DATAMONGO-1894 - Introduce cached ExpressionParser.

Original Pull Request: #874

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/AbstractMongoQuery.java

@@ -30,6 +30,7 @@ import org.springframework.data.repository.query.ParameterAccessor;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
 import org.springframework.data.repository.query.RepositoryQuery;
 import org.springframework.data.repository.query.ResultProcessor;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -47,7 +48,7 @@ public abstract class AbstractMongoQuery implements RepositoryQuery {
 	private final MongoQueryMethod method;
 	private final MongoOperations operations;
 	private final ExecutableFind<?> executableFind;
-	private final SpelExpressionParser expressionParser;
+	private final ExpressionParser expressionParser;
 	private final QueryMethodEvaluationContextProvider evaluationContextProvider;
 
 	/**
@@ -58,7 +59,7 @@ public abstract class AbstractMongoQuery implements RepositoryQuery {
 	 * @param expressionParser must not be {@literal null}.
 	 * @param evaluationContextProvider must not be {@literal null}.
 	 */
-	public AbstractMongoQuery(MongoQueryMethod method, MongoOperations operations, SpelExpressionParser expressionParser,
+	public AbstractMongoQuery(MongoQueryMethod method, MongoOperations operations, ExpressionParser expressionParser,
 			QueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		Assert.notNull(operations, "MongoOperations must not be null!");

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/AbstractReactiveMongoQuery.java

@@ -37,6 +37,7 @@ import org.springframework.data.repository.query.ReactiveQueryMethodEvaluationCo
 import org.springframework.data.repository.query.RepositoryQuery;
 import org.springframework.data.repository.query.ResultProcessor;
 import org.springframework.data.util.TypeInformation;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -54,7 +55,7 @@ public abstract class AbstractReactiveMongoQuery implements RepositoryQuery {
 	private final ReactiveMongoOperations operations;
 	private final EntityInstantiators instantiators;
 	private final FindWithProjection<?> findOperationWithProjection;
-	private final SpelExpressionParser expressionParser;
+	private final ExpressionParser expressionParser;
 	private final ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider;
 
 	/**
@@ -67,7 +68,7 @@ public abstract class AbstractReactiveMongoQuery implements RepositoryQuery {
 	 * @param evaluationContextProvider must not be {@literal null}.
 	 */
 	public AbstractReactiveMongoQuery(ReactiveMongoQueryMethod method, ReactiveMongoOperations operations,
-			SpelExpressionParser expressionParser, ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		Assert.notNull(method, "MongoQueryMethod must not be null!");
 		Assert.notNull(operations, "ReactiveMongoOperations must not be null!");

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/AggregationUtils.java

@@ -34,6 +34,7 @@ import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.mongodb.util.json.ParameterBindingContext;
 import org.springframework.data.mongodb.util.json.ParameterBindingDocumentCodec;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
@@ -64,12 +65,12 @@ abstract class AggregationUtils {
 	 * @param accessor must not be {@literal null}.
 	 * @return the {@link Query} having proper {@link Collation}.
 	 * @see AggregationOptions#getCollation()
-	 * @see CollationUtils#computeCollation(String, ConvertingParameterAccessor, MongoParameters, SpelExpressionParser,
+	 * @see CollationUtils#computeCollation(String, ConvertingParameterAccessor, MongoParameters, ExpressionParser,
 	 *      QueryMethodEvaluationContextProvider)
 	 */
 	static AggregationOptions.Builder applyCollation(AggregationOptions.Builder builder,
 			@Nullable String collationExpression, ConvertingParameterAccessor accessor, MongoParameters parameters,
-			SpelExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		Collation collation = CollationUtils.computeCollation(collationExpression, accessor, parameters, expressionParser,
 				evaluationContextProvider);
@@ -119,7 +120,7 @@ abstract class AggregationUtils {
 	 * @return
 	 */
 	static List<AggregationOperation> computePipeline(MongoQueryMethod method, ConvertingParameterAccessor accessor,
-			SpelExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		ParameterBindingContext bindingContext = new ParameterBindingContext((accessor::getBindableValue), expressionParser,
 				() -> evaluationContextProvider.getEvaluationContext(method.getParameters(), accessor.getValues()));

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/CollationUtils.java

@@ -24,6 +24,7 @@ import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.util.json.ParameterBindingContext;
 import org.springframework.data.mongodb.util.json.ParameterBindingDocumentCodec;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.NumberUtils;
@@ -59,7 +60,7 @@ abstract class CollationUtils {
 	 */
 	@Nullable
 	static Collation computeCollation(@Nullable String collationExpression, ConvertingParameterAccessor accessor,
-			MongoParameters parameters, SpelExpressionParser expressionParser,
+			MongoParameters parameters, ExpressionParser expressionParser,
 			QueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		if (accessor.getCollation() != null) {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/DefaultSpELExpressionEvaluator.java

@@ -35,6 +35,15 @@ class DefaultSpELExpressionEvaluator implements SpELExpressionEvaluator {
 		this.context = context;
 	}
 
+	/**
+	 * Return a {@link SpELExpressionEvaluator} that does not support expression evaluation.
+	 *
+	 * @return a {@link SpELExpressionEvaluator} that does not support expression evaluation.
+	 */
+	public static SpELExpressionEvaluator unsupported() {
+		return NoOpExpressionEvaluator.INSTANCE;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.model.SpELExpressionEvaluator#evaluate(java.lang.String)
@@ -44,4 +53,20 @@ class DefaultSpELExpressionEvaluator implements SpELExpressionEvaluator {
 	public <T> T evaluate(String expression) {
 		return (T) parser.parseExpression(expression).getValue(context, Object.class);
 	}
+
+	/**
+	 * {@link SpELExpressionEvaluator} that does not support SpEL evaluation.
+	 *
+	 * @author Mark Paluch
+	 * @since 3.1
+	 */
+	enum NoOpExpressionEvaluator implements SpELExpressionEvaluator {
+
+		INSTANCE;
+
+		@Override
+		public <T> T evaluate(String expression) {
+			throw new UnsupportedOperationException("Expression evaluation not supported");
+		}
+	}
 }

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/NoOpExpressionEvaluator.java

@@ -1,34 +0,0 @@
-/*
- * Copyright 2020 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.data.mongodb.repository.query;
-
-import org.springframework.data.mapping.model.SpELExpressionEvaluator;
-
-/**
- * {@link SpELExpressionEvaluator} that does not support SpEL evaluation.
- *
- * @author Mark Paluch
- * @since 3.1
- */
-enum NoOpExpressionEvaluator implements SpELExpressionEvaluator {
-
-	INSTANCE;
-
-	@Override
-	public <T> T evaluate(String expression) {
-		throw new UnsupportedOperationException("Expression evaluation not supported");
-	}
-}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/PartTreeMongoQuery.java

@@ -32,7 +32,7 @@ import org.springframework.data.repository.query.RepositoryQuery;
 import org.springframework.data.repository.query.ResultProcessor;
 import org.springframework.data.repository.query.ReturnedType;
 import org.springframework.data.repository.query.parser.PartTree;
-import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.util.StringUtils;
 
 /**
@@ -59,7 +59,7 @@ public class PartTreeMongoQuery extends AbstractMongoQuery {
 	 * @param evaluationContextProvider must not be {@literal null}.
 	 */
 	public PartTreeMongoQuery(MongoQueryMethod method, MongoOperations mongoOperations,
-			SpelExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		super(method, mongoOperations, expressionParser, evaluationContextProvider);
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/QueryUtils.java

@@ -21,6 +21,7 @@ import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.data.mongodb.core.query.Collation;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 
@@ -76,7 +77,7 @@ class QueryUtils {
 	 * @since 2.2
 	 */
 	static Query applyCollation(Query query, @Nullable String collationExpression, ConvertingParameterAccessor accessor,
-			MongoParameters parameters, SpelExpressionParser expressionParser,
+			MongoParameters parameters, ExpressionParser expressionParser,
 			QueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		Collation collation = CollationUtils.computeCollation(collationExpression, accessor, parameters, expressionParser,

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/ReactivePartTreeMongoQuery.java

@@ -33,6 +33,7 @@ import org.springframework.data.repository.query.RepositoryQuery;
 import org.springframework.data.repository.query.ResultProcessor;
 import org.springframework.data.repository.query.ReturnedType;
 import org.springframework.data.repository.query.parser.PartTree;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.util.StringUtils;
 
@@ -59,7 +60,7 @@ public class ReactivePartTreeMongoQuery extends AbstractReactiveMongoQuery {
 	 * @param evaluationContextProvider must not be {@literal null}.
 	 */
 	public ReactivePartTreeMongoQuery(ReactiveMongoQueryMethod method, ReactiveMongoOperations mongoOperations,
-			SpelExpressionParser expressionParser, ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		super(method, mongoOperations, expressionParser, evaluationContextProvider);
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/ReactiveStringBasedAggregation.java

@@ -39,6 +39,7 @@ import org.springframework.data.mongodb.util.json.ParameterBindingDocumentCodec;
 import org.springframework.data.repository.query.ReactiveQueryMethodEvaluationContextProvider;
 import org.springframework.data.repository.query.ResultProcessor;
 import org.springframework.data.spel.ExpressionDependencies;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.util.ClassUtils;
 
@@ -54,7 +55,7 @@ public class ReactiveStringBasedAggregation extends AbstractReactiveMongoQuery {
 
 	private static final ParameterBindingDocumentCodec CODEC = new ParameterBindingDocumentCodec();
 
-	private final SpelExpressionParser expressionParser;
+	private final ExpressionParser expressionParser;
 	private final ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider;
 	private final ReactiveMongoOperations reactiveMongoOperations;
 	private final MongoConverter mongoConverter;
@@ -66,7 +67,7 @@ public class ReactiveStringBasedAggregation extends AbstractReactiveMongoQuery {
 	 * @param evaluationContextProvider must not be {@literal null}.
 	 */
 	public ReactiveStringBasedAggregation(ReactiveMongoQueryMethod method,
-			ReactiveMongoOperations reactiveMongoOperations, SpelExpressionParser expressionParser,
+			ReactiveMongoOperations reactiveMongoOperations, ExpressionParser expressionParser,
 			ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		super(method, reactiveMongoOperations, expressionParser, evaluationContextProvider);
@@ -118,11 +119,7 @@ public class ReactiveStringBasedAggregation extends AbstractReactiveMongoQuery {
 				});
 			}
 
-			if (method.isCollectionQuery()) {
+			return method.isCollectionQuery() ? flux : flux.next();
-				return flux;
-			} else {
-				return flux.next();
-			}
 		});
 	}
 
@@ -145,7 +142,7 @@ public class ReactiveStringBasedAggregation extends AbstractReactiveMongoQuery {
 					it -> evaluationContextProvider.getEvaluationContextLater(method.getParameters(), accessor.getValues(), it))
 					.map(evaluationContext -> evaluationContext
 							.map(it -> (SpELExpressionEvaluator) new DefaultSpELExpressionEvaluator(expressionParser, it)))
-					.orElseGet(() -> Mono.just(NoOpExpressionEvaluator.INSTANCE));
+					.orElseGet(() -> Mono.just(DefaultSpELExpressionEvaluator.unsupported()));
 
 			Mono<AggregationOperation> stage = evaluator.map(it -> {
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/ReactiveStringBasedMongoQuery.java

@@ -53,7 +53,7 @@ public class ReactiveStringBasedMongoQuery extends AbstractReactiveMongoQuery {
 	private final String query;
 	private final String fieldSpec;
 
-	private final SpelExpressionParser expressionParser;
+	private final ExpressionParser expressionParser;
 	private final ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider;
 
 	private final boolean isCountQuery;
@@ -70,7 +70,7 @@ public class ReactiveStringBasedMongoQuery extends AbstractReactiveMongoQuery {
 	 * @param evaluationContextProvider must not be {@literal null}.
 	 */
 	public ReactiveStringBasedMongoQuery(ReactiveMongoQueryMethod method, ReactiveMongoOperations mongoOperations,
-			SpelExpressionParser expressionParser, ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
 		this(method.getAnnotatedQuery(), method, mongoOperations, expressionParser, evaluationContextProvider);
 	}
 
@@ -85,7 +85,7 @@ public class ReactiveStringBasedMongoQuery extends AbstractReactiveMongoQuery {
 	 * @param expressionParser must not be {@literal null}.
 	 */
 	public ReactiveStringBasedMongoQuery(String query, ReactiveMongoQueryMethod method,
-			ReactiveMongoOperations mongoOperations, SpelExpressionParser expressionParser,
+			ReactiveMongoOperations mongoOperations, ExpressionParser expressionParser,
 			ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		super(method, mongoOperations, expressionParser, evaluationContextProvider);
@@ -153,7 +153,7 @@ public class ReactiveStringBasedMongoQuery extends AbstractReactiveMongoQuery {
 						accessor.getValues(), it))
 				.map(evaluationContext -> evaluationContext
 						.map(it -> (SpELExpressionEvaluator) new DefaultSpELExpressionEvaluator(expressionParser, it)))
-				.orElseGet(() -> Mono.just(NoOpExpressionEvaluator.INSTANCE));
+				.orElseGet(() -> Mono.just(DefaultSpELExpressionEvaluator.unsupported()));
 
 		return evaluator.map(it -> new ParameterBindingContext(accessor::getBindableValue, it));
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/StringBasedAggregation.java

@@ -32,7 +32,7 @@ import org.springframework.data.mongodb.core.mapping.MongoSimpleTypes;
 import org.springframework.data.mongodb.core.query.Query;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
 import org.springframework.data.repository.query.ResultProcessor;
-import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.util.ClassUtils;
 
 /**
@@ -43,7 +43,7 @@ public class StringBasedAggregation extends AbstractMongoQuery {
 
 	private final MongoOperations mongoOperations;
 	private final MongoConverter mongoConverter;
-	private final SpelExpressionParser expressionParser;
+	private final ExpressionParser expressionParser;
 	private final QueryMethodEvaluationContextProvider evaluationContextProvider;
 
 	/**
@@ -55,7 +55,7 @@ public class StringBasedAggregation extends AbstractMongoQuery {
 	 * @param evaluationContextProvider
 	 */
 	public StringBasedAggregation(MongoQueryMethod method, MongoOperations mongoOperations,
-			SpelExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
 		super(method, mongoOperations, expressionParser, evaluationContextProvider);
 
 		this.mongoOperations = mongoOperations;

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/StringBasedMongoQuery.java

@@ -54,7 +54,7 @@ public class StringBasedMongoQuery extends AbstractMongoQuery {
 	private final String fieldSpec;
 
 	private final ParameterBindingDocumentCodec codec;
-	private final SpelExpressionParser expressionParser;
+	private final ExpressionParser expressionParser;
 	private final QueryMethodEvaluationContextProvider evaluationContextProvider;
 
 	private final boolean isCountQuery;
@@ -71,7 +71,7 @@ public class StringBasedMongoQuery extends AbstractMongoQuery {
 	 * @param evaluationContextProvider must not be {@literal null}.
 	 */
 	public StringBasedMongoQuery(MongoQueryMethod method, MongoOperations mongoOperations,
-			SpelExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
 		this(method.getAnnotatedQuery(), method, mongoOperations, expressionParser, evaluationContextProvider);
 	}
 
@@ -85,7 +85,7 @@ public class StringBasedMongoQuery extends AbstractMongoQuery {
 	 * @param expressionParser must not be {@literal null}.
 	 */
 	public StringBasedMongoQuery(String query, MongoQueryMethod method, MongoOperations mongoOperations,
-			SpelExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
+			ExpressionParser expressionParser, QueryMethodEvaluationContextProvider evaluationContextProvider) {
 
 		super(method, mongoOperations, expressionParser, evaluationContextProvider);
 
@@ -151,7 +151,7 @@ public class StringBasedMongoQuery extends AbstractMongoQuery {
 						accessor.getValues(), it))
 				.map(evaluationContext -> (SpELExpressionEvaluator) new DefaultSpELExpressionEvaluator(expressionParser,
 						evaluationContext))
-				.orElse(NoOpExpressionEvaluator.INSTANCE);
+				.orElse(DefaultSpELExpressionEvaluator.unsupported());
 
 		return new ParameterBindingContext(accessor::getBindableValue, evaluator);
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/CachingExpressionParser.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2020 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.data.mongodb.repository.support;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.ParseException;
+import org.springframework.expression.ParserContext;
+
+/**
+ * Caching variant of {@link ExpressionParser}. This implementation does not support
+ * {@link #parseExpression(String, ParserContext) parsing with ParseContext}.
+ *
+ * @author Mark Paluch
+ * @since 3.1
+ */
+class CachingExpressionParser implements ExpressionParser {
+
+	private final ExpressionParser delegate;
+	private final Map<String, Expression> cache = new ConcurrentHashMap<>();
+
+	public CachingExpressionParser(ExpressionParser delegate) {
+		this.delegate = delegate;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.expression.ExpressionParser#parseExpression(java.lang.String)
+	 */
+	@Override
+	public Expression parseExpression(String expressionString) throws ParseException {
+		return cache.computeIfAbsent(expressionString, delegate::parseExpression);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.expression.ExpressionParser#parseExpression(java.lang.String, org.springframework.expression.ParserContext)
+	 */
+	@Override
+	public Expression parseExpression(String expressionString, ParserContext context) throws ParseException {
+		throw new UnsupportedOperationException("Parsing using ParserContext is not supported");
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/MongoRepositoryFactory.java

@@ -44,6 +44,7 @@ import org.springframework.data.repository.query.QueryLookupStrategy;
 import org.springframework.data.repository.query.QueryLookupStrategy.Key;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
 import org.springframework.data.repository.query.RepositoryQuery;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -162,7 +163,8 @@ public class MongoRepositoryFactory extends RepositoryFactorySupport {
 
 		private final MongoOperations operations;
 		private final QueryMethodEvaluationContextProvider evaluationContextProvider;
-		MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+		private final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+		private final ExpressionParser expressionParser = new CachingExpressionParser(EXPRESSION_PARSER);
 
 		public MongoQueryLookupStrategy(MongoOperations operations,
 				QueryMethodEvaluationContextProvider evaluationContextProvider,
@@ -186,14 +188,14 @@ public class MongoRepositoryFactory extends RepositoryFactorySupport {
 
 			if (namedQueries.hasQuery(namedQueryName)) {
 				String namedQuery = namedQueries.getQuery(namedQueryName);
-				return new StringBasedMongoQuery(namedQuery, queryMethod, operations, EXPRESSION_PARSER,
+				return new StringBasedMongoQuery(namedQuery, queryMethod, operations, expressionParser,
 						evaluationContextProvider);
 			} else if (queryMethod.hasAnnotatedAggregation()) {
-				return new StringBasedAggregation(queryMethod, operations, EXPRESSION_PARSER, evaluationContextProvider);
+				return new StringBasedAggregation(queryMethod, operations, expressionParser, evaluationContextProvider);
 			} else if (queryMethod.hasAnnotatedQuery()) {
-				return new StringBasedMongoQuery(queryMethod, operations, EXPRESSION_PARSER, evaluationContextProvider);
+				return new StringBasedMongoQuery(queryMethod, operations, expressionParser, evaluationContextProvider);
 			} else {
-				return new PartTreeMongoQuery(queryMethod, operations, EXPRESSION_PARSER, evaluationContextProvider);
+				return new PartTreeMongoQuery(queryMethod, operations, expressionParser, evaluationContextProvider);
 			}
 		}
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/support/ReactiveMongoRepositoryFactory.java

@@ -44,6 +44,7 @@ import org.springframework.data.repository.query.QueryLookupStrategy.Key;
 import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
 import org.springframework.data.repository.query.ReactiveQueryMethodEvaluationContextProvider;
 import org.springframework.data.repository.query.RepositoryQuery;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -161,6 +162,7 @@ public class ReactiveMongoRepositoryFactory extends ReactiveRepositoryFactorySup
 		private final ReactiveMongoOperations operations;
 		private final ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider;
 		private final MappingContext<? extends MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+		private final ExpressionParser expressionParser = new CachingExpressionParser(EXPRESSION_PARSER);
 
 		MongoQueryLookupStrategy(ReactiveMongoOperations operations,
 				ReactiveQueryMethodEvaluationContextProvider evaluationContextProvider,
@@ -184,15 +186,15 @@ public class ReactiveMongoRepositoryFactory extends ReactiveRepositoryFactorySup
 
 			if (namedQueries.hasQuery(namedQueryName)) {
 				String namedQuery = namedQueries.getQuery(namedQueryName);
-				return new ReactiveStringBasedMongoQuery(namedQuery, queryMethod, operations, EXPRESSION_PARSER,
+				return new ReactiveStringBasedMongoQuery(namedQuery, queryMethod, operations, expressionParser,
 						evaluationContextProvider);
 			} else if (queryMethod.hasAnnotatedAggregation()) {
-				return new ReactiveStringBasedAggregation(queryMethod, operations, EXPRESSION_PARSER,
+				return new ReactiveStringBasedAggregation(queryMethod, operations, expressionParser,
 						evaluationContextProvider);
 			} else if (queryMethod.hasAnnotatedQuery()) {
-				return new ReactiveStringBasedMongoQuery(queryMethod, operations, EXPRESSION_PARSER, evaluationContextProvider);
+				return new ReactiveStringBasedMongoQuery(queryMethod, operations, expressionParser, evaluationContextProvider);
 			} else {
-				return new ReactivePartTreeMongoQuery(queryMethod, operations, EXPRESSION_PARSER, evaluationContextProvider);
+				return new ReactivePartTreeMongoQuery(queryMethod, operations, expressionParser, evaluationContextProvider);
 			}
 		}
 	}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/util/json/ParameterBindingContext.java

@@ -23,6 +23,7 @@ import org.springframework.data.spel.ExpressionDependencies;
 import org.springframework.data.util.Lazy;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.lang.Nullable;
 
@@ -55,7 +56,7 @@ public class ParameterBindingContext {
 	 * @param evaluationContext a {@link Supplier} for {@link Lazy} context retrieval.
 	 * @since 2.2.3
 	 */
-	public ParameterBindingContext(ValueProvider valueProvider, SpelExpressionParser expressionParser,
+	public ParameterBindingContext(ValueProvider valueProvider, ExpressionParser expressionParser,
 			Supplier<EvaluationContext> evaluationContext) {
 
 		this(valueProvider, new SpELExpressionEvaluator() {
@@ -87,7 +88,7 @@ public class ParameterBindingContext {
 	 * @since 3.1
 	 */
 	public static ParameterBindingContext forExpressions(ValueProvider valueProvider,
-			SpelExpressionParser expressionParser, Function<ExpressionDependencies, EvaluationContext> contextFunction) {
+			ExpressionParser expressionParser, Function<ExpressionDependencies, EvaluationContext> contextFunction) {
 
 		return new ParameterBindingContext(valueProvider, new SpELExpressionEvaluator() {
 			@Override

src/main/asciidoc/new-features.adoc

@@ -5,6 +5,7 @@
 == What's New in Spring Data MongoDB 3.1
 
 * <<mongo.auditing,Reactive auditing>> enabled through `@EnableReactiveMongoAuditing`. `@EnableMongoAuditing` no longer registers `ReactiveAuditingEntityCallback`.
+* Reactive SpEL support in `@Query` and `@Aggregation` query methods.
 
 [[new-features.3.0]]
 == What's New in Spring Data MongoDB 3.0

src/main/asciidoc/reference/mongo-repositories.adoc

@@ -492,13 +492,15 @@ public class SampleEvaluationContextExtension extends EvaluationContextExtension
 }
 ----
 
-NOTE: Bootstrapping `MongoRepositoryFactory` yourself is not application context-aware and requires further configuration
+NOTE: Bootstrapping `MongoRepositoryFactory` yourself is not application context-aware and requires further configuration to pick up Query SPI extensions.
-to pick up Query SPI extensions.
+
+NOTE: Reactive query methods can make use of `org.springframework.data.spel.spi.ReactiveEvaluationContextExtension`.
 
 [[mongodb.repositories.queries.type-safe]]
 === Type-safe Query Methods
 
-MongoDB repository support integrates with the http://www.querydsl.com/[Querydsl] project, which provides a way to perform type-safe queries. To quote from the project description, "Instead of writing queries as inline strings or externalizing them into XML files they are constructed via a fluent API." It provides the following features:
+MongoDB repository support integrates with the http://www.querydsl.com/[Querydsl] project, which provides a way to perform type-safe queries.
+To quote from the project description, "Instead of writing queries as inline strings or externalizing them into XML files they are constructed via a fluent API." It provides the following features:
 
 * Code completion in the IDE (all properties, methods, and operations can be expanded in your favorite Java IDE).
 * Almost no syntactically invalid queries allowed (type-safe on all levels).