DBCollection

java.lang.Object
- com.mongodb.DBCollection

@ThreadSafe
public class DBCollection
extends Object

Implementation of a database collection. A typical invocation sequence is thus:

 
 MongoClient mongoClient = new MongoClient(new ServerAddress("localhost", 27017));
 DB db = mongoClient.getDB("mydb");
 DBCollection collection = db.getCollection("test");

To get a collection to use, just specify the name of the collection to the getCollection(String collectionName) method:

 
 DBCollection coll = db.getCollection("testCollection");

Once you have the collection object, you can insert documents into the collection:

 
 BasicDBObject doc = new BasicDBObject("name", "MongoDB").append("type", "database")
                                                         .append("count", 1)
                                                         .append("info", new BasicDBObject("x", 203).append("y", 102));
 coll.insert(doc);

To show that the document we inserted in the previous step is there, we can do a simple findOne() operation to get the first document in the collection:

 
 DBObject myDoc = coll.findOne();
 System.out.println(myDoc);

See Mongo.getDB(String) for further information about the effective deprecation of this class.

MongoDB documentation: Collection

Field Summary

Fields
Modifier and Type Field Description

static String ID_FIELD_NAME

Fields
Modifier and Type	Field	Description
`static String`	`ID_FIELD_NAME`

Constructor Summary

Constructors
Modifier Constructor Description

protected DBCollection(DB database, String name)
Initializes a new collection.

Constructors
Modifier	Constructor	Description
`protected`	`DBCollection(DB database, String name)`	Initializes a new collection.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`addOption(int option)`	Adds the given flag to the default query options.
`AggregationOutput`	`aggregate(DBObject firstOp, DBObject... additionalOps)`	Deprecated. Use `aggregate(List, AggregationOptions)` instead
`AggregationOutput`	`aggregate(List<? extends DBObject> pipeline)`	Deprecated. Use `aggregate(List, AggregationOptions)` instead
`Cursor`	`aggregate(List<? extends DBObject> pipeline, AggregationOptions options)`	Method implements aggregation framework.
`Cursor`	`aggregate(List<? extends DBObject> pipeline, AggregationOptions options, ReadPreference readPreference)`	Method implements aggregation framework.
`AggregationOutput`	`aggregate(List<? extends DBObject> pipeline, ReadPreference readPreference)`	Deprecated. Use `aggregate(List, AggregationOptions, ReadPreference)` )} instead
`long`	`count()`	Same as `getCount()`
`long`	`count(DBObject query)`	Same as `getCount(DBObject)`
`long`	`count(DBObject query, DBCollectionCountOptions options)`	Get the count of documents in collection that would match a criteria.
`long`	`count(DBObject query, ReadPreference readPreference)`	Get the count of documents in collection that would match a criteria.
`void`	`createIndex(DBObject keys)`	Creates an index on the field specified, if that index does not already exist.
`void`	`createIndex(DBObject keys, DBObject options)`	Creates an index on the field specified, if that index does not already exist.
`void`	`createIndex(DBObject keys, String name)`	Forces creation of an index on a set of fields, if one does not already exist.
`void`	`createIndex(DBObject keys, String name, boolean unique)`	Forces creation of an index on a set of fields, if one does not already exist.
`void`	`createIndex(String name)`	Forces creation of an ascending index on a field with the default options.
`List`	`distinct(String fieldName)`	Find the distinct values for a specified field across a collection and returns the results in an array.
`List`	`distinct(String fieldName, DBCollectionDistinctOptions options)`	Find the distinct values for a specified field across a collection and returns the results in an array.
`List`	`distinct(String fieldName, DBObject query)`	Find the distinct values for a specified field across a collection and returns the results in an array.
`List`	`distinct(String fieldName, DBObject query, ReadPreference readPreference)`	Find the distinct values for a specified field across a collection and returns the results in an array.
`List`	`distinct(String fieldName, ReadPreference readPreference)`	Find the distinct values for a specified field across a collection and returns the results in an array.
`void`	`drop()`	Drops (deletes) this collection from the database.
`void`	`dropIndex(DBObject index)`	Drops an index from this collection.
`void`	`dropIndex(String indexName)`	Drops the index with the given name from this collection.
`void`	`dropIndexes()`	Drop all indexes on this collection.
`void`	`dropIndexes(String indexName)`	Drops the index with the given name from this collection.
`CommandResult`	`explainAggregate(List<? extends DBObject> pipeline, AggregationOptions options)`	Return the explain plan for the aggregation pipeline.
`DBCursor`	`find()`	Select all documents in collection and get a cursor to the selected documents.
`DBCursor`	`find(DBObject query)`	Select documents in collection and get a cursor to the selected documents.
`DBCursor`	`find(DBObject query, DBCollectionFindOptions options)`	Select documents in collection and get a cursor to the selected documents.
`DBCursor`	`find(DBObject query, DBObject projection)`	Select documents in collection and get a cursor to the selected documents.
`DBCursor`	`find(DBObject query, DBObject projection, int numToSkip, int batchSize)`	Deprecated. use `DBCursor.skip(int)` and `DBCursor.batchSize(int)` on the `DBCursor` returned from `find(DBObject, DBObject)`
`DBCursor`	`find(DBObject query, DBObject projection, int numToSkip, int batchSize, int options)`	Deprecated. use `DBCursor.skip(int)`, `DBCursor.batchSize(int)` and `DBCursor.setOptions(int)` on the `DBCursor` returned from `find(DBObject, DBObject)`
`DBObject`	`findAndModify(DBObject query, DBCollectionFindAndModifyOptions options)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject update)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject sort, DBObject update)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject fields, DBObject sort, boolean remove, DBObject update, boolean returnNew, boolean upsert)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject fields, DBObject sort, boolean remove, DBObject update, boolean returnNew, boolean upsert, boolean bypassDocumentValidation, long maxTime, TimeUnit maxTimeUnit)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject fields, DBObject sort, boolean remove, DBObject update, boolean returnNew, boolean upsert, boolean bypassDocumentValidation, long maxTime, TimeUnit maxTimeUnit, WriteConcern writeConcern)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject fields, DBObject sort, boolean remove, DBObject update, boolean returnNew, boolean upsert, long maxTime, TimeUnit maxTimeUnit)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject fields, DBObject sort, boolean remove, DBObject update, boolean returnNew, boolean upsert, long maxTime, TimeUnit maxTimeUnit, WriteConcern writeConcern)`	Atomically modify and return a single document.
`DBObject`	`findAndModify(DBObject query, DBObject fields, DBObject sort, boolean remove, DBObject update, boolean returnNew, boolean upsert, WriteConcern writeConcern)`	Atomically modify and return a single document.
`DBObject`	`findAndRemove(DBObject query)`	Atomically remove and return a single document.
`DBObject`	`findOne()`	Get a single document from collection.
`DBObject`	`findOne(DBObject query)`	Get a single document from collection.
`DBObject`	`findOne(DBObject query, DBCollectionFindOptions findOptions)`	Get a single document from collection.
`DBObject`	`findOne(DBObject query, DBObject projection)`	Get a single document from collection.
`DBObject`	`findOne(DBObject query, DBObject projection, DBObject sort)`	Get a single document from collection.
`DBObject`	`findOne(DBObject query, DBObject projection, DBObject sort, ReadPreference readPreference)`	Get a single document from collection.
`DBObject`	`findOne(DBObject query, DBObject projection, ReadPreference readPreference)`	Get a single document from collection.
`DBObject`	`findOne(Object id)`	Get a single document from collection by '_id'.
`DBObject`	`findOne(Object id, DBObject projection)`	Get a single document from collection by '_id'.
`DBCollection`	`getCollection(String name)`	Find a collection that is prefixed with this collection's name.
`long`	`getCount()`	Get the count of documents in collection.
`long`	`getCount(DBObject query)`	Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBCollectionCountOptions options)`	Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject projection)`	Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject projection, long limit, long skip)`	Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject projection, long limit, long skip, ReadPreference readPreference)`	Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject projection, ReadPreference readPreference)`	Get the count of documents in collection that would match a criteria.
`long`	`getCount(ReadPreference readPreference)`	Get the count of documents in collection.
`DB`	`getDB()`	Returns the database this collection is a member of.
`DBDecoderFactory`	`getDBDecoderFactory()`	Get the decoder factory for this collection.
`DBEncoderFactory`	`getDBEncoderFactory()`	Get the encoder factory for this collection.
`String`	`getFullName()`	Get the full name of a collection, with the database name as a prefix.
`List<DBObject>`	`getHintFields()`	Get hint fields for this collection (used to optimize queries).
`List<DBObject>`	`getIndexInfo()`	Return a list of the indexes for this collection.
`protected Class<? extends DBObject>`	`getInternalClass(String path)`	Gets the internal class for the given path in the document hierarchy
`String`	`getName()`	Get the name of a collection.
`Class`	`getObjectClass()`	Gets the default class for objects in the collection
`int`	`getOptions()`	Gets the default query options
`ReadConcern`	`getReadConcern()`	Get the read concern for this collection.
`ReadPreference`	`getReadPreference()`	Gets the `ReadPreference`.
`CommandResult`	`getStats()`	The collStats command returns a variety of storage statistics for a given collection
`WriteConcern`	`getWriteConcern()`	Get the `WriteConcern` for this collection.
`DBObject`	`group(DBObject key, DBObject cond, DBObject initial, String reduce)`	Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums.
`DBObject`	`group(DBObject key, DBObject cond, DBObject initial, String reduce, String finalize)`	Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums.
`DBObject`	`group(DBObject key, DBObject cond, DBObject initial, String reduce, String finalize, ReadPreference readPreference)`	Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums.
`DBObject`	`group(GroupCommand cmd)`	Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums.
`DBObject`	`group(GroupCommand cmd, ReadPreference readPreference)`	Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums.
`BulkWriteOperation`	`initializeOrderedBulkOperation()`	Creates a builder for an ordered bulk write operation, consisting of an ordered collection of write requests, which can be any combination of inserts, updates, replaces, or removes.
`BulkWriteOperation`	`initializeUnorderedBulkOperation()`	Creates a builder for an unordered bulk operation, consisting of an unordered collection of write requests, which can be any combination of inserts, updates, replaces, or removes.
`WriteResult`	`insert(DBObject... documents)`	Insert documents into a collection.
`WriteResult`	`insert(DBObject[] documents, WriteConcern writeConcern)`	Insert documents into a collection.
`WriteResult`	`insert(DBObject[] documents, WriteConcern aWriteConcern, DBEncoder encoder)`	Insert documents into a collection.
`WriteResult`	`insert(DBObject document, WriteConcern writeConcern)`	Insert a document into a collection.
`WriteResult`	`insert(WriteConcern writeConcern, DBObject... documents)`	Insert documents into a collection.
`WriteResult`	`insert(List<? extends DBObject> documents)`	Insert documents into a collection.
`WriteResult`	`insert(List<? extends DBObject> documents, InsertOptions insertOptions)`	Insert documents into a collection.
`WriteResult`	`insert(List<? extends DBObject> documents, WriteConcern aWriteConcern)`	Insert documents into a collection.
`WriteResult`	`insert(List<? extends DBObject> documents, WriteConcern aWriteConcern, DBEncoder dbEncoder)`	Insert documents into a collection.
`boolean`	`isCapped()`	Checks whether this collection is capped
`MapReduceOutput`	`mapReduce(MapReduceCommand command)`	Allows you to run map-reduce aggregation operations over a collection.
`MapReduceOutput`	`mapReduce(String map, String reduce, String outputTarget, DBObject query)`	Allows you to run map-reduce aggregation operations over a collection.
`MapReduceOutput`	`mapReduce(String map, String reduce, String outputTarget, MapReduceCommand.OutputType outputType, DBObject query)`	Allows you to run map-reduce aggregation operations over a collection and saves to a named collection.
`MapReduceOutput`	`mapReduce(String map, String reduce, String outputTarget, MapReduceCommand.OutputType outputType, DBObject query, ReadPreference readPreference)`	Allows you to run map-reduce aggregation operations over a collection and saves to a named collection.
`List<Cursor>`	`parallelScan(ParallelScanOptions options)`	Return a list of cursors over the collection that can be used to scan it in parallel.
`WriteResult`	`remove(DBObject query)`	Remove documents from a collection.
`WriteResult`	`remove(DBObject query, DBCollectionRemoveOptions options)`	Remove documents from a collection.
`WriteResult`	`remove(DBObject query, WriteConcern writeConcern)`	Remove documents from a collection.
`WriteResult`	`remove(DBObject query, WriteConcern writeConcern, DBEncoder encoder)`	Remove documents from a collection.
`DBCollection`	`rename(String newName)`	Change the name of an existing collection.
`DBCollection`	`rename(String newName, boolean dropTarget)`	Change the name of an existing collection.
`void`	`resetOptions()`	Resets the default query options
`WriteResult`	`save(DBObject document)`	Update an existing document or insert a document depending on the parameter.
`WriteResult`	`save(DBObject document, WriteConcern writeConcern)`	Update an existing document or insert a document depending on the parameter.
`void`	`setDBDecoderFactory(DBDecoderFactory factory)`	Set a custom decoder factory for this collection.
`void`	`setDBEncoderFactory(DBEncoderFactory factory)`	Set a custom encoder factory for this collection.
`void`	`setHintFields(List<? extends DBObject> indexes)`	Override MongoDB's default index selection and query optimization process.
`void`	`setInternalClass(String path, Class<? extends DBObject> aClass)`	Sets the internal class for the given path in the document hierarchy
`void`	`setObjectClass(Class<? extends DBObject> aClass)`	Sets a default class for objects in this collection; null resets the class to nothing.
`void`	`setOptions(int options)`	Sets the default query options, overwriting previous value.
`void`	`setReadConcern(ReadConcern readConcern)`	Sets the read concern for this collection.
`void`	`setReadPreference(ReadPreference preference)`	Sets the `ReadPreference` for this collection.
`void`	`setWriteConcern(WriteConcern writeConcern)`	Set the `WriteConcern` for this collection.
`void`	`slaveOk()`	Deprecated. Replaced with `ReadPreference.secondaryPreferred()`
`String`	`toString()`
`WriteResult`	`update(DBObject query, DBObject update)`	Modify an existing document.
`WriteResult`	`update(DBObject query, DBObject update, boolean upsert, boolean multi)`	Modify an existing document or documents in collection.
`WriteResult`	`update(DBObject query, DBObject update, boolean upsert, boolean multi, WriteConcern aWriteConcern)`	Modify an existing document or documents in collection.
`WriteResult`	`update(DBObject query, DBObject update, boolean upsert, boolean multi, WriteConcern concern, DBEncoder encoder)`	Modify an existing document or documents in collection.
`WriteResult`	`update(DBObject query, DBObject update, boolean upsert, boolean multi, WriteConcern concern, Boolean bypassDocumentValidation, DBEncoder encoder)`	Modify an existing document or documents in collection.
`WriteResult`	`update(DBObject query, DBObject update, DBCollectionUpdateOptions options)`	Modify an existing document or documents in collection.
`WriteResult`	`updateMulti(DBObject query, DBObject update)`	Modify documents in collection.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - ID_FIELD_NAME
```
public static final String ID_FIELD_NAME
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - DBCollection
```
protected DBCollection(DB database,
                       String name)
```
    Initializes a new collection. No operation is actually performed on the database.
    
    Parameters:
    
    database - database in which to create the collection
    
    name - the name of the collection
- Method Detail
  - insert
```
public WriteResult insert(DBObject document,
                          WriteConcern writeConcern)
```
    Insert a document into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    Parameters:
    
    document - DBObject to be inserted
    
    writeConcern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(DBObject... documents)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added. Collection wide WriteConcern will be used.
    
    Parameters:
    
    documents - DBObject's to be inserted
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(WriteConcern writeConcern,
                          DBObject... documents)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    Parameters:
    
    documents - DBObject's to be inserted
    
    writeConcern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(DBObject[] documents,
                          WriteConcern writeConcern)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    Parameters:
    
    documents - DBObject's to be inserted
    
    writeConcern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(List<? extends DBObject> documents)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    Parameters:
    
    documents - list of DBObject to be inserted
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(List<? extends DBObject> documents,
                          WriteConcern aWriteConcern)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    Parameters:
    
    documents - list of DBObject's to be inserted
    
    aWriteConcern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(DBObject[] documents,
                          WriteConcern aWriteConcern,
                          DBEncoder encoder)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    Parameters:
    
    documents - DBObject's to be inserted
    
    aWriteConcern - WriteConcern to be used during operation
    
    encoder - DBEncoder to be used
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(List<? extends DBObject> documents,
                          WriteConcern aWriteConcern,
                          @Nullable
                          DBEncoder dbEncoder)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    Parameters:
    
    documents - a list of DBObject's to be inserted
    
    aWriteConcern - WriteConcern to be used during operation
    
    dbEncoder - DBEncoder to be used
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - insert
```
public WriteResult insert(List<? extends DBObject> documents,
                          InsertOptions insertOptions)
```
    Insert documents into a collection. If the collection does not exists on the server, then it will be created. If the new document does not contain an '_id' field, it will be added.
    
    If the value of the continueOnError property of the given InsertOptions is true, that value will override the value of the continueOnError property of the given WriteConcern. Otherwise, the value of the continueOnError property of the given WriteConcern will take effect.
    
    Parameters:
    
    documents - a list of DBObject's to be inserted
    
    insertOptions - the options to use for the insert
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Insert Documents
  - save
```
public WriteResult save(DBObject document)
```
    Update an existing document or insert a document depending on the parameter. If the document does not contain an '_id' field, then the method performs an insert with the specified fields in the document as well as an '_id' field with a unique objectId value. If the document contains an '_id' field, then the method performs an upsert querying the collection on the '_id' field:
    - If a document does not exist with the specified '_id' value, the method performs an insert with the specified fields in the document.
    - If a document exists with the specified '_id' value, the method performs an update, replacing all field in the existing record with the fields from the document.
    Parameters:
    
    document - DBObject to save to the collection.
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert or update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Save
  - save
```
public WriteResult save(DBObject document,
                        WriteConcern writeConcern)
```
    Update an existing document or insert a document depending on the parameter. If the document does not contain an '_id' field, then the method performs an insert with the specified fields in the document as well as an '_id' field with a unique objectId value. If the document contains an '_id' field, then the method performs an upsert querying the collection on the '_id' field:
    - If a document does not exist with the specified '_id' value, the method performs an insert with the specified fields in the document.
    - If a document exists with the specified '_id' value, the method performs an update, replacing all field in the existing record with the fields from the document.
    Parameters:
    
    document - DBObject to save to the collection.
    
    writeConcern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the insert or update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Save
  - update
```
public WriteResult update(DBObject query,
                          DBObject update,
                          boolean upsert,
                          boolean multi,
                          WriteConcern aWriteConcern)
```
    Modify an existing document or documents in collection. The query parameter employs the same query selectors, as used in find().
    
    Parameters:
    
    query - the selection criteria for the update
    
    update - the modifications to apply
    
    upsert - when true, inserts a document if no document matches the update query criteria
    
    multi - when true, updates all documents in the collection that match the update query criteria, otherwise only updates one
    
    aWriteConcern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Modify Documents
  - update
```
public WriteResult update(DBObject query,
                          DBObject update,
                          boolean upsert,
                          boolean multi,
                          WriteConcern concern,
                          @Nullable
                          DBEncoder encoder)
```
    Modify an existing document or documents in collection. By default the method updates a single document. The query parameter employs the same query selectors, as used in find().
    
    Parameters:
    
    query - the selection criteria for the update
    
    update - the modifications to apply
    
    upsert - when true, inserts a document if no document matches the update query criteria
    
    multi - when true, updates all documents in the collection that match the update query criteria, otherwise only updates one
    
    concern - WriteConcern to be used during operation
    
    encoder - DBEncoder to be used
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Modify Documents
  - update
```
public WriteResult update(DBObject query,
                          DBObject update,
                          boolean upsert,
                          boolean multi,
                          WriteConcern concern,
                          @Nullable
                          Boolean bypassDocumentValidation,
                          @Nullable
                          DBEncoder encoder)
```
    Modify an existing document or documents in collection. By default the method updates a single document. The query parameter employs the same query selectors, as used in find(DBObject).
    
    Parameters:
    
    query - the selection criteria for the update
    
    update - the modifications to apply
    
    upsert - when true, inserts a document if no document matches the update query criteria
    
    multi - when true, updates all documents in the collection that match the update query criteria, otherwise only updates one
    
    concern - WriteConcern to be used during operation
    
    bypassDocumentValidation - whether to bypass document validation.
    
    encoder - the DBEncoder to use
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    2.14
    
    MongoDB documentation
    Modify
  - update
```
public WriteResult update(DBObject query,
                          DBObject update,
                          boolean upsert,
                          boolean multi)
```
    Modify an existing document or documents in collection. The query parameter employs the same query selectors, as used in find().
    
    Parameters:
    
    query - the selection criteria for the update
    
    update - the modifications to apply
    
    upsert - when true, inserts a document if no document matches the update query criteria
    
    multi - when true, updates all documents in the collection that match the update query criteria, otherwise only updates one
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Modify Documents
  - update
```
public WriteResult update(DBObject query,
                          DBObject update)
```
    Modify an existing document. The query parameter employs the same query selectors, as used in find().
    
    Parameters:
    
    query - the selection criteria for the update
    
    update - the modifications to apply
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Modify Documents
  - updateMulti
```
public WriteResult updateMulti(DBObject query,
                               DBObject update)
```
    Modify documents in collection. The query parameter employs the same query selectors, as used in find().
    
    Parameters:
    
    query - the selection criteria for the update
    
    update - the modifications to apply
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Modify Documents
  - update
```
public WriteResult update(DBObject query,
                          DBObject update,
                          DBCollectionUpdateOptions options)
```
    Modify an existing document or documents in collection.
    
    Parameters:
    
    query - the selection criteria for the update
    
    update - the modifications to apply
    
    options - the options to apply to the update operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    DuplicateKeyException - if the write failed to a duplicate unique key
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    3.4
    
    MongoDB documentation
    Modify
  - remove
```
public WriteResult remove(DBObject query)
```
    Remove documents from a collection.
    
    Parameters:
    
    query - the deletion criteria using query operators. Omit the query parameter or pass an empty document to delete all documents in the collection.
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the delete command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Remove Documents
  - remove
```
public WriteResult remove(DBObject query,
                          WriteConcern writeConcern)
```
    Remove documents from a collection.
    
    Parameters:
    
    query - the deletion criteria using query operators. Omit the query parameter or pass an empty document to delete all documents in the collection.
    
    writeConcern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the delete command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Remove Documents
  - remove
```
public WriteResult remove(DBObject query,
                          WriteConcern writeConcern,
                          DBEncoder encoder)
```
    Remove documents from a collection.
    
    Parameters:
    
    query - the deletion criteria using query operators. Omit the query parameter or pass an empty document to delete all documents in the collection.
    
    writeConcern - WriteConcern to be used during operation
    
    encoder - DBEncoder to be used
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the delete command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Remove Documents
  - remove
```
public WriteResult remove(DBObject query,
                          DBCollectionRemoveOptions options)
```
    Remove documents from a collection.
    
    Parameters:
    
    query - the deletion criteria using query operators. Omit the query parameter or pass an empty document to delete all documents in the collection.
    
    options - the options to apply to the delete operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the delete command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    3.4
    
    MongoDB documentation
    Remove Documents
  - find
```
@Deprecated
public DBCursor find(DBObject query,
                     DBObject projection,
                     int numToSkip,
                     int batchSize,
                     int options)
```
    Deprecated. use DBCursor.skip(int), DBCursor.batchSize(int) and DBCursor.setOptions(int) on the DBCursor returned from find(DBObject, DBObject)
    
    Select documents in collection and get a cursor to the selected documents.
    
    Parameters:
    
    query - the selection criteria using query operators. Omit the query parameter or pass an empty document to return all documents in the collection.
    
    projection - specifies which fields MongoDB will return from the documents in the result set.
    
    numToSkip - number of documents to skip
    
    batchSize - see DBCursor.batchSize(int) for more information
    
    options - query options to be used
    
    Returns:
    
    A cursor to the documents that match the query criteria
    
    MongoDB documentation
    Querying
  - find
```
@Deprecated
public DBCursor find(DBObject query,
                     DBObject projection,
                     int numToSkip,
                     int batchSize)
```
    Deprecated. use DBCursor.skip(int) and DBCursor.batchSize(int) on the DBCursor returned from find(DBObject, DBObject)
    
    Select documents in collection and get a cursor to the selected documents.
    
    Parameters:
    
    query - the selection criteria using query operators. Omit the query parameter or pass an empty document to return all documents in the collection.
    
    projection - specifies which fields MongoDB will return from the documents in the result set.
    
    numToSkip - number of documents to skip
    
    batchSize - see DBCursor.batchSize(int) for more information
    
    Returns:
    
    A cursor to the documents that match the query criteria
    
    MongoDB documentation
    Querying
  - find
```
public DBCursor find(DBObject query)
```
    Select documents in collection and get a cursor to the selected documents.
    
    Parameters:
    
    query - the selection criteria using query operators. Omit the query parameter or pass an empty document to return all documents in the collection.
    
    Returns:
    
    A cursor to the documents that match the query criteria
    
    MongoDB documentation
    Querying
  - find
```
public DBCursor find(DBObject query,
                     DBObject projection)
```
    Select documents in collection and get a cursor to the selected documents.
    
    Parameters:
    
    query - the selection criteria using query operators. Omit the query parameter or pass an empty document to return all documents in the collection.
    
    projection - specifies which fields MongoDB will return from the documents in the result set.
    
    Returns:
    
    A cursor to the documents that match the query criteria
    
    MongoDB documentation
    Querying
  - find
```
public DBCursor find()
```
    Select all documents in collection and get a cursor to the selected documents.
    
    Returns:
    
    A cursor to the documents that match the query criteria
    
    MongoDB documentation
    Querying
  - find
```
public DBCursor find(@Nullable
                     DBObject query,
                     DBCollectionFindOptions options)
```
    Select documents in collection and get a cursor to the selected documents.
    
    Parameters:
    
    query - the selection criteria using query operators. Omit the query parameter or pass an empty document to return all documents in the collection.
    
    options - the options for the find operation.
    
    Returns:
    
    A cursor to the documents that match the query criteria
    
    Since:
    
    3.4
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne()
```
    Get a single document from collection.
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(DBObject query)
```
    Get a single document from collection.
    
    Parameters:
    
    query - the selection criteria using query operators.
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(DBObject query,
                        DBObject projection)
```
    Get a single document from collection.
    
    Parameters:
    
    query - the selection criteria using query operators.
    
    projection - specifies which fields MongoDB will return from the documents in the result set.
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(DBObject query,
                        DBObject projection,
                        DBObject sort)
```
    Get a single document from collection.
    
    Parameters:
    
    query - the selection criteria using query operators.
    
    projection - specifies which fields MongoDB will return from the documents in the result set.
    
    sort - A document whose fields specify the attributes on which to sort the result set.
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(DBObject query,
                        DBObject projection,
                        ReadPreference readPreference)
```
    Get a single document from collection.
    
    Parameters:
    
    query - the selection criteria using query operators.
    
    projection - specifies which fields MongoDB will return from the documents in the result set.
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(@Nullable
                        DBObject query,
                        @Nullable
                        DBObject projection,
                        @Nullable
                        DBObject sort,
                        ReadPreference readPreference)
```
    Get a single document from collection.
    
    Parameters:
    
    query - the selection criteria using query operators.
    
    projection - specifies which projection MongoDB will return from the documents in the result set.
    
    sort - A document whose fields specify the attributes on which to sort the result set.
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(Object id)
```
    Get a single document from collection by '_id'.
    
    Parameters:
    
    id - value of '_id' field of a document we are looking for
    
    Returns:
    
    A document with '_id' provided as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(Object id,
                        DBObject projection)
```
    Get a single document from collection by '_id'.
    
    Parameters:
    
    id - value of '_id' field of a document we are looking for
    
    projection - specifies which projection MongoDB will return from the documents in the result set.
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    MongoDB documentation
    Querying
  - findOne
```
@Nullable
public DBObject findOne(@Nullable
                        DBObject query,
                        DBCollectionFindOptions findOptions)
```
    Get a single document from collection.
    
    Parameters:
    
    query - the selection criteria using query operators.
    
    findOptions - the options for the find operation.
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method.
    
    Since:
    
    3.4
    
    MongoDB documentation
    Querying
  - count
```
public long count()
```
    Same as getCount()
    
    Returns:
    
    the number of documents in collection
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - count
```
public long count(@Nullable
                  DBObject query)
```
    Same as getCount(DBObject)
    
    Parameters:
    
    query - specifies the selection criteria
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - count
```
public long count(@Nullable
                  DBObject query,
                  ReadPreference readPreference)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - count
```
public long count(@Nullable
                  DBObject query,
                  DBCollectionCountOptions options)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    options - the options for the count operation.
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    Since:
    
    3.4
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount()
```
    Get the count of documents in collection.
    
    Returns:
    
    the number of documents in collection
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount(ReadPreference readPreference)
```
    Get the count of documents in collection.
    
    Parameters:
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents in collection
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount(@Nullable
                     DBObject query)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount(@Nullable
                     DBObject query,
                     DBObject projection)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    projection - this is ignored
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount(@Nullable
                     DBObject query,
                     @Nullable
                     DBObject projection,
                     ReadPreference readPreference)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    projection - this is ignored
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount(@Nullable
                     DBObject query,
                     @Nullable
                     DBObject projection,
                     long limit,
                     long skip)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    projection - this is ignored
    
    limit - limit the count to this value
    
    skip - number of documents to skip
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount(@Nullable
                     DBObject query,
                     @Nullable
                     DBObject projection,
                     long limit,
                     long skip,
                     ReadPreference readPreference)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    projection - this is ignored
    
    limit - limit the count to this value
    
    skip - number of documents to skip
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Count
  - getCount
```
public long getCount(@Nullable
                     DBObject query,
                     DBCollectionCountOptions options)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    options - the options for the count operation.
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException - if the operation failed
    
    Since:
    
    3.4
    
    MongoDB documentation
    Count
  - rename
```
public DBCollection rename(String newName)
```
    Change the name of an existing collection.
    
    Parameters:
    
    newName - specifies the new name of the collection
    
    Returns:
    
    the collection with new name
    
    Throws:
    
    MongoException - if newName is the name of an existing collection.
    
    MongoDB documentation
    Rename Collection
  - rename
```
public DBCollection rename(String newName,
                           boolean dropTarget)
```
    Change the name of an existing collection.
    
    Parameters:
    
    newName - specifies the new name of the collection
    
    dropTarget - If true, mongod will drop the collection with the target name if it exists
    
    Returns:
    
    the collection with new name
    
    Throws:
    
    MongoException - if target is the name of an existing collection and dropTarget=false.
    
    MongoDB documentation
    Rename Collection
  - group
```
public DBObject group(DBObject key,
                      DBObject cond,
                      DBObject initial,
                      String reduce)
```
    Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums. This is analogous to a SELECT ... GROUP BY statement in SQL.
    
    Parameters:
    
    key - specifies one or more document fields to group
    
    cond - specifies the selection criteria to determine which documents in the collection to process
    
    initial - initializes the aggregation result document
    
    reduce - specifies an $reduce function, that operates on the documents during the grouping operation
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    MongoDB documentation
    Group Command
  - group
```
public DBObject group(DBObject key,
                      DBObject cond,
                      DBObject initial,
                      String reduce,
                      @Nullable
                      String finalize)
```
    Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums. This is analogous to a SELECT ... GROUP BY statement in SQL.
    
    Parameters:
    
    key - specifies one or more document fields to group
    
    cond - specifies the selection criteria to determine which documents in the collection to process
    
    initial - initializes the aggregation result document
    
    reduce - specifies an $reduce Javascript function, that operates on the documents during the grouping operation
    
    finalize - specifies a Javascript function that runs each item in the result set before final value will be returned
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    MongoDB documentation
    Group Command
  - group
```
public DBObject group(DBObject key,
                      DBObject cond,
                      DBObject initial,
                      String reduce,
                      @Nullable
                      String finalize,
                      ReadPreference readPreference)
```
    Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums. This is analogous to a SELECT ... GROUP BY statement in SQL.
    
    Parameters:
    
    key - specifies one or more document fields to group
    
    cond - specifies the selection criteria to determine which documents in the collection to process
    
    initial - initializes the aggregation result document
    
    reduce - specifies an $reduce Javascript function, that operates on the documents during the grouping operation
    
    finalize - specifies a Javascript function that runs each item in the result set before final value will be returned
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    MongoDB documentation
    Group Command
  - group
```
public DBObject group(GroupCommand cmd)
```
    Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums. This is analogous to a SELECT ... GROUP BY statement in SQL.
    
    Parameters:
    
    cmd - the group command
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    MongoDB documentation
    Group Command
  - group
```
public DBObject group(GroupCommand cmd,
                      ReadPreference readPreference)
```
    Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums. This is analogous to a SELECT ... GROUP BY statement in SQL.
    
    Parameters:
    
    cmd - the group command
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    MongoDB documentation
    Group Command
  - distinct
```
public List distinct(String fieldName)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    fieldName - Specifies the field for which to return the distinct values.
    
    Returns:
    
    a List of the distinct values
    
    MongoDB documentation
    Distinct Command
  - distinct
```
public List distinct(String fieldName,
                     ReadPreference readPreference)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    fieldName - Specifies the field for which to return the distinct values
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    a List of the distinct values
    
    MongoDB documentation
    Distinct Command
  - distinct
```
public List distinct(String fieldName,
                     DBObject query)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    fieldName - Specifies the field for which to return the distinct values
    
    query - specifies the selection query to determine the subset of documents from which to retrieve the distinct values
    
    Returns:
    
    an array of the distinct values
    
    MongoDB documentation
    Distinct Command
  - distinct
```
public List distinct(String fieldName,
                     DBObject query,
                     ReadPreference readPreference)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    fieldName - Specifies the field for which to return the distinct values
    
    query - specifies the selection query to determine the subset of documents from which to retrieve the distinct values
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    A List of the distinct values
    
    MongoDB documentation
    Distinct Command
  - distinct
```
public List distinct(String fieldName,
                     DBCollectionDistinctOptions options)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    fieldName - Specifies the field for which to return the distinct values
    
    options - the options to apply for this operation
    
    Returns:
    
    A List of the distinct values
    
    Since:
    
    3.4
    
    MongoDB documentation
    Distinct Command
  - mapReduce
```
public MapReduceOutput mapReduce(String map,
                                 String reduce,
                                 String outputTarget,
                                 DBObject query)
```
    Allows you to run map-reduce aggregation operations over a collection.
    
    Parameters:
    
    map - a JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
    
    reduce - a JavaScript function that "reduces" to a single object all the values associated with a particular key.
    
    outputTarget - specifies the location of the result of the map-reduce operation.
    
    query - specifies the selection criteria using query operators for determining the documents input to the map function.
    
    Returns:
    
    a MapReduceOutput which contains the results of this map reduce operation
    
    MongoDB documentation
    Map-Reduce
  - mapReduce
```
public MapReduceOutput mapReduce(String map,
                                 String reduce,
                                 String outputTarget,
                                 MapReduceCommand.OutputType outputType,
                                 DBObject query)
```
    Allows you to run map-reduce aggregation operations over a collection and saves to a named collection.
    
    Parameters:
    
    map - a JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
    
    reduce - a JavaScript function that "reduces" to a single object all the values associated with a particular key.
    
    outputTarget - specifies the location of the result of the map-reduce operation.
    
    outputType - specifies the type of job output
    
    query - specifies the selection criteria using query operators for determining the documents input to the map function.
    
    Returns:
    
    a MapReduceOutput which contains the results of this map reduce operation
    
    MongoDB documentation
    Map-Reduce
  - mapReduce
```
public MapReduceOutput mapReduce(String map,
                                 String reduce,
                                 String outputTarget,
                                 MapReduceCommand.OutputType outputType,
                                 DBObject query,
                                 ReadPreference readPreference)
```
    Allows you to run map-reduce aggregation operations over a collection and saves to a named collection.
    
    Parameters:
    
    map - a JavaScript function that associates or "maps" a value with a key and emits the key and value pair.
    
    reduce - a JavaScript function that "reduces" to a single object all the values associated with a particular key.
    
    outputTarget - specifies the location of the result of the map-reduce operation.
    
    outputType - specifies the type of job output
    
    query - specifies the selection criteria using query operators for determining the documents input to the map function.
    
    readPreference - the read preference specifying where to run the query. Only applied for Inline output type
    
    Returns:
    
    a MapReduceOutput which contains the results of this map reduce operation
    
    MongoDB documentation
    Map-Reduce
  - mapReduce
```
public MapReduceOutput mapReduce(MapReduceCommand command)
```
    Allows you to run map-reduce aggregation operations over a collection.
    
    Parameters:
    
    command - specifies the details of the Map Reduce operation to perform
    
    Returns:
    
    a MapReduceOutput containing the results of the map reduce operation
    
    MongoDB documentation
    Map-Reduce
  - aggregate
```
@Deprecated
public AggregationOutput aggregate(DBObject firstOp,
                                   DBObject... additionalOps)
```
    Deprecated. Use aggregate(List, AggregationOptions) instead
    
    Method implements aggregation framework.
    
    Parameters:
    
    firstOp - requisite first operation to be performed in the aggregation pipeline
    
    additionalOps - additional operations to be performed in the aggregation pipeline
    
    Returns:
    
    the aggregation operation's result set
    
    MongoDB documentation
    Aggregation
    Since server release
    2.2
  - aggregate
```
@Deprecated
public AggregationOutput aggregate(List<? extends DBObject> pipeline)
```
    Deprecated. Use aggregate(List, AggregationOptions) instead
    
    Method implements aggregation framework.
    
    Parameters:
    
    pipeline - operations to be performed in the aggregation pipeline
    
    Returns:
    
    the aggregation's result set
    
    MongoDB documentation
    Aggregation
    Since server release
    2.2
  - aggregate
```
@Deprecated
public AggregationOutput aggregate(List<? extends DBObject> pipeline,
                                   ReadPreference readPreference)
```
    Deprecated. Use aggregate(List, AggregationOptions, ReadPreference) )} instead
    
    Method implements aggregation framework.
    
    Parameters:
    
    pipeline - operations to be performed in the aggregation pipeline
    
    readPreference - the read preference specifying where to run the query
    
    Returns:
    
    the aggregation's result set
    
    MongoDB documentation
    Aggregation
    Since server release
    2.2
  - aggregate
```
public Cursor aggregate(List<? extends DBObject> pipeline,
                        AggregationOptions options)
```
    Method implements aggregation framework.
    
    Parameters:
    
    pipeline - operations to be performed in the aggregation pipeline
    
    options - options to apply to the aggregation
    
    Returns:
    
    the aggregation operation's result set
    
    MongoDB documentation
    Aggregation
    Since server release
    2.2
  - aggregate
```
public Cursor aggregate(List<? extends DBObject> pipeline,
                        AggregationOptions options,
                        ReadPreference readPreference)
```
    Method implements aggregation framework.
    
    Parameters:
    
    pipeline - operations to be performed in the aggregation pipeline
    
    options - options to apply to the aggregation
    
    readPreference - ReadPreference to be used for this operation
    
    Returns:
    
    the aggregation operation's result set
    
    MongoDB documentation
    Aggregation
    Since server release
    2.2
  - explainAggregate
```
public CommandResult explainAggregate(List<? extends DBObject> pipeline,
                                      AggregationOptions options)
```
    Return the explain plan for the aggregation pipeline.
    
    Parameters:
    
    pipeline - the aggregation pipeline to explain
    
    options - the options to apply to the aggregation
    
    Returns:
    
    the command result. The explain output may change from release to release, so best to simply log this.
    
    MongoDB documentation
    Aggregation
    Explain query
    Since server release
    2.6
  - parallelScan
```
public List<Cursor> parallelScan(ParallelScanOptions options)
```
    Return a list of cursors over the collection that can be used to scan it in parallel.
    
    Note: As of MongoDB 2.6, this method will work against a mongod, but not a mongos.
    
    Parameters:
    
    options - the parallel scan options
    
    Returns:
    
    a list of cursors, whose size may be less than the number requested
    
    Since:
    
    2.12
    
    MongoDB documentation
    Parallel Collection Scan
    Since server release
    2.6
  - getName
```
public String getName()
```
    Get the name of a collection.
    
    Returns:
    
    the name of a collection
  - getFullName
```
public String getFullName()
```
    Get the full name of a collection, with the database name as a prefix.
    
    Returns:
    
    the name of a collection
    
    MongoDB documentation
    Namespace
  - getCollection
```
public DBCollection getCollection(String name)
```
    Find a collection that is prefixed with this collection's name. A typical use of this might be
```
    DBCollection users = mongo.getCollection( "wiki" ).getCollection( "users" );
 
```
    Which is equivalent to
```
   DBCollection users = mongo.getCollection( "wiki.users" );
 
```
    Parameters:
    
    name - the name of the collection to find
    
    Returns:
    
    the matching collection
  - createIndex
```
public void createIndex(String name)
```
    Forces creation of an ascending index on a field with the default options.
    
    Parameters:
    
    name - name of field to index on
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Index Creation Tutorials
  - createIndex
```
public void createIndex(DBObject keys,
                        String name)
```
    Forces creation of an index on a set of fields, if one does not already exist.
    
    Parameters:
    
    keys - a document that contains pairs with the name of the field or fields to index and order of the index
    
    name - an identifier for the index. If null or empty, the default name will be used.
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Index Creation Tutorials
  - createIndex
```
public void createIndex(DBObject keys,
                        @Nullable
                        String name,
                        boolean unique)
```
    Forces creation of an index on a set of fields, if one does not already exist.
    
    Parameters:
    
    keys - a document that contains pairs with the name of the field or fields to index and order of the index
    
    name - an identifier for the index. If null or empty, the default name will be used.
    
    unique - if the index should be unique
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Index Creation Tutorials
  - createIndex
```
public void createIndex(DBObject keys)
```
    Creates an index on the field specified, if that index does not already exist.
    
    Parameters:
    
    keys - a document that contains pairs with the name of the field or fields to index and order of the index
    
    MongoDB documentation
    Index Creation Tutorials
  - createIndex
```
public void createIndex(DBObject keys,
                        DBObject options)
```
    Creates an index on the field specified, if that index does not already exist.
    Prior to MongoDB 3.0 the dropDups option could be used with unique indexes allowing documents with duplicate values to be dropped when building the index. Later versions of MongoDB will silently ignore this setting.
    
    Parameters:
    
    keys - a document that contains pairs with the name of the field or fields to index and order of the index
    
    options - a document that controls the creation of the index.
    
    MongoDB documentation
    Index Creation Tutorials
  - getHintFields
```
@Nullable
public List<DBObject> getHintFields()
```
    Get hint fields for this collection (used to optimize queries).
    
    Returns:
    
    a list of DBObject to be used as hints.
    
    MongoDB documentation
    $hint
  - setHintFields
```
public void setHintFields(List<? extends DBObject> indexes)
```
    Override MongoDB's default index selection and query optimization process.
    
    Parameters:
    
    indexes - list of indexes to "hint" or force MongoDB to use when performing the query.
    
    MongoDB documentation
    $hint
  - findAndModify
```
@Nullable
public DBObject findAndModify(@Nullable
                              DBObject query,
                              @Nullable
                              DBObject sort,
                              DBObject update)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    sort - determines which document the operation will modify if the query selects multiple documents
    
    update - the modifications to apply
    
    Returns:
    
    pre-modification document
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
@Nullable
public DBObject findAndModify(@Nullable
                              DBObject query,
                              DBObject update)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    update - the modifications to apply
    
    Returns:
    
    the document as it was before the modifications
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Find and Modify
  - findAndRemove
```
@Nullable
public DBObject findAndRemove(@Nullable
                              DBObject query)
```
    Atomically remove and return a single document. The returned document is the original document before removal.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    Returns:
    
    the document as it was before the modifications
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
@Nullable
public DBObject findAndModify(@Nullable
                              DBObject query,
                              @Nullable
                              DBObject fields,
                              @Nullable
                              DBObject sort,
                              boolean remove,
                              @Nullable
                              DBObject update,
                              boolean returnNew,
                              boolean upsert)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    fields - a subset of fields to return
    
    sort - determines which document the operation will modify if the query selects multiple documents
    
    remove - when true, removes the selected document
    
    returnNew - when true, returns the modified document rather than the original
    
    update - the modifications to apply
    
    upsert - when true, operation creates a new document if the query returns no documents
    
    Returns:
    
    the document as it was before the modifications, unless returnNew is true, in which case it returns the document after the changes were made
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
@Nullable
public DBObject findAndModify(@Nullable
                              DBObject query,
                              @Nullable
                              DBObject fields,
                              @Nullable
                              DBObject sort,
                              boolean remove,
                              DBObject update,
                              boolean returnNew,
                              boolean upsert,
                              WriteConcern writeConcern)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    fields - a subset of fields to return
    
    sort - determines which document the operation will modify if the query selects multiple documents
    
    remove - when true, removes the selected document
    
    returnNew - when true, returns the modified document rather than the original
    
    update - the modifications to apply
    
    upsert - when true, operation creates a new document if the query returns no documents
    
    writeConcern - the write concern to apply to this operation
    
    Returns:
    
    the document as it was before the modifications, unless returnNew is true, in which case it returns the document after the changes were made
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    2.14
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
@Nullable
public DBObject findAndModify(@Nullable
                              DBObject query,
                              @Nullable
                              DBObject fields,
                              @Nullable
                              DBObject sort,
                              boolean remove,
                              @Nullable
                              DBObject update,
                              boolean returnNew,
                              boolean upsert,
                              long maxTime,
                              TimeUnit maxTimeUnit)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    fields - a subset of fields to return
    
    sort - determines which document the operation will modify if the query selects multiple documents
    
    remove - when true, removes the selected document
    
    returnNew - when true, returns the modified document rather than the original
    
    update - the modifications to apply
    
    upsert - when true, operation creates a new document if the query returns no documents
    
    maxTime - the maximum time that the server will allow this operation to execute before killing it. A non-zero value requires a server version >= 2.6
    
    maxTimeUnit - the unit that maxTime is specified in
    
    Returns:
    
    the document as it was before the modifications, unless returnNew is true, in which case it returns the document after the changes were made
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    2.12.0
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
@Nullable
public DBObject findAndModify(@Nullable
                              DBObject query,
                              @Nullable
                              DBObject fields,
                              @Nullable
                              DBObject sort,
                              boolean remove,
                              @Nullable
                              DBObject update,
                              boolean returnNew,
                              boolean upsert,
                              long maxTime,
                              TimeUnit maxTimeUnit,
                              WriteConcern writeConcern)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    fields - a subset of fields to return
    
    sort - determines which document the operation will modify if the query selects multiple documents
    
    remove - when true, removes the selected document
    
    returnNew - when true, returns the modified document rather than the original
    
    update - performs an update of the selected document
    
    upsert - when true, operation creates a new document if the query returns no documents
    
    maxTime - the maximum time that the server will allow this operation to execute before killing it. A non-zero value requires a server version >= 2.6
    
    maxTimeUnit - the unit that maxTime is specified in
    
    writeConcern - the write concern to apply to this operation
    
    Returns:
    
    the document as it was before the modifications, unless returnNew is true, in which case it returns the document after the changes were made
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    2.14.0
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
@Nullable
public DBObject findAndModify(DBObject query,
                              DBObject fields,
                              DBObject sort,
                              boolean remove,
                              @Nullable
                              DBObject update,
                              boolean returnNew,
                              boolean upsert,
                              boolean bypassDocumentValidation,
                              long maxTime,
                              TimeUnit maxTimeUnit)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    fields - a subset of fields to return
    
    sort - determines which document the operation will modify if the query selects multiple documents
    
    remove - when true, removes the selected document
    
    returnNew - when true, returns the modified document rather than the original
    
    update - performs an update of the selected document
    
    upsert - when true, operation creates a new document if the query returns no documents
    
    bypassDocumentValidation - whether to bypass document validation.
    
    maxTime - the maximum time that the server will allow this operation to execute before killing it. A non-zero value requires a server version >= 2.6
    
    maxTimeUnit - the unit that maxTime is specified in
    
    Returns:
    
    the document as it was before the modifications, unless returnNew is true, in which case it returns the document after the changes were made
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    2.14.0
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
public DBObject findAndModify(@Nullable
                              DBObject query,
                              @Nullable
                              DBObject fields,
                              @Nullable
                              DBObject sort,
                              boolean remove,
                              @Nullable
                              DBObject update,
                              boolean returnNew,
                              boolean upsert,
                              boolean bypassDocumentValidation,
                              long maxTime,
                              TimeUnit maxTimeUnit,
                              WriteConcern writeConcern)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    fields - a subset of fields to return
    
    sort - determines which document the operation will modify if the query selects multiple documents
    
    remove - when true, removes the selected document
    
    returnNew - when true, returns the modified document rather than the original
    
    update - performs an update of the selected document
    
    upsert - when true, operation creates a new document if the query returns no documents
    
    bypassDocumentValidation - whether to bypass document validation.
    
    maxTime - the maximum time that the server will allow this operation to execute before killing it. A non-zero value requires a server version >= 2.6
    
    maxTimeUnit - the unit that maxTime is specified in
    
    writeConcern - the write concern to apply to this operation
    
    Returns:
    
    the document as it was before the modifications, unless returnNew is true, in which case it returns the document after the changes were made
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    2.14.0
    
    MongoDB documentation
    Find and Modify
  - findAndModify
```
public DBObject findAndModify(DBObject query,
                              DBCollectionFindAndModifyOptions options)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update.
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    options - the options regarding the find and modify operation
    
    Returns:
    
    the document as it was before the modifications, unless oprtions.returnNew is true, in which case it returns the document after the changes were made
    
    Throws:
    
    WriteConcernException - if the write failed due some other failure specific to the update command
    
    MongoException - if the operation failed for some other reason
    
    Since:
    
    3.4
    
    MongoDB documentation
    Find and Modify
  - getDB
```
public DB getDB()
```
    Returns the database this collection is a member of.
    
    Returns:
    
    this collection's database
    
    MongoDB documentation
    Database
  - getWriteConcern
```
public WriteConcern getWriteConcern()
```
    Get the WriteConcern for this collection.
    
    Returns:
    
    the default write concern for this collection
    
    MongoDB documentation
    Write Concern
  - setWriteConcern
```
public void setWriteConcern(WriteConcern writeConcern)
```
    Set the WriteConcern for this collection. Will be used for writes to this collection. Overrides any setting of write concern at the DB level.
    
    Parameters:
    
    writeConcern - WriteConcern to use
    
    MongoDB documentation
    Write Concern
  - getReadPreference
```
public ReadPreference getReadPreference()
```
    Gets the ReadPreference.
    
    Returns:
    
    the default read preference for this collection
    
    MongoDB documentation
    Read Preference
  - setReadPreference
```
public void setReadPreference(ReadPreference preference)
```
    Sets the ReadPreference for this collection. Will be used as default for reads from this collection; overrides DB and Connection level settings. See the documentation for ReadPreference for more information.
    
    Parameters:
    
    preference - ReadPreference to use
    
    MongoDB documentation
    Read Preference
  - setReadConcern
```
public void setReadConcern(ReadConcern readConcern)
```
    Sets the read concern for this collection.
    
    Parameters:
    
    readConcern - the read concern to use for this collection
    
    Since:
    
    3.3
    
    MongoDB documentation
    Read Concern
    Since server release
    3.2
  - getReadConcern
```
public ReadConcern getReadConcern()
```
    Get the read concern for this collection.
    
    Returns:
    
    the ReadConcern
    
    Since:
    
    3.3
    
    MongoDB documentation
    Read Concern
    Since server release
    3.2
  - slaveOk
```
@Deprecated
public void slaveOk()
```
    Deprecated. Replaced with ReadPreference.secondaryPreferred()
    
    Makes this query ok to run on a slave node
  - addOption
```
public void addOption(int option)
```
    Adds the given flag to the default query options.
    
    Parameters:
    
    option - value to be added
    
    MongoDB documentation
    Query Flags
  - resetOptions
```
public void resetOptions()
```
    Resets the default query options
    
    MongoDB documentation
    Query Flags
  - getOptions
```
public int getOptions()
```
    Gets the default query options
    
    Returns:
    
    bit vector of query options
    
    MongoDB documentation
    Query Flags
  - setOptions
```
public void setOptions(int options)
```
    Sets the default query options, overwriting previous value.
    
    Parameters:
    
    options - bit vector of query options
    
    MongoDB documentation
    Query Flags
  - drop
```
public void drop()
```
    Drops (deletes) this collection from the database. Use with care.
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Drop Command
  - getDBDecoderFactory
```
public DBDecoderFactory getDBDecoderFactory()
```
    Get the decoder factory for this collection. A null return value means that the default from MongoOptions is being used.
    
    Returns:
    
    the factory
  - setDBDecoderFactory
```
public void setDBDecoderFactory(@Nullable
                                DBDecoderFactory factory)
```
    Set a custom decoder factory for this collection. Set to null to use the default from MongoOptions.
    
    Parameters:
    
    factory - the factory to set.
  - getDBEncoderFactory
```
public DBEncoderFactory getDBEncoderFactory()
```
    Get the encoder factory for this collection. A null return value means that the default from MongoOptions is being used.
    
    Returns:
    
    the factory
  - setDBEncoderFactory
```
public void setDBEncoderFactory(@Nullable
                                DBEncoderFactory factory)
```
    Set a custom encoder factory for this collection. Set to null to use the default from MongoOptions.
    
    Parameters:
    
    factory - the factory to set.
  - getIndexInfo
```
public List<DBObject> getIndexInfo()
```
    Return a list of the indexes for this collection. Each object in the list is the "info document" from MongoDB
    
    Returns:
    
    list of index documents
    
    Throws:
    
    MongoException - if the operation failed
    
    MongoDB documentation
    Indexes
  - dropIndex
```
public void dropIndex(DBObject index)
```
    Drops an index from this collection. The DBObject index parameter must match the specification of the index to drop, i.e. correct key name and type must be specified.
    
    Parameters:
    
    index - the specification of the index to drop
    
    Throws:
    
    MongoException - if the index does not exist
    
    MongoDB documentation
    Indexes
  - dropIndex
```
public void dropIndex(String indexName)
```
    Drops the index with the given name from this collection.
    
    Parameters:
    
    indexName - name of index to drop
    
    Throws:
    
    MongoException - if the index does not exist
    
    MongoDB documentation
    Indexes
  - dropIndexes
```
public void dropIndexes()
```
    Drop all indexes on this collection. The default index on the _id field will not be deleted.
    
    MongoDB documentation
    Indexes
  - dropIndexes
```
public void dropIndexes(String indexName)
```
    Drops the index with the given name from this collection. This method is exactly the same as dropIndex(indexName).
    
    Parameters:
    
    indexName - name of index to drop
    
    Throws:
    
    MongoException - if the index does not exist
    
    MongoDB documentation
    Indexes
  - getStats
```
public CommandResult getStats()
```
    The collStats command returns a variety of storage statistics for a given collection
    
    Returns:
    
    a CommandResult containing the statistics about this collection
    
    MongoDB documentation
    collStats Command
  - isCapped
```
public boolean isCapped()
```
    Checks whether this collection is capped
    
    Returns:
    
    true if this is a capped collection
    
    MongoDB documentation
    Capped Collections
  - getObjectClass
```
public Class getObjectClass()
```
    Gets the default class for objects in the collection
    
    Returns:
    
    the class
  - setObjectClass
```
public void setObjectClass(Class<? extends DBObject> aClass)
```
    Sets a default class for objects in this collection; null resets the class to nothing.
    
    Parameters:
    
    aClass - the class
  - setInternalClass
```
public void setInternalClass(String path,
                             Class<? extends DBObject> aClass)
```
    Sets the internal class for the given path in the document hierarchy
    
    Parameters:
    
    path - the path to map the given Class to
    
    aClass - the Class to map the given path to
  - getInternalClass
```
protected Class<? extends DBObject> getInternalClass(String path)
```
    Gets the internal class for the given path in the document hierarchy
    
    Parameters:
    
    path - the path to map the given Class to
    
    Returns:
    
    the class for a given path in the hierarchy
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - initializeOrderedBulkOperation
```
public BulkWriteOperation initializeOrderedBulkOperation()
```
    Creates a builder for an ordered bulk write operation, consisting of an ordered collection of write requests, which can be any combination of inserts, updates, replaces, or removes. Write requests included in the bulk operations will be executed in order, and will halt on the first failure.
    
    Note: While this bulk write operation will execute on MongoDB 2.4 servers and below, the writes will be performed one at a time, as that is the only way to preserve the semantics of the value returned from execution or the exception thrown.
    
    Note: While a bulk write operation with a mix of inserts, updates, replaces, and removes is supported, the implementation will batch up consecutive requests of the same type and send them to the server one at a time. For example, if a bulk write operation consists of 10 inserts followed by 5 updates, followed by 10 more inserts, it will result in three round trips to the server.
    
    Returns:
    
    the builder
    
    Since:
    
    2.12
    
    MongoDB documentation
    initializeOrderedBulkOp()
  - initializeUnorderedBulkOperation
```
public BulkWriteOperation initializeUnorderedBulkOperation()
```
    Creates a builder for an unordered bulk operation, consisting of an unordered collection of write requests, which can be any combination of inserts, updates, replaces, or removes. Write requests included in the bulk operation will be executed in an undefined order, and all requests will be executed even if some fail.
    
    Note: While this bulk write operation will execute on MongoDB 2.4 servers and below, the writes will be performed one at a time, as that is the only way to preserve the semantics of the value returned from execution or the exception thrown.
    
    Returns:
    
    the builder
    
    Since:
    
    2.12
    
    MongoDB documentation
    initializeUnorderedBulkOp()

Class DBCollection

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ID_FIELD_NAME

Constructor Detail

DBCollection

Method Detail

insert

insert

insert

insert

insert

insert

insert

insert

insert

save

save

update

update

update

update

update

updateMulti

update

remove

remove

remove

remove

find

find

find

find

find

find

findOne

findOne

findOne

findOne

findOne

findOne

findOne

findOne

findOne

count

count

count

count

getCount

getCount

getCount

getCount

getCount

getCount

getCount

getCount

rename

rename

group

group

group

group

group

distinct

distinct

distinct

distinct

distinct

mapReduce

mapReduce

mapReduce

mapReduce

aggregate

aggregate

aggregate

aggregate

aggregate