operation",
 							"db.mongodb.collection", "net.peer.name", "net.peer.port");
 				} else {
-					assertThat(span.getTags()).containsKeys("db.connection_string", "db.name", "db.operation",
+					assertThat(span.getTags()).containsKeys("db.name", "db.operation",
 						"db.mongodb.collection", "net.peer.name", "net.peer.port", "net.sock.peer.addr", "net.sock.peer.port");
 				}
 			}

src/main/antora/modules/ROOT/pages/observability/metrics.adoc

@@ -24,12 +24,10 @@ Fully qualified name of the enclosing class `org.springframework.data.mongodb.ob
 [cols="a,a"]
 |===
 |Name | Description
-|`db.connection_string` _(required)_|MongoDB connection string.
 |`db.mongodb.collection` _(required)_|MongoDB collection name.
 |`db.name` _(required)_|MongoDB database name.
 |`db.operation` _(required)_|MongoDB command value.
 |`db.system` _(required)_|MongoDB database system.
-|`db.user` _(required)_|MongoDB user.
 |`net.peer.name` _(required)_|Name of the database host.
 |`net.peer.port` _(required)_|Logical remote port number.
 |`net.sock.peer.addr` _(required)_|Mongo peer address.

src/main/antora/modules/ROOT/pages/observability/spans.adoc

@@ -15,12 +15,10 @@ Fully qualified name of the enclosing class `org.springframework.data.mongodb.ob
 .Tag Keys
 |===
 |Name | Description
-|`db.connection_string` _(required)_|MongoDB connection string.
 |`db.mongodb.collection` _(required)_|MongoDB collection name.
 |`db.name` _(required)_|MongoDB database name.
 |`db.operation` _(required)_|MongoDB command value.
 |`db.system` _(required)_|MongoDB database system.
-|`db.user` _(required)_|MongoDB user.
 |`net.peer.name` _(required)_|Name of the database host.
 |`net.peer.port` _(required)_|Logical remote port number.
 |`net.sock.peer.addr` _(required)_|Mongo peer address.