DBCollection

java.lang.Object
- com.mongodb.DBCollection

public abstract class DBCollection
extends Object

This class provides a skeleton implementation of a database collection.

A typical invocation sequence is thus

 
 MongoClient mongoClient = new MongoClient(new ServerAddress("localhost", 27017));
 DB db = mongo.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);

MongoDB documentation: Collection

Field Summary

Fields
Modifier and Type	Field and Description
`protected String`	`_fullName` Deprecated. Please use `getFullName()` instead.
`protected List<DBObject>`	`_hintFields` Deprecated. Please use `setHintFields(java.util.List)` and `getHintFields()` instead.
`protected String`	`_name` Deprecated. Please use `getName()` instead.
`protected Class`	`_objectClass` Deprecated. Please use `getObjectClass()` and `setObjectClass(Class)` instead.

Constructor Summary

Constructors
Modifier Constructor and Description

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

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

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`protected DBObject`	`_checkObject(DBObject o, boolean canBeNull, boolean query)` Deprecated. This method should not be a part of API. If you override one of the `DBCollection` methods please rely on superclass implementation in checking argument correctness and validity.
`void`	`addOption(int option)` Adds the given flag to the default query options.
`AggregationOutput`	`aggregate(DBObject firstOp, DBObject... additionalOps)` Deprecated. Use `aggregate(java.util.List)` instead
`AggregationOutput`	`aggregate(List<DBObject> pipeline)` Method implements aggregation framework.
`Cursor`	`aggregate(List<DBObject> pipeline, AggregationOptions options)` Method implements aggregation framework.
`abstract Cursor`	`aggregate(List<DBObject> pipeline, AggregationOptions options, ReadPreference readPreference)` Method implements aggregation framework.
`AggregationOutput`	`aggregate(List<DBObject> pipeline, ReadPreference readPreference)` Method implements aggregation framework.
`Object`	`apply(DBObject document)` Deprecated. This method will be removed in a future release. There is no replacement.
`Object`	`apply(DBObject document, boolean ensureId)` Deprecated. This method will be removed in a future release. There is no replacement.
`protected boolean`	`checkReadOnly(boolean strict)` Deprecated. See `DB.setReadOnly(Boolean)`
`long`	`count()` Get the number of documents in the collection.
`long`	`count(DBObject query)` Get the count of documents in collection that would match a criteria.
`long`	`count(DBObject query, ReadPreference readPrefs)` Get the count of documents in collection that would match a criteria.
`void`	`createIndex(DBObject keys)` Forces creation of an index on a set of fields with the default options, if one does not already exist.
`void`	`createIndex(DBObject keys, DBObject options)` Forces creation of an index on a set of fields, if one does not already exist.
`abstract void`	`createIndex(DBObject keys, DBObject options, DBEncoder encoder)` Deprecated. use `createIndex(DBObject, com.mongodb.DBObject)` the encoder is not used.
`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 key)` Find the distinct values for a specified field across a collection and returns the results in an array.
`List`	`distinct(String key, DBObject query)` Find the distinct values for a specified field across a collection and returns the results in an array.
`List`	`distinct(String key, DBObject query, ReadPreference readPrefs)` Find the distinct values for a specified field across a collection and returns the results in an array.
`List`	`distinct(String key, ReadPreference readPrefs)` Find the distinct values for a specified field across a collection and returns the results in an array.
`protected abstract void`	`doapply(DBObject document)` Deprecated. This method will be removed in a future release. There is no replacement.
`void`	`drop()` Drops (deletes) this collection from the database.
`void`	`dropIndex(DBObject keys)` 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 name)` Drops the index with the given name from this collection.
`void`	`ensureIndex(DBObject keys)` Deprecated. use `createIndex(DBObject)` instead
`void`	`ensureIndex(DBObject keys, DBObject optionsIN)` Deprecated. use `createIndex(DBObject, DBObject)` instead
`void`	`ensureIndex(DBObject keys, String name)` Deprecated. use `createIndex(DBObject, DBObject)` instead
`void`	`ensureIndex(DBObject keys, String name, boolean unique)` Deprecated. use `createIndex(DBObject, String, boolean)` instead
`void`	`ensureIndex(String name)` Deprecated. use `createIndex(String)` instead
`boolean`	`equals(Object o)`
`CommandResult`	`explainAggregate(List<DBObject> pipeline, AggregationOptions options)` Return the explain plan for the aggregation pipeline.
`DBCursor`	`find()` Queries for all objects in this collection.
`DBCursor`	`find(DBObject ref)` Queries for an object in this collection.
`DBCursor`	`find(DBObject ref, DBObject keys)` Queries for an object in this collection.
`DBCursor`	`find(DBObject query, DBObject fields, 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 fields, 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, 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, long maxTime, TimeUnit maxTimeUnit)` Atomically modify and return a single document.
`DBObject`	`findAndRemove(DBObject query)` Atomically modify and return a single document.
`DBObject`	`findOne()` Returns a single object from this collection.
`DBObject`	`findOne(DBObject o)` Returns a single object from this collection matching the query.
`DBObject`	`findOne(DBObject o, DBObject fields)` Returns a single object from this collection matching the query.
`DBObject`	`findOne(DBObject o, DBObject fields, DBObject orderBy)` Returns a single object from this collection matching the query.
`DBObject`	`findOne(DBObject o, DBObject fields, DBObject orderBy, ReadPreference readPref)` Get a single document from collection.
`DBObject`	`findOne(DBObject o, DBObject fields, ReadPreference readPref)` 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'.
`static String`	`genIndexName(DBObject keys)` Deprecated. This method is NOT a part of public API and will be dropped in 3.x versions.
`DBCollection`	`getCollection(String n)` Find a collection that is prefixed with this collection's name.
`long`	`getCount()` Get the count of documents in a collection.
`long`	`getCount(DBObject query)` Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject fields)` Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject fields, long limit, long skip)` Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject fields, long limit, long skip, ReadPreference readPrefs)` Get the count of documents in collection that would match a criteria.
`long`	`getCount(DBObject query, DBObject fields, ReadPreference readPrefs)` Get the count of documents in collection that would match a criteria.
`long`	`getCount(ReadPreference readPrefs)` Get the count of documents in a 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.
`protected List<DBObject>`	`getHintFields()` Get hint fields for this collection (used to optimize queries).
`abstract List<DBObject>`	`getIndexInfo()` Return a list of the indexes for this collection.
`protected Class`	`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
`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 args)` Deprecated. use `group(com.mongodb.GroupCommand)` instead. This method will be removed in 3.0
`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 readPrefs)` 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 readPrefs)` Group documents in a collection by the specified key and performs simple aggregation functions such as computing counts and sums.
`int`	`hashCode()`
`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... arr)` Insert documents into a collection.
`WriteResult`	`insert(DBObject[] arr, WriteConcern concern)` Insert documents into a collection.
`WriteResult`	`insert(DBObject[] arr, WriteConcern concern, DBEncoder encoder)` Insert documents into a collection.
`WriteResult`	`insert(DBObject o, WriteConcern concern)` Insert a document into a collection.
`WriteResult`	`insert(List<DBObject> list)` Insert documents into a collection.
`WriteResult`	`insert(List<DBObject> documents, InsertOptions insertOptions)` Insert documents into a collection.
`WriteResult`	`insert(List<DBObject> list, WriteConcern concern)` Insert documents into a collection.
`abstract WriteResult`	`insert(List<DBObject> list, WriteConcern concern, DBEncoder encoder)` Insert documents into a collection.
`WriteResult`	`insert(WriteConcern concern, DBObject... arr)` Insert documents into a collection.
`boolean`	`isCapped()` Checks whether this collection is capped
`MapReduceOutput`	`mapReduce(DBObject command)` Deprecated. Use `mapReduce(MapReduceCommand)` instead
`MapReduceOutput`	`mapReduce(MapReduceCommand command)` 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, 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 readPrefs)` Allows you to run map-reduce aggregation operations over a collection and saves to a named collection.
`abstract 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 o)` Remove documents from a collection.
`WriteResult`	`remove(DBObject o, WriteConcern concern)` Remove documents from a collection.
`abstract WriteResult`	`remove(DBObject o, WriteConcern concern, DBEncoder encoder)` Remove documents from a collection.
`DBCollection`	`rename(String newName)` Calls `rename(java.lang.String, boolean)` with dropTarget=false
`DBCollection`	`rename(String newName, boolean dropTarget)` Renames of this collection to newName
`void`	`resetIndexCache()` Deprecated. This will be removed in 3.0
`void`	`resetOptions()` Resets the default query options
`WriteResult`	`save(DBObject jo)` Update an existing document or insert a document depending on the parameter.
`WriteResult`	`save(DBObject jo, WriteConcern concern)` Update an existing document or insert a document depending on the parameter.
`void`	`setDBDecoderFactory(DBDecoderFactory fact)` Set a customer decoder factory for this collection.
`void`	`setDBEncoderFactory(DBEncoderFactory fact)` Set a customer encoder factory for this collection.
`void`	`setHintFields(List<DBObject> indexes)` Override MongoDB's default index selection and query optimization process.
`void`	`setInternalClass(String path, Class c)` Sets the internal class for the given path in the document hierarchy
`void`	`setObjectClass(Class c)` 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`	`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 q, DBObject o)` Modify an existing document or documents in collection.
`WriteResult`	`update(DBObject q, DBObject o, boolean upsert, boolean multi)` Modify an existing document or documents in collection.
`WriteResult`	`update(DBObject q, DBObject o, boolean upsert, boolean multi, WriteConcern concern)` Modify an existing document or documents in collection.
`abstract WriteResult`	`update(DBObject q, DBObject o, boolean upsert, boolean multi, WriteConcern concern, DBEncoder encoder)` Modify an existing document or documents in collection.
`WriteResult`	`updateMulti(DBObject q, DBObject o)` Modify documents in collection.

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

- Field Detail
  - _name
```
@Deprecated
protected final String _name
```
    Deprecated. Please use getName() instead.
  - _fullName
```
@Deprecated
protected final String _fullName
```
    Deprecated. Please use getFullName() instead.
  - _hintFields
```
@Deprecated
protected List<DBObject> _hintFields
```
    Deprecated. Please use setHintFields(java.util.List) and getHintFields() instead.
  - _objectClass
```
@Deprecated
protected Class _objectClass
```
    Deprecated. Please use getObjectClass() and setObjectClass(Class) instead.
- Constructor Detail
  - DBCollection
```
protected DBCollection(DB base,
                       String name)
```
    Initializes a new collection. No operation is actually performed on the database.
    
    Parameters:
    
    base - database in which to create the collection
    
    name - the name of the collection
- Method Detail
  - insert
```
public WriteResult insert(DBObject[] arr,
                          WriteConcern concern)
```
    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:
    
    arr - DBObject's to be inserted
    
    concern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public WriteResult insert(DBObject[] arr,
                          WriteConcern concern,
                          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:
    
    arr - DBObject's to be inserted
    
    concern - WriteConcern to be used during operation
    
    encoder - DBEncoder to be used
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public WriteResult insert(DBObject o,
                          WriteConcern concern)
```
    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:
    
    o - DBObject to be inserted
    
    concern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public WriteResult insert(DBObject... arr)
```
    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:
    
    arr - DBObject's to be inserted
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public WriteResult insert(WriteConcern concern,
                          DBObject... arr)
```
    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:
    
    arr - DBObject's to be inserted
    
    concern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public WriteResult insert(List<DBObject> list)
```
    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:
    
    list - list of DBObject to be inserted
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public WriteResult insert(List<DBObject> list,
                          WriteConcern concern)
```
    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:
    
    list - list of DBObject's to be inserted
    
    concern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public abstract WriteResult insert(List<DBObject> list,
                                   WriteConcern concern,
                                   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:
    
    list - a list of DBObject's to be inserted
    
    concern - WriteConcern to be used during operation
    
    encoder - DBEncoder to use to serialise the documents
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert
  - insert
```
public WriteResult insert(List<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:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Insert Documents
  - update
```
public WriteResult update(DBObject q,
                          DBObject o,
                          boolean upsert,
                          boolean multi,
                          WriteConcern concern)
```
    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:
    
    q - the selection criteria for the update
    
    o - 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
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Modify
  - update
```
public abstract WriteResult update(DBObject q,
                                   DBObject o,
                                   boolean upsert,
                                   boolean multi,
                                   WriteConcern concern,
                                   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:
    
    q - the selection criteria for the update
    
    o - 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 - the DBEncoder to use
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Modify
  - update
```
public WriteResult update(DBObject q,
                          DBObject o,
                          boolean upsert,
                          boolean multi)
```
    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). Calls update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean, com.mongodb.WriteConcern) with default WriteConcern.
    
    Parameters:
    
    q - the selection criteria for the update
    
    o - 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:
    
    MongoException
    
    MongoDB documentation
    
    Modify
  - update
```
public WriteResult update(DBObject q,
                          DBObject o)
```
    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). Calls update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean) with upsert=false and multi=false
    
    Parameters:
    
    q - the selection criteria for the update
    
    o - the modifications to apply
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Modify
  - updateMulti
```
public WriteResult updateMulti(DBObject q,
                               DBObject o)
```
    Modify documents in collection. The query parameter employs the same query selectors, as used in find(). Calls update(com.mongodb.DBObject, com.mongodb.DBObject, boolean, boolean) with upsert=false and multi=true
    
    Parameters:
    
    q - the selection criteria for the update
    
    o - the modifications to apply
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Modify
  - doapply
```
@Deprecated
protected abstract void doapply(DBObject document)
```
    Deprecated. This method will be removed in a future release. There is no replacement.
    
    Method to be overridden if you need to add any fields to a given document before saving it to the collection.
    
    Parameters:
    
    document - object to which to add the fields
  - remove
```
public WriteResult remove(DBObject o,
                          WriteConcern concern)
```
    Remove documents from a collection.
    
    Parameters:
    
    o - the deletion criteria using query operators. Omit the query parameter or pass an empty document to delete all documents in the collection.
    
    concern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Remove
  - remove
```
public abstract WriteResult remove(DBObject o,
                                   WriteConcern concern,
                                   DBEncoder encoder)
```
    Remove documents from a collection.
    
    Parameters:
    
    o - the deletion criteria using query operators. Omit the query parameter or pass an empty document to delete all documents in the collection.
    
    concern - WriteConcern to be used during operation
    
    encoder - DBEncoder to be used
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Remove
  - remove
```
public WriteResult remove(DBObject o)
```
    Remove documents from a collection. Calls remove(com.mongodb.DBObject, com.mongodb.WriteConcern) with the default WriteConcern
    
    Parameters:
    
    o - 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:
    
    MongoException
    
    MongoDB documentation
    
    Remove
  - find
```
@Deprecated
public DBCursor find(DBObject query,
                                 DBObject fields,
                                 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)
    
    Calls find(com.mongodb.DBObject, com.mongodb.DBObject, int, int) and applies the query options
    
    Parameters:
    
    query - query used to search
    
    fields - the fields of matching objects to return
    
    numToSkip - number of objects to skip
    
    batchSize - the batch size. This option has a complex behavior, see DBCursor.batchSize(int)
    
    options - see Bytes QUERYOPTION_*
    
    Returns:
    
    the cursor
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - find
```
@Deprecated
public DBCursor find(DBObject query,
                                 DBObject fields,
                                 int numToSkip,
                                 int batchSize)
```
    Deprecated. use DBCursor.skip(int) and DBCursor.batchSize(int) on the DBCursor returned from find(DBObject, DBObject)
    
    Finds objects from the database that match a query. A DBCursor object is returned, that can be iterated to go through the results.
    
    Parameters:
    
    query - query used to search
    
    fields - the fields of matching objects to return
    
    numToSkip - number of objects to skip
    
    batchSize - the batch size. This option has a complex behavior, see DBCursor.batchSize(int)
    
    Returns:
    
    the cursor
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - findOne
```
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
```
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
  - findAndModify
```
public DBObject findAndModify(DBObject query,
                              DBObject fields,
                              DBObject sort,
                              boolean remove,
                              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:
    
    MongoException
    
    MongoDB documentation
    
    Find and Modify
  - findAndModify
```
public 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. 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
    
    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
    
    Since:
    
    2.12.0
    
    MongoDB documentation
    
    Find and Modify
  - findAndModify
```
public DBObject findAndModify(DBObject query,
                              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. Calls findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean) with fields=null, remove=false, returnNew=false, upsert=false
    
    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:
    
    the document as it was before the modifications.
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Find and Modify
  - findAndModify
```
public DBObject findAndModify(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. Calls findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean) with fields=null, sort=null, remove=false, returnNew=false, upsert=false
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    update - the modifications to apply
    
    Returns:
    
    the document as it was before the modifications.
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Find and Modify
  - findAndRemove
```
public DBObject findAndRemove(DBObject query)
```
    Atomically modify and return a single document. By default, the returned document does not include the modifications made on the update. Calls findAndModify(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, boolean, com.mongodb.DBObject, boolean, boolean) with fields=null, sort=null, remove=true, returnNew=false, upsert=false
    
    Parameters:
    
    query - specifies the selection criteria for the modification
    
    Returns:
    
    the document as it was before it was removed
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Find and Modify
  - 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
    
    MongoDB documentation
    
    Index Creation Tutorials
  - createIndex
```
public void createIndex(DBObject keys)
```
    Forces creation of an index on a set of fields with the default options, 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
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Index Creation Tutorials
  - createIndex
```
public void createIndex(DBObject keys,
                        DBObject options)
```
    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
    
    options - a document that controls the creation of the index.
    
    Throws:
    
    MongoException
    
    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
    
    MongoDB documentation
    
    Index Creation Tutorials
  - createIndex
```
public void createIndex(DBObject keys,
                        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
    
    MongoDB documentation
    
    Index Creation Tutorials
  - createIndex
```
@Deprecated
public abstract void createIndex(DBObject keys,
                                             DBObject options,
                                             DBEncoder encoder)
```
    Deprecated. use createIndex(DBObject, com.mongodb.DBObject) the encoder is not used.
    
    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
    
    options - a document that controls the creation of the index.
    
    encoder - specifies the encoder that used during operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Index Creation Tutorials
  - ensureIndex
```
@Deprecated
public void ensureIndex(String name)
```
    Deprecated. use createIndex(String) instead
    
    Creates an ascending index on a field with default options, if one does not already exist.
    
    Parameters:
    
    name - name of field to index on
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Index Creation Tutorials
  - ensureIndex
```
@Deprecated
public void ensureIndex(DBObject keys)
```
    Deprecated. use createIndex(DBObject) instead
    
    Calls ensureIndex(com.mongodb.DBObject, com.mongodb.DBObject) with default options
    
    Parameters:
    
    keys - an object with a key set of the fields desired for the index
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Index Creation Tutorials
  - ensureIndex
```
@Deprecated
public void ensureIndex(DBObject keys,
                                    String name)
```
    Deprecated. use createIndex(DBObject, DBObject) instead
    
    Calls ensureIndex(com.mongodb.DBObject, java.lang.String, boolean) with unique=false
    
    Parameters:
    
    keys - fields to use for index
    
    name - an identifier for the index
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Index Creation Tutorials
  - ensureIndex
```
@Deprecated
public void ensureIndex(DBObject keys,
                                    String name,
                                    boolean unique)
```
    Deprecated. use createIndex(DBObject, String, boolean) instead
    
    Ensures an index on this collection (that is, the index will be created if it does not exist).
    
    Parameters:
    
    keys - fields to use for 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
    
    MongoDB documentation
    
    Index Creation Tutorials
  - ensureIndex
```
@Deprecated
public void ensureIndex(DBObject keys,
                                    DBObject optionsIN)
```
    Deprecated. use createIndex(DBObject, DBObject) instead
    
    Creates an index on a set of fields, if one does not already exist.
    
    Parameters:
    
    keys - an object with a key set of the fields desired for the index
    
    optionsIN - options for the index (name, unique, etc)
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Index Creation Tutorials
  - resetIndexCache
```
@Deprecated
public void resetIndexCache()
```
    Deprecated. This will be removed in 3.0
    
    Clears all indices that have not yet been applied to this collection.
  - genIndexName
```
@Deprecated
public static String genIndexName(DBObject keys)
```
    Deprecated. This method is NOT a part of public API and will be dropped in 3.x versions.
    
    Convenience method to generate an index name from the set of fields it is over.
    
    Parameters:
    
    keys - the names of the fields used in this index
    
    Returns:
    
    a string representation of this index's fields
  - setHintFields
```
public void setHintFields(List<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
  - getHintFields
```
protected 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
  - find
```
public DBCursor find(DBObject ref)
```
    Queries for an object in this collection.
    
    Parameters:
    
    ref - A document outlining the search query
    
    Returns:
    
    an iterator over the results
    
    MongoDB documentation
    
    Query
  - find
```
public DBCursor find(DBObject ref,
                     DBObject keys)
```
    Queries for an object in this collection.
    An empty DBObject will match every document in the collection. Regardless of fields specified, the _id fields are always returned.
    
    An example that returns the "x" and "_id" fields for every document in the collection that has an "x" field:
```
 
 BasicDBObject keys = new BasicDBObject();
 keys.put("x", 1);

 DBCursor cursor = collection.find(new BasicDBObject(), keys);
 
```
    Parameters:
    
    ref - object for which to search
    
    keys - fields to return
    
    Returns:
    
    a cursor to iterate over results
    
    MongoDB documentation
    
    Query
  - find
```
public DBCursor find()
```
    Queries for all objects in this collection.
    
    Returns:
    
    a cursor which will iterate over every object
    
    MongoDB documentation
    
    Query
  - findOne
```
public DBObject findOne()
```
    Returns a single object from this collection.
    
    Returns:
    
    the object found, or null if the collection is empty
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - findOne
```
public DBObject findOne(DBObject o)
```
    Returns a single object from this collection matching the query.
    
    Parameters:
    
    o - the query object
    
    Returns:
    
    the object found, or null if no such object exists
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - findOne
```
public DBObject findOne(DBObject o,
                        DBObject fields)
```
    Returns a single object from this collection matching the query.
    
    Parameters:
    
    o - the query object
    
    fields - fields to return
    
    Returns:
    
    the object found, or null if no such object exists
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - findOne
```
public DBObject findOne(DBObject o,
                        DBObject fields,
                        DBObject orderBy)
```
    Returns a single object from this collection matching the query.
    
    Parameters:
    
    o - the query object
    
    fields - fields to return
    
    orderBy - fields to order by
    
    Returns:
    
    the object found, or null if no such object exists
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - findOne
```
public DBObject findOne(DBObject o,
                        DBObject fields,
                        ReadPreference readPref)
```
    Get a single document from collection.
    
    Parameters:
    
    o - the selection criteria using query operators.
    
    fields - specifies which fields MongoDB will return from the documents in the result set.
    
    readPref - ReadPreference to be used for this operation
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method, or null if no such object exists
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - findOne
```
public DBObject findOne(DBObject o,
                        DBObject fields,
                        DBObject orderBy,
                        ReadPreference readPref)
```
    Get a single document from collection.
    
    Parameters:
    
    o - the selection criteria using query operators.
    
    fields - specifies which projection MongoDB will return from the documents in the result set.
    
    orderBy - A document whose fields specify the attributes on which to sort the result set.
    
    readPref - ReadPreference to be used for this operation
    
    Returns:
    
    A document that satisfies the query specified as the argument to this method, or null if no such object exists
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Query
  - apply
```
@Deprecated
public Object apply(DBObject document)
```
    Deprecated. This method will be removed in a future release. There is no replacement.
    
    Template method pattern. Please extend DBCollection and override doapply(DBObject) if you need to add specific fields before saving object to collection.
    
    Parameters:
    
    document - document to be passed to doapply()
    
    Returns:
    
    '_id' of the document
  - apply
```
@Deprecated
public Object apply(DBObject document,
                                boolean ensureId)
```
    Deprecated. This method will be removed in a future release. There is no replacement.
    
    Template method pattern. Please extend DBCollection and override doapply(DBObject) if you need to add specific fields before saving object to collection.
    
    Parameters:
    
    document - document to be passed to doapply()
    
    ensureId - specifies if '_id' field needs to be added to the document in case of absence.
    
    Returns:
    
    '_id' of the document
  - save
```
public WriteResult save(DBObject jo)
```
    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:
    
    jo - DBObject to save to the collection.
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Save
  - save
```
public WriteResult save(DBObject jo,
                        WriteConcern concern)
```
    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:
    
    jo - DBObject to save to the collection.
    
    concern - WriteConcern to be used during operation
    
    Returns:
    
    the result of the operation
    
    Throws:
    
    MongoException - if the operation fails
    
    MongoDB documentation
    
    Save
  - dropIndexes
```
public void dropIndexes()
```
    Drop all indexes on this collection. The default index on the _id field will not be deleted.
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Indexes
  - dropIndexes
```
public void dropIndexes(String name)
```
    Drops the index with the given name from this collection. This method is exactly the same as dropIndex(indexName).
    
    Parameters:
    
    name - name of index to drop
    
    Throws:
    
    MongoException - if the index does not exist
    
    MongoDB documentation
    
    Indexes
  - drop
```
public void drop()
```
    Drops (deletes) this collection from the database. Use with care.
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Drop Command
  - count
```
public long count()
```
    Get the number of documents in the collection.
    
    Returns:
    
    the number of documents
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - count
```
public long count(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
    
    MongoDB documentation
    
    Count
  - count
```
public long count(DBObject query,
                  ReadPreference readPrefs)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - getCount
```
public long getCount()
```
    Get the count of documents in a collection. Calls getCount(com.mongodb.DBObject, com.mongodb.DBObject) with an empty query and null fields.
    
    Returns:
    
    the number of documents in the collection
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - getCount
```
public long getCount(ReadPreference readPrefs)
```
    Get the count of documents in a collection. Calls getCount(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.ReadPreference) with empty query and null fields.
    
    Parameters:
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - getCount
```
public long getCount(DBObject query)
```
    Get the count of documents in collection that would match a criteria. Calls getCount(com.mongodb.DBObject, com.mongodb.DBObject) with null fields.
    
    Parameters:
    
    query - specifies the selection criteria
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - getCount
```
public long getCount(DBObject query,
                     DBObject fields)
```
    Get the count of documents in collection that would match a criteria. Calls getCount(com.mongodb.DBObject, com.mongodb.DBObject, long, long) with limit=0 and skip=0
    
    Parameters:
    
    query - specifies the selection criteria
    
    fields - this is ignored
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - getCount
```
public long getCount(DBObject query,
                     DBObject fields,
                     ReadPreference readPrefs)
```
    Get the count of documents in collection that would match a criteria. Calls getCount(com.mongodb.DBObject, com.mongodb.DBObject, long, long, com.mongodb.ReadPreference) with limit=0 and skip=0
    
    Parameters:
    
    query - specifies the selection criteria
    
    fields - this is ignored
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - getCount
```
public long getCount(DBObject query,
                     DBObject fields,
                     long limit,
                     long skip)
```
    Get the count of documents in collection that would match a criteria. Calls getCount(com.mongodb.DBObject, com.mongodb.DBObject, long, long, com.mongodb.ReadPreference) with the DBCollection's ReadPreference
    
    Parameters:
    
    query - specifies the selection criteria
    
    fields - 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
    
    MongoDB documentation
    
    Count
  - getCount
```
public long getCount(DBObject query,
                     DBObject fields,
                     long limit,
                     long skip,
                     ReadPreference readPrefs)
```
    Get the count of documents in collection that would match a criteria.
    
    Parameters:
    
    query - specifies the selection criteria
    
    fields - this is ignored
    
    limit - limit the count to this value
    
    skip - number of documents to skip
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    the number of documents that matches selection criteria
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Count
  - rename
```
public DBCollection rename(String newName)
```
    Calls rename(java.lang.String, boolean) with dropTarget=false
    
    Parameters:
    
    newName - new collection name (not a full namespace)
    
    Returns:
    
    the new collection
    
    Throws:
    
    MongoException
  - rename
```
public DBCollection rename(String newName,
                           boolean dropTarget)
```
    Renames of this collection to newName
    
    Parameters:
    
    newName - new collection name (not a full namespace)
    
    dropTarget - if a collection with the new name exists, whether or not to drop it
    
    Returns:
    
    the new collection
    
    Throws:
    
    MongoException
  - 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. Calls group(com.mongodb.DBObject, com.mongodb.DBObject, com.mongodb.DBObject, java.lang.String, java.lang.String) with finalize=null
    
    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
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Group Command
  - group
```
public 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. 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
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Group Command
  - group
```
public DBObject group(DBObject key,
                      DBObject cond,
                      DBObject initial,
                      String reduce,
                      String finalize,
                      ReadPreference readPrefs)
```
    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
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    Throws:
    
    MongoException
    
    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 containing the details of how to perform the operation.
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Group Command
  - group
```
public DBObject group(GroupCommand cmd,
                      ReadPreference readPrefs)
```
    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 containing the details of how to perform the operation.
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Group Command
  - group
```
@Deprecated
public DBObject group(DBObject args)
```
    Deprecated. use group(com.mongodb.GroupCommand) instead. This method will be removed in 3.0
    
    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:
    
    args - object representing the arguments to the group function
    
    Returns:
    
    a document with the grouped records as well as the command meta-data
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Group Command
  - distinct
```
public List distinct(String key)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    key - Specifies the field for which to return the distinct values
    
    Returns:
    
    A List of the distinct values
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Distinct Command
  - distinct
```
public List distinct(String key,
                     ReadPreference readPrefs)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    key - Specifies the field for which to return the distinct values
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    A List of the distinct values
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Distinct Command
  - distinct
```
public List distinct(String key,
                     DBObject query)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    key - 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:
    
    A List of the distinct values
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Distinct Command
  - distinct
```
public List distinct(String key,
                     DBObject query,
                     ReadPreference readPrefs)
```
    Find the distinct values for a specified field across a collection and returns the results in an array.
    
    Parameters:
    
    key - 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
    
    readPrefs - ReadPreference to be used for this operation
    
    Returns:
    
    A List of the distinct values
    
    Throws:
    
    MongoException
    
    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. Runs the command in REPLACE output mode (saves to 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 (optional) - leave null if want to use temp collection
    
    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
    
    Throws:
    
    MongoException
    
    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. Specify an outputType to control job execution
    - INLINE - Return results inline
    - REPLACE - Replace the output collection with the job output
    - MERGE - Merge the job output with the existing contents of outputTarget
    - REDUCE - Reduce the job output with the existing contents of outputTarget
    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 (optional) - leave null if want to use temp collection
    
    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
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Map-Reduce
  - mapReduce
```
public MapReduceOutput mapReduce(String map,
                                 String reduce,
                                 String outputTarget,
                                 MapReduceCommand.OutputType outputType,
                                 DBObject query,
                                 ReadPreference readPrefs)
```
    Allows you to run map-reduce aggregation operations over a collection and saves to a named collection. Specify an outputType to control job execution
    - INLINE - Return results inline
    - REPLACE - Replace the output collection with the job output
    - MERGE - Merge the job output with the existing contents of outputTarget
    - REDUCE - Reduce the job output with the existing contents of outputTarget
    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 (optional) - leave null if want to use temp collection
    
    outputType - specifies the type of job output
    
    query - specifies the selection criteria using query operators for determining the documents input to the map function.
    
    readPrefs - 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
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Map-Reduce
  - mapReduce
```
public MapReduceOutput mapReduce(MapReduceCommand command)
```
    Allows you to run map-reduce aggregation operations over a collection and saves to a named collection.
    
    Parameters:
    
    command - object representing the parameters to the operation
    
    Returns:
    
    A MapReduceOutput which contains the results of this map reduce operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Map-Reduce
  - mapReduce
```
@Deprecated
public MapReduceOutput mapReduce(DBObject command)
```
    Deprecated. Use mapReduce(MapReduceCommand) instead
    
    Allows you to run map-reduce aggregation operations over a collection
    
    Parameters:
    
    command - document representing the parameters to this operation.
    
    Returns:
    
    A MapReduceOutput which contains the results of this map reduce operation
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Map-Reduce
  - aggregate
```
@Deprecated
public AggregationOutput aggregate(DBObject firstOp,
                                               DBObject... additionalOps)
```
    Deprecated. Use aggregate(java.util.List) 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
```
public AggregationOutput aggregate(List<DBObject> pipeline)
```
    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
```
public AggregationOutput aggregate(List<DBObject> pipeline,
                                   ReadPreference readPreference)
```
    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<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 abstract Cursor aggregate(List<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<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 abstract 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
  - 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()
  - getIndexInfo
```
public abstract 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
  - dropIndex
```
public void dropIndex(DBObject keys)
```
    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:
    
    keys - 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
  - 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
    
    Throws:
    
    MongoException
    
    MongoDB documentation
    
    Capped Collections
  - _checkObject
```
@Deprecated
protected DBObject _checkObject(DBObject o,
                                            boolean canBeNull,
                                            boolean query)
```
    Deprecated. This method should not be a part of API. If you override one of the DBCollection methods please rely on superclass implementation in checking argument correctness and validity.
  - getCollection
```
public DBCollection getCollection(String n)
```
    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:
    
    n - the name of the collection to find
    
    Returns:
    
    the matching collection
  - 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
  - getDB
```
public DB getDB()
```
    Returns the database this collection is a member of.
    
    Returns:
    
    this collection's database
    
    MongoDB documentation
    
    Database
  - checkReadOnly
```
@Deprecated
protected boolean checkReadOnly(boolean strict)
```
    Deprecated. See DB.setReadOnly(Boolean)
    
    Returns if this collection's database is read-only
    
    Parameters:
    
    strict - if an exception should be thrown if the database is read-only
    
    Returns:
    
    if this collection's database is read-only
    
    Throws:
    
    RuntimeException - if the database is read-only and strict is set
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - setObjectClass
```
public void setObjectClass(Class c)
```
    Sets a default class for objects in this collection; null resets the class to nothing.
    
    Parameters:
    
    c - the class
    
    Throws:
    
    IllegalArgumentException - if c is not a DBObject
  - getObjectClass
```
public Class getObjectClass()
```
    Gets the default class for objects in the collection
    
    Returns:
    
    the class
  - setInternalClass
```
public void setInternalClass(String path,
                             Class c)
```
    Sets the internal class for the given path in the document hierarchy
    
    Parameters:
    
    path - the path to map the given Class to
    
    c - the Class to map the given path to
  - getInternalClass
```
protected Class 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
  - 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
  - getWriteConcern
```
public WriteConcern getWriteConcern()
```
    Get the WriteConcern for this collection.
    
    Returns:
    
    the default write concern for this collection
    
    MongoDB documentation
    
    Write Concern
  - 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
  - getReadPreference
```
public ReadPreference getReadPreference()
```
    Gets the ReadPreference.
    
    Returns:
    
    the default read preference for this collection
    
    MongoDB documentation
    
    Read Preference
  - 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
  - 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
  - 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
  - setDBDecoderFactory
```
public void setDBDecoderFactory(DBDecoderFactory fact)
```
    Set a customer decoder factory for this collection. Set to null to use the default from MongoOptions.
    
    Parameters:
    
    fact - the factory to set.
  - 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
  - setDBEncoderFactory
```
public void setDBEncoderFactory(DBEncoderFactory fact)
```
    Set a customer encoder factory for this collection. Set to null to use the default from MongoOptions.
    
    Parameters:
    
    fact - 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

Class DBCollection

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

_name

_fullName

_hintFields

_objectClass

Constructor Detail

DBCollection

Method Detail

insert

insert

insert

insert

insert

insert

insert

insert

insert

update

update

update

update

updateMulti

doapply

remove

remove

remove

find

find

findOne

findOne

findAndModify

findAndModify

findAndModify

findAndModify

findAndRemove

createIndex

createIndex

createIndex

createIndex

createIndex

createIndex

ensureIndex

ensureIndex

ensureIndex

ensureIndex

ensureIndex

resetIndexCache

genIndexName

setHintFields

getHintFields

find

find

find

findOne

findOne

findOne

findOne

findOne

findOne

apply

apply

save

save

dropIndexes

dropIndexes

drop

count

count

count

getCount

getCount

getCount

getCount

getCount

getCount