DATAMONGO-1467 - Add support for MongoDB 3.2 partialFilterExpression for index creation.

We now support partial filter expression on indexes via Index.partial(…). This allows to create partial indexes that only index the documents in a collection that meet a specified filter expression. 

new Index().named("idx").on("k3y", ASC).partial(filter(where("age").gte(10)))

The filter expression can be set via a plain DBObject or a CriteriaDefinition and is mapped against the associated domain type.

Original pull request: #431.

Author: christophstrobl

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2015 the original author or authors.
+ * Copyright 2011-2016 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.
@@ -15,17 +15,15 @@
  */
 package org.springframework.data.mongodb.core;
 
-import static org.springframework.data.domain.Sort.Direction.*;
-
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
 import org.springframework.dao.DataAccessException;
+import org.springframework.data.mongodb.core.convert.QueryMapper;
 import org.springframework.data.mongodb.core.index.IndexDefinition;
-import org.springframework.data.mongodb.core.index.IndexField;
 import org.springframework.data.mongodb.core.index.IndexInfo;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.util.Assert;
 
 import com.mongodb.DBCollection;
@@ -42,12 +40,11 @@
  */
 public class DefaultIndexOperations implements IndexOperations {
 
-	private static final Double ONE = Double.valueOf(1);
-	private static final Double MINUS_ONE = Double.valueOf(-1);
-	private static final Collection<String> TWO_D_IDENTIFIERS = Arrays.asList("2d", "2dsphere");
-
+	public static final String PARTIAL_FILTER_EXPRESSION_KEY = "partialFilterExpression";
 	private final MongoOperations mongoOperations;
 	private final String collectionName;
+	private final QueryMapper mapper;
+	private final Class<?> type;
 
 	/**
 	 * Creates a new {@link DefaultIndexOperations}.
@@ -56,29 +53,72 @@ public class DefaultIndexOperations implements IndexOperations {
 	 * @param collectionName must not be {@literal null}.
 	 */
 	public DefaultIndexOperations(MongoOperations mongoOperations, String collectionName) {
+		this(mongoOperations, collectionName, null);
+	}
+
+	/**
+	 * Creates a new {@link DefaultIndexOperations}.
+	 *
+	 * @param mongoOperations must not be {@literal null}.
+	 * @param collectionName must not be {@literal null}.
+	 * @param type Type used for mapping potential partial index filter expression. Can be {@literal null}.
+	 * @since 1.10
+	 */
+	public DefaultIndexOperations(MongoOperations mongoOperations, String collectionName, Class<?> type) {
 
 		Assert.notNull(mongoOperations, "MongoOperations must not be null!");
 		Assert.notNull(collectionName, "Collection name can not be null!");
 
 		this.mongoOperations = mongoOperations;
 		this.collectionName = collectionName;
+		this.mapper = new QueryMapper(mongoOperations.getConverter());
+		this.type = type;
 	}
 
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.IndexOperations#ensureIndex(org.springframework.data.mongodb.core.index.IndexDefinition)
 	 */
 	public void ensureIndex(final IndexDefinition indexDefinition) {
+
 		mongoOperations.execute(collectionName, new CollectionCallback<Object>() {
 			public Object doInCollection(DBCollection collection) throws MongoException, DataAccessException {
 				DBObject indexOptions = indexDefinition.getIndexOptions();
+
+				if (indexOptions != null && indexOptions.containsField(PARTIAL_FILTER_EXPRESSION_KEY)) {
+
+					Assert.isInstanceOf(DBObject.class, indexOptions.get(PARTIAL_FILTER_EXPRESSION_KEY));
+
+					indexOptions.put(PARTIAL_FILTER_EXPRESSION_KEY,
+							mapper.getMappedObject((DBObject) indexOptions.get(PARTIAL_FILTER_EXPRESSION_KEY),
+									lookupPersistentEntity(type, collectionName)));
+				}
+
 				if (indexOptions != null) {
 					collection.createIndex(indexDefinition.getIndexKeys(), indexOptions);
 				} else {
 					collection.createIndex(indexDefinition.getIndexKeys());
 				}
 				return null;
 			}
+
+			private MongoPersistentEntity<?> lookupPersistentEntity(Class<?> entityType, String collection) {
+
+				if (entityType != null) {
+					return mongoOperations.getConverter().getMappingContext().getPersistentEntity(entityType);
+				}
+
+				Collection<? extends MongoPersistentEntity<?>> entities = mongoOperations.getConverter().getMappingContext()
+						.getPersistentEntities();
+
+				for (MongoPersistentEntity<?> entity : entities) {
+					if (entity.getCollection().equals(collection)) {
+						return entity;
+					}
+				}
+
+				return null;
+			}
 		});
 	}
 
@@ -136,44 +176,7 @@ private List<IndexInfo> getIndexData(List<DBObject> dbObjectList) {
 				List<IndexInfo> indexInfoList = new ArrayList<IndexInfo>();
 
 				for (DBObject ix : dbObjectList) {
-
-					DBObject keyDbObject = (DBObject) ix.get("key");
-					int numberOfElements = keyDbObject.keySet().size();
-
-					List<IndexField> indexFields = new ArrayList<IndexField>(numberOfElements);
-
-					for (String key : keyDbObject.keySet()) {
-
-						Object value = keyDbObject.get(key);
-
-						if (TWO_D_IDENTIFIERS.contains(value)) {
-							indexFields.add(IndexField.geo(key));
-						} else if ("text".equals(value)) {
-
-							DBObject weights = (DBObject) ix.get("weights");
-							for (String fieldName : weights.keySet()) {
-								indexFields.add(IndexField.text(fieldName, Float.valueOf(weights.get(fieldName).toString())));
-							}
-
-						} else {
-
-							Double keyValue = new Double(value.toString());
-
-							if (ONE.equals(keyValue)) {
-								indexFields.add(IndexField.create(key, ASC));
-							} else if (MINUS_ONE.equals(keyValue)) {
-								indexFields.add(IndexField.create(key, DESC));
-							}
-						}
-					}
-
-					String name = ix.get("name").toString();
-
-					boolean unique = ix.containsField("unique") ? (Boolean) ix.get("unique") : false;
-					boolean dropDuplicates = ix.containsField("dropDups") ? (Boolean) ix.get("dropDups") : false;
-					boolean sparse = ix.containsField("sparse") ? (Boolean) ix.get("sparse") : false;
-					String language = ix.containsField("default_language") ? (String) ix.get("default_language") : "";
-					indexInfoList.add(new IndexInfo(indexFields, name, unique, dropDuplicates, sparse, language));
+					indexInfoList.add(IndexInfo.indexInfoOf(ix));
 				}
 
 				return indexInfoList;

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

@@ -557,7 +557,7 @@ public IndexOperations indexOps(String collectionName) {
 	}
 
 	public IndexOperations indexOps(Class<?> entityClass) {
-		return new DefaultIndexOperations(this, determineCollectionName(entityClass));
+		return new DefaultIndexOperations(this, determineCollectionName(entityClass), entityClass);
 	}
 
 	public BulkOperations bulkOps(BulkMode bulkMode, String collectionName) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2014 the original author or authors.
+ * Copyright 2010-2016 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.
@@ -39,6 +39,7 @@ public class GeospatialIndex implements IndexDefinition {
 	private GeoSpatialIndexType type = GeoSpatialIndexType.GEO_2D;
 	private Double bucketSize = 1.0;
 	private String additionalField;
+	private IndexFilter filter;
 
 	/**
 	 * Creates a new {@link GeospatialIndex} for the given field.
@@ -119,6 +120,22 @@ public GeospatialIndex withAdditionalField(String fieldName) {
 		return this;
 	}
 
+
+	/**
+	 * Only index the documents in a collection that meet a specified {@link IndexFilter filter expression}.
+	 *
+	 * @param filter can be {@literal null}.
+	 * @return
+	 * @see <a href=
+	 *      "https://docs.mongodb.com/manual/core/index-partial/">https://docs.mongodb.com/manual/core/index-partial/</a>
+	 * @since 1.10
+	 */
+	public GeospatialIndex partial(IndexFilter filter) {
+
+		this.filter = filter;
+		return this;
+	}
+
 	public DBObject getIndexKeys() {
 
 		DBObject dbo = new BasicDBObject();
@@ -186,6 +203,10 @@ public DBObject getIndexOptions() {
 				break;
 		}
 
+		if (filter != null) {
+			dbo.put("partialFilterExpression", filter.getFilterObject());
+		}
+
 		return dbo;
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 the original author or authors.
+ * Copyright 2010-2016 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.
@@ -63,6 +63,8 @@ public enum Duplicates {
 
 	private long expire = -1;
 
+	private IndexFilter filter;
+
 	public Index() {}
 
 	public Index(String key, Direction direction) {
@@ -176,6 +178,21 @@ public Index unique(Duplicates duplicates) {
 		return unique();
 	}
 
+	/**
+	 * Only index the documents in a collection that meet a specified {@link IndexFilter filter expression}.
+	 *
+	 * @param filter can be {@literal null}.
+	 * @return
+	 * @see <a href=
+	 *      "https://docs.mongodb.com/manual/core/index-partial/">https://docs.mongodb.com/manual/core/index-partial/</a>
+	 * @since 1.10
+	 */
+	public Index partial(IndexFilter filter) {
+
+		this.filter = filter;
+		return this;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mongodb.core.index.IndexDefinition#getIndexKeys()
@@ -213,6 +230,9 @@ public DBObject getIndexOptions() {
 			dbo.put("expireAfterSeconds", expire);
 		}
 
+		if (filter != null) {
+			dbo.put("partialFilterExpression", filter.getFilterObject());
+		}
 		return dbo;
 	}
 

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

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2016. 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
+ *
+ *      http://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.index;
+
+import com.mongodb.DBObject;
+
+/**
+ * Use {@link IndexFilter} to create the partial filter expression used when creating
+ * <a href="https://docs.mongodb.com/manual/core/index-partial/">Partial Indexes</a>.
+ *
+ * @author Christoph Strobl
+ * @since 1.10
+ */
+public interface IndexFilter {
+
+	/**
+	 * Get the raw (unmapped) filter expression.
+	 *
+	 * @return
+	 */
+	DBObject getFilterObject();
+
+}