Support ReadConcern and ReadPreference via NearQuery.

Implement ReadConcernAware and ReadPreferenceAware for NearQuery and make sure those get applied when working with the template API.

Original Pull Request: #4288

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java

@@ -948,10 +948,13 @@ public <T> GeoResults<T> geoNear(NearQuery near, Class<?> domainType, String col
 		String distanceField = operations.nearQueryDistanceFieldName(domainType);
 
 		Builder optionsBuilder = AggregationOptions.builder().collation(near.getCollation());
-		Query query = near.getQuery();
 
-		if (query != null && query.hasReadPreference()) {
-			optionsBuilder.readPreference(query.getReadPreference());
+		if (near.hasReadPreference()) {
+			optionsBuilder.readPreference(near.getReadPreference());
+		}
+
+		if(near.hasReadConcern()) {
+			optionsBuilder.readConcern(near.getReadConcern());
 		}
 
 		Aggregation $geoNear = TypedAggregation.newAggregation(domainType, Aggregation.geoNear(near, distanceField))

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoTemplate.java

@@ -81,6 +81,7 @@
 import org.springframework.data.mongodb.core.aggregation.Aggregation;
 import org.springframework.data.mongodb.core.aggregation.AggregationOperationContext;
 import org.springframework.data.mongodb.core.aggregation.AggregationOptions;
+import org.springframework.data.mongodb.core.aggregation.AggregationOptions.Builder;
 import org.springframework.data.mongodb.core.aggregation.AggregationPipeline;
 import org.springframework.data.mongodb.core.aggregation.PrefixingDelegatingAggregationOperationContext;
 import org.springframework.data.mongodb.core.aggregation.RelaxedTypeBasedAggregationOperationContext;
@@ -998,8 +999,19 @@ protected <T> Flux<GeoResult<T>> geoNear(NearQuery near, Class<?> entityClass, S
 		GeoNearResultDocumentCallback<T> callback = new GeoNearResultDocumentCallback<>(distanceField,
 				new ProjectingReadCallback<>(mongoConverter, projection, collection), near.getMetric());
 
+		Builder optionsBuilder = AggregationOptions.builder();
+		if (near.hasReadPreference()) {
+			optionsBuilder.readPreference(near.getReadPreference());
+		}
+
+		if(near.hasReadConcern()) {
+			optionsBuilder.readConcern(near.getReadConcern());
+		}
+
+		optionsBuilder.collation(near.getCollation());
+
 		Aggregation $geoNear = TypedAggregation.newAggregation(entityClass, Aggregation.geoNear(near, distanceField))
-				.withOptions(AggregationOptions.builder().collation(near.getCollation()).build());
+				.withOptions(optionsBuilder.build());
 
 		return aggregate($geoNear, collection, Document.class) //
 				.concatMap(callback::doWith);

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/NearQuery.java

@@ -24,11 +24,16 @@
 import org.springframework.data.geo.Metric;
 import org.springframework.data.geo.Metrics;
 import org.springframework.data.geo.Point;
+import org.springframework.data.mongodb.core.ReadConcernAware;
+import org.springframework.data.mongodb.core.ReadPreferenceAware;
 import org.springframework.data.mongodb.core.geo.GeoJsonPoint;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
+import com.mongodb.ReadConcern;
+import com.mongodb.ReadPreference;
+
 /**
  * Builder class to build near-queries. <br />
  * MongoDB {@code $geoNear} operator allows usage of a {@literal GeoJSON Point} or legacy coordinate pair. Though
@@ -171,7 +176,7 @@
  * @author Christoph Strobl
  * @author Mark Paluch
  */
-public final class NearQuery {
+public final class NearQuery implements ReadConcernAware, ReadPreferenceAware {
 
 	private final Point point;
 	private @Nullable Query query;
@@ -181,6 +186,8 @@ public final class NearQuery {
 	private boolean spherical;
 	private @Nullable Long limit;
 	private @Nullable Long skip;
+	private @Nullable ReadConcern readConcern;
+	private @Nullable ReadPreference readPreference;
 
 	/**
 	 * Creates a new {@link NearQuery}.
@@ -536,11 +543,6 @@ public NearQuery query(Query query) {
 		return this;
 	}
 
-	@Nullable
-	public Query getQuery() {
-		return query;
-	}
-
 	/**
 	 * @return the number of elements to skip.
 	 */
@@ -560,6 +562,74 @@ public Collation getCollation() {
 		return query != null ? query.getCollation().orElse(null) : null;
 	}
 
+	/**
+	 * Configures the query to use the given {@link ReadConcern} unless the underlying {@link #query(Query)}
+	 * {@link Query#hasReadConcern() specifies} another one.
+	 *
+	 * @param readConcern must not be {@literal null}.
+	 * @return this.
+	 * @since 4.1
+	 */
+	public NearQuery withReadConcern(ReadConcern readConcern) {
+
+		Assert.notNull(readConcern, "ReadConcern must not be null");
+		this.readConcern = readConcern;
+		return this;
+	}
+
+	/**
+	 * Configures the query to use the given {@link ReadPreference} unless the underlying {@link #query(Query)}
+	 * {@link Query#hasReadPreference() specifies} another one.
+	 *
+	 * @param readPreference must not be {@literal null}.
+	 * @return this.
+	 * @since 4.1
+	 */
+	public NearQuery withReadPreference(ReadPreference readPreference) {
+
+		Assert.notNull(readPreference, "ReadPreference must not be null");
+		this.readPreference = readPreference;
+		return this;
+	}
+
+	/**
+	 * Get the {@link ReadConcern} to use. Will return the underlying {@link #query(Query) queries}
+	 * {@link Query#getReadConcern() ReadConcern} if present or the one defined on the {@link NearQuery#readConcern}
+	 * itself.
+	 * 
+	 * @return can be {@literal null} if none set.
+	 * @since 4.1
+	 * @see ReadConcernAware
+	 */
+	@Nullable
+	@Override
+	public ReadConcern getReadConcern() {
+
+		if (query != null && query.hasReadConcern()) {
+			return query.getReadConcern();
+		}
+		return readConcern;
+	}
+
+	/**
+	 * Get the {@link ReadPreference} to use. Will return the underlying {@link #query(Query) queries}
+	 * {@link Query#getReadPreference() ReadPreference} if present or the one defined on the
+	 * {@link NearQuery#readPreference} itself.
+	 *
+	 * @return can be {@literal null} if none set.
+	 * @since 4.1
+	 * @see ReadPreferenceAware
+	 */
+	@Nullable
+	@Override
+	public ReadPreference getReadPreference() {
+
+		if (query != null && query.hasReadPreference()) {
+			return query.getReadPreference();
+		}
+		return readPreference;
+	}
+
 	/**
 	 * Returns the {@link Document} built by the {@link NearQuery}.
 	 *

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/MongoTemplateUnitTests.java

@@ -583,15 +583,24 @@ void geoNearShouldHonorReadPreferenceWhenSet() {
 	void geoNearShouldHonorReadPreferenceFromQuery() {
 
 		NearQuery query = NearQuery.near(new Point(1, 1));
+		query.withReadPreference(ReadPreference.secondary());
 
-		Query inner = new Query();
-		inner.withReadPreference(ReadPreference.secondary());
-		query.query(inner);
 		template.geoNear(query, Wrapper.class);
 
 		verify(collection).withReadPreference(eq(ReadPreference.secondary()));
 	}
 
+	@Test // GH-4277
+	void geoNearShouldHonorReadConcernFromQuery() {
+
+		NearQuery query = NearQuery.near(new Point(1, 1));
+		query.withReadConcern(ReadConcern.SNAPSHOT);
+
+		template.geoNear(query, Wrapper.class);
+
+		verify(collection).withReadConcern(eq(ReadConcern.SNAPSHOT));
+	}
+
 	@Test // DATAMONGO-1166, DATAMONGO-2264
 	void geoNearShouldIgnoreReadPreferenceWhenNotSet() {
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/ReactiveMongoTemplateUnitTests.java

@@ -59,6 +59,7 @@
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.data.annotation.Id;
+import org.springframework.data.geo.Point;
 import org.springframework.data.mapping.MappingException;
 import org.springframework.data.mapping.callback.ReactiveEntityCallbacks;
 import org.springframework.data.mapping.context.MappingContext;
@@ -384,6 +385,28 @@ void geoNearShouldUseCollationWhenPresent() {
 		verify(aggregatePublisher).collation(eq(com.mongodb.client.model.Collation.builder().locale("fr").build()));
 	}
 
+	@Test // GH-4277
+	void geoNearShouldHonorReadPreferenceFromQuery() {
+
+		NearQuery query = NearQuery.near(new Point(1, 1));
+		query.withReadPreference(ReadPreference.secondary());
+
+		template.geoNear(query, Wrapper.class).subscribe();
+
+		verify(collection).withReadPreference(eq(ReadPreference.secondary()));
+	}
+
+	@Test // GH-4277
+	void geoNearShouldHonorReadConcernFromQuery() {
+
+		NearQuery query = NearQuery.near(new Point(1, 1));
+		query.withReadConcern(ReadConcern.SNAPSHOT);
+
+		template.geoNear(query, Wrapper.class).subscribe();
+
+		verify(collection).withReadConcern(eq(ReadConcern.SNAPSHOT));
+	}
+
 	@Test // DATAMONGO-1719
 	void appliesFieldsWhenInterfaceProjectionIsClosedAndQueryDoesNotDefineFields() {
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/query/NearQueryUnitTests.java

@@ -29,6 +29,10 @@
 import org.springframework.data.geo.Point;
 import org.springframework.data.mongodb.core.DocumentTestUtils;
 import org.springframework.data.mongodb.core.geo.GeoJsonPoint;
+import org.springframework.test.util.ReflectionTestUtils;
+
+import com.mongodb.ReadConcern;
+import com.mongodb.ReadPreference;
 
 /**
  * Unit tests for {@link NearQuery}.
@@ -229,4 +233,58 @@ public void shouldUseMilesForDistanceWhenMaxDistanceInKilometers() {
 
 		assertThat(query.toDocument()).containsEntry("maxDistance", 1000D).containsEntry("distanceMultiplier", 0.00062137D);
 	}
+
+	@Test // GH-4277
+	void fetchesReadPreferenceFromUnderlyingQueryObject() {
+
+		NearQuery nearQuery = NearQuery.near(new Point(0, 0))
+				.query(new Query().withReadPreference(ReadPreference.nearest()));
+
+		assertThat(nearQuery.getReadPreference()).isEqualTo(ReadPreference.nearest());
+	}
+
+	@Test // GH-4277
+	void fetchesReadConcernFromUnderlyingQueryObject() {
+
+		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).query(new Query().withReadConcern(ReadConcern.SNAPSHOT));
+
+		assertThat(nearQuery.getReadConcern()).isEqualTo(ReadConcern.SNAPSHOT);
+	}
+
+	@Test // GH-4277
+	void usesReadPreferenceFromNearQueryIfUnderlyingQueryDoesNotDefineAny() {
+
+		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadPreference(ReadPreference.nearest())
+				.query(new Query());
+
+		assertThat(((Query) ReflectionTestUtils.getField(nearQuery, "query")).getReadPreference()).isNull();
+		assertThat(nearQuery.getReadPreference()).isEqualTo(ReadPreference.nearest());
+	}
+
+	@Test // GH-4277
+	void usesReadConcernFromNearQueryIfUnderlyingQueryDoesNotDefineAny() {
+
+		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadConcern(ReadConcern.SNAPSHOT).query(new Query());
+
+		assertThat(((Query) ReflectionTestUtils.getField(nearQuery, "query")).getReadConcern()).isNull();
+		assertThat(nearQuery.getReadConcern()).isEqualTo(ReadConcern.SNAPSHOT);
+	}
+
+	@Test // GH-4277
+	void readPreferenceFromUnderlyingQueryOverridesNearQueryOne() {
+
+		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadPreference(ReadPreference.nearest())
+				.query(new Query().withReadPreference(ReadPreference.primary()));
+
+		assertThat(nearQuery.getReadPreference()).isEqualTo(ReadPreference.primary());
+	}
+
+	@Test // GH-4277
+	void readConcernFromUnderlyingQueryOverridesNearQueryOne() {
+
+		NearQuery nearQuery = NearQuery.near(new Point(0, 0)).withReadConcern(ReadConcern.SNAPSHOT)
+				.query(new Query().withReadConcern(ReadConcern.MAJORITY));
+
+		assertThat(nearQuery.getReadConcern()).isEqualTo(ReadConcern.MAJORITY);
+	}
 }