From 30da62181f92ee1e6983eccc4d017941e97ebbb8 Mon Sep 17 00:00:00 2001 From: Christoph Strobl Date: Thu, 22 Jul 2021 13:39:05 +0200 Subject: [PATCH] Add support for `$rank` and `$denseRank` aggregation operators. Closes: #3715 Original pull request: #3741. --- .../core/aggregation/DocumentOperators.java | 76 +++++++++++++++++++ .../SpelExpressionTransformer.java | 5 +- .../core/spel/MethodReferenceNode.java | 16 +++- .../DocumentOperatorsUnitTests.java | 39 ++++++++++ .../SpelExpressionTransformerUnitTests.java | 10 +++ 5 files changed, 144 insertions(+), 2 deletions(-) create mode 100644 spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/DocumentOperators.java create mode 100644 spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/DocumentOperatorsUnitTests.java diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/DocumentOperators.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/DocumentOperators.java new file mode 100644 index 000000000..8ba7acc5b --- /dev/null +++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/DocumentOperators.java @@ -0,0 +1,76 @@ +/* + * Copyright 2021 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.core.aggregation; + +import org.bson.Document; + +/** + * @author Christoph Strobl + * @since 3.3 + */ +public class DocumentOperators { + + /** + * Obtain the document position (including gaps) relative to others (rank). + * + * @return new instance of {@link Rank}. + * @since 3.3 + */ + public static Rank rank() { + return new Rank(); + } + + /** + * Obtain the document position (without gaps) relative to others (rank). + * + * @return new instance of {@link DenseRank}. + * @since 3.3 + */ + public static DenseRank denseRank() { + return new DenseRank(); + } + + /** + * {@link Rank} resolves the current document position (the rank) relative to other documents. If multiple documents + * occupy the same rank, {@literal $rank} places the document with the subsequent value at a rank with a gap. + * + * @author Christoph Strobl + * @since 3.3 + */ + public static class Rank implements AggregationExpression { + + @Override + public Document toDocument(AggregationOperationContext context) { + return new Document("$rank", new Document()); + } + } + + /** + * {@link DenseRank} resolves the current document position (the rank) relative to other documents. If multiple + * documents occupy the same rank, {@literal $denseRank} places the document with the subsequent value at the next rank without + * any gaps. + * + * @author Christoph Strobl + * @since 3.3 + */ + public static class DenseRank implements AggregationExpression { + + @Override + public Document toDocument(AggregationOperationContext context) { + return new Document("$denseRank", new Document()); + } + } +} diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformer.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformer.java index 33b5c72c7..e00740945 100644 --- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformer.java +++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformer.java @@ -500,7 +500,10 @@ class SpelExpressionTransformer implements AggregationExpressionTransformer { dbo.put(methodReference.getArgumentMap()[i++], transform(child, context)); } args = dbo; - } else { + } else if (ObjectUtils.nullSafeEquals(methodReference.getArgumentType(), ArgumentType.EMPTY_DOCUMENT)) { + args = new Document(); + } + else { List argList = new ArrayList(); diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/spel/MethodReferenceNode.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/spel/MethodReferenceNode.java index c85892644..763ae830e 100644 --- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/spel/MethodReferenceNode.java +++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/spel/MethodReferenceNode.java @@ -68,6 +68,10 @@ public class MethodReferenceNode extends ExpressionNode { map.put("lte", arrayArgRef().forOperator("$lte")); map.put("ne", arrayArgRef().forOperator("$ne")); + // DOCUMENT OPERATORS + map.put("rank", emptyRef().forOperator("$rank")); + map.put("denseRank", emptyRef().forOperator("$denseRank")); + // ARITHMETIC OPERATORS map.put("abs", singleArgRef().forOperator("$abs")); map.put("add", arrayArgRef().forOperator("$add")); @@ -307,6 +311,16 @@ public class MethodReferenceNode extends ExpressionNode { return new AggregationMethodReference(null, ArgumentType.MAP, null); } + /** + * Create a new {@link AggregationMethodReference} for a {@link ArgumentType#EMPTY_DOCUMENT} argument. + * + * @return never {@literal null}. + * @since 3.3 + */ + static AggregationMethodReference emptyRef() { + return new AggregationMethodReference(null, ArgumentType.EMPTY_DOCUMENT, null); + } + /** * Create a new {@link AggregationMethodReference} for a given {@literal aggregationExpressionOperator} reusing * previously set arguments. @@ -342,7 +356,7 @@ public class MethodReferenceNode extends ExpressionNode { * @since 1.10 */ public enum ArgumentType { - SINGLE, ARRAY, MAP + SINGLE, ARRAY, MAP, EMPTY_DOCUMENT } } diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/DocumentOperatorsUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/DocumentOperatorsUnitTests.java new file mode 100644 index 000000000..27ac1becc --- /dev/null +++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/DocumentOperatorsUnitTests.java @@ -0,0 +1,39 @@ +/* + * Copyright 2021 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.core.aggregation; + +import static org.assertj.core.api.Assertions.*; +import static org.springframework.data.mongodb.core.aggregation.DocumentOperators.*; + +import org.bson.Document; +import org.junit.jupiter.api.Test; + +/** + * @author Christoph Strobl + */ +class DocumentOperatorsUnitTests { + + @Test // GH-3715 + void rendersRank() { + assertThat(rank().toDocument(Aggregation.DEFAULT_CONTEXT)).isEqualTo(new Document("$rank", new Document())); + } + + @Test // GH-3715 + void rendersDenseRank() { + assertThat(denseRank().toDocument(Aggregation.DEFAULT_CONTEXT)) + .isEqualTo(new Document("$denseRank", new Document())); + } +} diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformerUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformerUnitTests.java index c4b945ab9..06659820d 100644 --- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformerUnitTests.java +++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/SpelExpressionTransformerUnitTests.java @@ -956,6 +956,16 @@ public class SpelExpressionTransformerUnitTests { assertThat(transform("covarianceSamp(field1, field2)")).isEqualTo(Document.parse("{ \"$covarianceSamp\" : [\"$field1\", \"$field2\"]}")); } + @Test // GH-3715 + void shouldRenderRank() { + assertThat(transform("rank()")).isEqualTo(Document.parse("{ $rank : {} }")); + } + + @Test // GH-3715 + void shouldRenderDenseRank() { + assertThat(transform("denseRank()")).isEqualTo(Document.parse("{ $denseRank : {} }")); + } + private Object transform(String expression, Object... params) { Object result = transformer.transform(expression, Aggregation.DEFAULT_CONTEXT, params); return result == null ? null : (!(result instanceof org.bson.Document) ? result.toString() : result);