/*
* Copyright 2015 MongoDB, Inc.
*
* 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 com.mongodb.client.model;
import org.bson.BsonDocument;
import org.bson.BsonInt32;
import org.bson.BsonString;
import org.bson.BsonValue;
import org.bson.codecs.configuration.CodecRegistry;
import org.bson.conversions.Bson;
import java.util.List;
import static com.mongodb.assertions.Assertions.notNull;
import static java.util.Arrays.asList;
/**
* A factory for defining index keys. A convenient way to use this class is to statically import all of its methods, which allows usage
* like:
* <blockquote><pre>
* collection.createIndex(compoundIndex(ascending("x"), descending("y")));
* </pre></blockquote>
* @since 3.1
*/
public final class Indexes {
private Indexes() {
}
/**
* Create an index key for an ascending index on the given fields.
*
* @param fieldNames the field names, which must contain at least one
* @return the index specification
* @mongodb.driver.manual core/indexes indexes
*/
public static Bson ascending(final String... fieldNames) {
return ascending(asList(fieldNames));
}
/**
* Create an index key for an ascending index on the given fields.
*
* @param fieldNames the field names, which must contain at least one
* @return the index specification
* @mongodb.driver.manual core/indexes indexes
*/
public static Bson ascending(final List<String> fieldNames) {
notNull("fieldNames", fieldNames);
return compoundIndex(fieldNames, new BsonInt32(1));
}
/**
* Create an index key for an ascending index on the given fields.
*
* @param fieldNames the field names, which must contain at least one
* @return the index specification
* @mongodb.driver.manual core/indexes indexes
*/
public static Bson descending(final String... fieldNames) {
return descending(asList(fieldNames));
}
/**
* Create an index key for an ascending index on the given fields.
*
* @param fieldNames the field names, which must contain at least one
* @return the index specification
* @mongodb.driver.manual core/indexes indexes
*/
public static Bson descending(final List<String> fieldNames) {
notNull("fieldNames", fieldNames);
return compoundIndex(fieldNames, new BsonInt32(-1));
}
/**
* Create an index key for an 2dsphere index on the given fields.
*
* @param fieldNames the field names, which must contain at least one
* @return the index specification
* @mongodb.driver.manual core/2dsphere 2dsphere Index
*/
public static Bson geo2dsphere(final String... fieldNames) {
return geo2dsphere(asList(fieldNames));
}
/**
* Create an index key for an ascending index on the given fields.
*
* @param fieldNames the field names, which must contain at least one
* @return the index specification
* @mongodb.driver.manual core/indexes indexes
*/
public static Bson geo2dsphere(final List<String> fieldNames) {
notNull("fieldNames", fieldNames);
return compoundIndex(fieldNames, new BsonString("2dsphere"));
}
/**
* Create an index key for a 2d index on the given field.
*
* <p>
* <strong>Note: </strong>A 2d index is for data stored as points on a two-dimensional plane.
* The 2d index is intended for legacy coordinate pairs used in MongoDB 2.2 and earlier.
* </p>
*
* @param fieldName the field to create a 2d index on
* @return the index specification
* @mongodb.driver.manual core/2d 2d index
*/
public static Bson geo2d(final String fieldName) {
notNull("fieldName", fieldName);
return new BsonDocument(fieldName, new BsonString("2d"));
}
/**
* Create an index key for a geohaystack index on the given field.
*
* <p>
* <strong>Note: </strong>For queries that use spherical geometry, a 2dsphere index is a better option than a haystack index.
* 2dsphere indexes allow field reordering; geoHaystack indexes require the first field to be the location field. Also, geoHaystack
* indexes are only usable via commands and so always return all results at once..
* </p>
*
* @param fieldName the field to create a geoHaystack index on
* @param additional the additional field that forms the geoHaystack index key
* @return the index specification
* @mongodb.driver.manual core/geohaystack geoHaystack index
*/
public static Bson geoHaystack(final String fieldName, final Bson additional) {
notNull("fieldName", fieldName);
return compoundIndex(new BsonDocument(fieldName, new BsonString("geoHaystack")), additional);
}
/**
* Create an index key for a text index on the given field.
*
* @param fieldName the field to create a text index on
* @return the index specification
* @mongodb.driver.manual core/text text index
*/
public static Bson text(final String fieldName) {
notNull("fieldName", fieldName);
return new BsonDocument(fieldName, new BsonString("text"));
}
/**
* Create an index key for a hashed index on the given field.
*
* @param fieldName the field to create a hashed index on
* @return the index specification
* @mongodb.driver.manual core/hashed hashed index
*/
public static Bson hashed(final String fieldName) {
notNull("fieldName", fieldName);
return new BsonDocument(fieldName, new BsonString("hashed"));
}
/**
* create a compound index specifications. If any field names are repeated, the last one takes precedence.
*
* @param indexes the index specifications
* @return the compound index specification
* @mongodb.driver.manual core/index-compound compoundIndex
*/
public static Bson compoundIndex(final Bson... indexes) {
return compoundIndex(asList(indexes));
}
/**
* compound multiple index specifications. If any field names are repeated, the last one takes precedence.
*
* @param indexes the index specifications
* @return the compound index specification
* @mongodb.driver.manual core/index-compound compoundIndex
*/
public static Bson compoundIndex(final List<? extends Bson> indexes) {
notNull("indexes", indexes);
return new Bson() {
@Override
public <TDocument> BsonDocument toBsonDocument(final Class<TDocument> documentClass, final CodecRegistry codecRegistry) {
BsonDocument compoundIndex = new BsonDocument();
for (Bson index : indexes) {
BsonDocument indexDocument = index.toBsonDocument(documentClass, codecRegistry);
for (String key : indexDocument.keySet()) {
compoundIndex.append(key, indexDocument.get(key));
}
}
return compoundIndex;
}
};
}
private static Bson compoundIndex(final List<String> fieldNames, final BsonValue value) {
BsonDocument document = new BsonDocument();
for (String fieldName : fieldNames) {
document.append(fieldName, value);
}
return document;
}
}