com.mongodb

Class Mongo

java.lang.Object

com.mongodb.Mongo

Direct Known Subclasses:

MongoClient

public class Mongo
extends Object

A database connection with internal connection pooling. For most applications, you should have one Mongo instance for the entire JVM.

The following are equivalent, and all connect to the local database running on the default port:

 Mongo mongo1 = new Mongo();
 Mongo mongo1 = new Mongo("localhost");
 Mongo mongo2 = new Mongo("localhost", 27017);
 Mongo mongo4 = new Mongo(new ServerAddress("localhost"));
 

You can connect to a replica set using the Java driver by passing a ServerAddress list to the Mongo constructor. For example:

 Mongo mongo = new Mongo(Arrays.asList(
   new ServerAddress("localhost", 27017),
   new ServerAddress("localhost", 27018),
   new ServerAddress("localhost", 27019)));
 

You can connect to a sharded cluster using the same constructor. Mongo will auto-detect whether the servers are a list of replica set members or a list of mongos servers.

By default, all read and write operations will be made on the primary, but it's possible to read from secondaries by changing the read preference:

 mongo.setReadPreference(ReadPreference.secondary());
 

By default, write operations will not throw exceptions on failure, but that is easily changed too:

 mongo.setWriteConcern(WriteConcern.SAFE);
 

Note: This class has been superseded by MongoClient, and may be deprecated in a future release.

See Also:

MongoClient, ReadPreference, WriteConcern

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Mongo.Holder Mongo.Holder can be used as a static place to hold several instances of Mongo.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAJOR_VERSION Deprecated. Replaced by getMajorVersion()
static int	MINOR_VERSION Deprecated. Replaced by getMinorVersion()

Constructor Summary

Constructors

Constructor and Description
Mongo() Deprecated. Replaced by MongoClient.MongoClient())
Mongo(List<ServerAddress> seeds) Deprecated. Replaced by MongoClient.MongoClient(java.util.List)
Mongo(List<ServerAddress> seeds, MongoOptions options) Deprecated. Replaced by MongoClient.MongoClient(java.util.List, MongoClientOptions)
Mongo(MongoURI uri) Deprecated. Replaced by MongoClient.MongoClient(MongoClientURI)
Mongo(ServerAddress addr) Deprecated. Replaced by MongoClient.MongoClient(ServerAddress)
Mongo(ServerAddress addr, MongoOptions options) Deprecated. Replaced by MongoClient.MongoClient(ServerAddress, MongoClientOptions)
Mongo(ServerAddress left, ServerAddress right) Deprecated.
Mongo(ServerAddress left, ServerAddress right, MongoOptions options) Deprecated. Please use MongoClient.MongoClient(java.util.List, MongoClientOptions) instead.
Mongo(String host) Deprecated. Replaced by MongoClient.MongoClient(String)
Mongo(String host, int port) Deprecated. Replaced by MongoClient.MongoClient(String, int)
Mongo(String host, MongoOptions options) Deprecated. Replaced by MongoClient.MongoClient(String, MongoClientOptions)

Method Summary

Modifier and Type	Method and Description
void	addOption(int option) Add a default query option keeping any previously added options.
void	close() Closes the underlying connector, which in turn closes all open connections.
static DB	connect(DBAddress addr) Deprecated. Please use getDB(String) instead.
String	debugString() Deprecated. This method is NOT a part of public API and will be dropped in 3.x versions.
void	dropDatabase(String dbName) Drops the database if it exists.
CommandResult	fsync(boolean async) Forces the master server to fsync the RAM data to disk This is done automatically by the server at intervals, but can be forced for better reliability.
CommandResult	fsyncAndLock() Forces the master server to fsync the RAM data to disk, then lock all writes.
ServerAddress	getAddress() Gets the address of the current master
List<ServerAddress>	getAllAddress() Gets a list of all server addresses used when this Mongo was created
DBTCPConnector	getConnector() Deprecated. DBTCPConnector is NOT part of the public API. It will be dropped in 3.x releases.
String	getConnectPoint() Gets a String representation of current connection point, i.e.
List<String>	getDatabaseNames() Gets a list of the names of all databases on the connected server.
DB	getDB(String dbname) Gets a database object from this MongoDB instance.
static int	getMajorVersion() Deprecated. Please use getVersion() instead.
int	getMaxBsonObjectSize() Gets the maximum size for a BSON object supported by the current master server.
static int	getMinorVersion() Deprecated. Please use getVersion() instead.
MongoOptions	getMongoOptions() Deprecated. Please use MongoClient and corresponding MongoClient.getMongoClientOptions()
int	getOptions() Gets the default query options
ReadPreference	getReadPreference() Gets the default read preference
ReplicaSetStatus	getReplicaSetStatus() Get the status of the replica set cluster.
List<ServerAddress>	getServerAddressList() Gets the list of server addresses currently seen by this client.
Collection<DB>	getUsedDatabases() Returns the list of databases used by the driver since this Mongo instance was created.
String	getVersion() Deprecated. There is no replacement for this method.
WriteConcern	getWriteConcern() Gets the default write concern
boolean	isLocked() Returns true if the database is locked (read-only), false otherwise.
void	resetOptions() Reset the default query options
void	setOptions(int options) Set the default query options.
void	setReadPreference(ReadPreference preference) Sets the read preference for this database.
void	setWriteConcern(WriteConcern concern) Sets the write concern for this database.
void	slaveOk() Deprecated. Replaced with ReadPreference.secondaryPreferred()
String	toString()
DBObject	unlock() Unlocks the database, allowing the write operations to go through.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

MAJOR_VERSION

@Deprecated
public static final int MAJOR_VERSION

Deprecated. Replaced by getMajorVersion()

See Also:

Constant Field Values

MINOR_VERSION

@Deprecated
public static final int MINOR_VERSION

Deprecated. Replaced by getMinorVersion()

See Also:

Constant Field Values

Constructor Detail

Mongo

@Deprecated
public Mongo()
                  throws UnknownHostException

Deprecated. Replaced by MongoClient.MongoClient())

Creates a Mongo instance based on a (single) mongodb node (localhost, default port)

Throws:

UnknownHostException - This exception is no longer thrown, but leaving in throws clause so as not to break source compatibility. The exception will be removed from the declaration in the next major release of the driver.

Mongo

@Deprecated
public Mongo(String host)
                  throws UnknownHostException

Deprecated. Replaced by MongoClient.MongoClient(String)

Creates a Mongo instance based on a (single) mongodb node (default port)

Parameters:

host - server to connect to

Throws:

UnknownHostException - This exception is no longer thrown, but leaving in throws clause so as not to break source compatibility. The exception will be removed from the declaration in the next major release of the driver.

Mongo

@Deprecated
public Mongo(String host,
                         MongoOptions options)
                  throws UnknownHostException

Deprecated. Replaced by MongoClient.MongoClient(String, MongoClientOptions)

Creates a Mongo instance based on a (single) mongodb node (default port)

Parameters:

host - server to connect to

options - default query options

Throws:

UnknownHostException - This exception is no longer thrown, but leaving in throws clause so as not to break source compatibility. The exception will be removed from the declaration in the next major release of the driver.

Mongo

@Deprecated
public Mongo(String host,
                         int port)
                  throws UnknownHostException

Deprecated. Replaced by MongoClient.MongoClient(String, int)

Creates a Mongo instance based on a (single) mongodb node

Parameters:

host - the database's host address

port - the port on which the database is running

Throws:

UnknownHostException - This exception is no longer thrown, but leaving in throws clause so as not to break source compatibility. The exception will be removed from the declaration in the next major release of the driver.

Mongo

@Deprecated
public Mongo(ServerAddress addr)

Deprecated. Replaced by MongoClient.MongoClient(ServerAddress)

Creates a Mongo instance based on a (single) mongodb node

Parameters:

addr - the database address

See Also:

ServerAddress

Mongo

@Deprecated
public Mongo(ServerAddress addr,
                         MongoOptions options)

Deprecated. Replaced by MongoClient.MongoClient(ServerAddress, MongoClientOptions)

Creates a Mongo instance based on a (single) mongo node using a given ServerAddress

Parameters:

addr - the database address

options - default query options

See Also:

ServerAddress

Mongo

@Deprecated
public Mongo(ServerAddress left,
                         ServerAddress right)

Deprecated.

Creates a Mongo in paired mode. This will also work for a replica set and will find all members (the master will be used by default).

Parameters:

left - left side of the pair

right - right side of the pair

Throws:

MongoException

Mongo

@Deprecated
public Mongo(ServerAddress left,
                         ServerAddress right,
                         MongoOptions options)

Deprecated. Please use MongoClient.MongoClient(java.util.List, MongoClientOptions) instead.

Creates a Mongo connection in paired mode. This will also work for a replica set and will find all members (the master will be used by default).

Parameters:

left - left side of the pair

right - right side of the pair

options - the optional settings for the Mongo instance

See Also:

ServerAddress

Mongo

@Deprecated
public Mongo(List<ServerAddress> seeds)

Deprecated. Replaced by MongoClient.MongoClient(java.util.List)

Creates a Mongo based on a list of replica set members or a list of mongos. It will find all members (the master will be used by default). If you pass in a single server in the list, the driver will still function as if it is a replica set. If you have a standalone server, use the Mongo(ServerAddress) constructor.

If this is a list of mongos servers, it will pick the closest (lowest ping time) one to send all requests to, and automatically fail over to the next server if the closest is down.

Parameters:

seeds - Put as many servers as you can in the list and the system will figure out the rest. This can either be a list of mongod servers in the same replica set or a list of mongos servers in the same sharded cluster.

See Also:

ServerAddress

Mongo

@Deprecated
public Mongo(List<ServerAddress> seeds,
                         MongoOptions options)

Deprecated. Replaced by MongoClient.MongoClient(java.util.List, MongoClientOptions)

Creates a Mongo based on a list of replica set members or a list of mongos. It will find all members (the master will be used by default). If you pass in a single server in the list, the driver will still function as if it is a replica set. If you have a standalone server, use the Mongo(ServerAddress) constructor.

If this is a list of mongos servers, it will pick the closest (lowest ping time) one to send all requests to, and automatically fail over to the next server if the closest is down.

Parameters:

seeds - Put as many servers as you can in the list and the system will figure out the rest. This can either be a list of mongod servers in the same replica set or a list of mongos servers in the same sharded cluster.

options - for configuring this Mongo instance

See Also:

ServerAddress

Mongo

@Deprecated
public Mongo(MongoURI uri)
                  throws UnknownHostException

Deprecated. Replaced by MongoClient.MongoClient(MongoClientURI)

Creates a Mongo described by a URI. If only one address is used it will only connect to that node, otherwise it will discover all nodes. If the URI contains database credentials, the database will be authenticated lazily on first use with those credentials.

Examples:

• mongodb://localhost
• mongodb://fred:foobar@localhost/

Parameters:

uri - URI to connect to, optionally containing additional information like credentials

Throws:

UnknownHostException

See Also:

MongoURI

MongoDB documentation

Connection String URI Format

Method Detail

getMajorVersion

@Deprecated
public static int getMajorVersion()

Deprecated. Please use getVersion() instead.

Gets the major version of this library

Returns:

the major version, e.g. 2

getMinorVersion

@Deprecated
public static int getMinorVersion()

Deprecated. Please use getVersion() instead.

Gets the minor version of this library

Returns:

the minor version, e.g. 8

connect

@Deprecated
public static DB connect(DBAddress addr)

Deprecated. Please use getDB(String) instead.

Connect to the MongoDB instance at the given address, select and return the DB specified in the DBAddress parameter.

Parameters:

addr - The details of the server and database to connect to

Returns:

the DB requested in the addr parameter.

Throws:

MongoException

getDB

public DB getDB(String dbname)

Gets a database object from this MongoDB instance.

Parameters:

dbname - the name of the database to retrieve

Returns:

a DB representing the specified database

getUsedDatabases

public Collection<DB> getUsedDatabases()

Returns the list of databases used by the driver since this Mongo instance was created. This may include DBs that exist in the client but not yet on the server.

Returns:

a collection of database objects

getDatabaseNames

public List<String> getDatabaseNames()

Gets a list of the names of all databases on the connected server.

Returns:

list of database names

Throws:

MongoException

dropDatabase

public void dropDatabase(String dbName)

Drops the database if it exists.

Parameters:

dbName - name of database to drop

Throws:

MongoException

getVersion

@Deprecated
public String getVersion()

Deprecated. There is no replacement for this method.

Gets this driver version.

Returns:

the full version string of this driver, e.g. "2.8.0"

debugString

@Deprecated
public String debugString()

Deprecated. This method is NOT a part of public API and will be dropped in 3.x versions.

Get a String for debug purposes.

Returns:

a string representing the hosts used in this Mongo instance

getConnectPoint

public String getConnectPoint()

Gets a String representation of current connection point, i.e. master.

Returns:

server address in a host:port form

getConnector

@Deprecated
public DBTCPConnector getConnector()

Deprecated. DBTCPConnector is NOT part of the public API. It will be dropped in 3.x releases.

Gets the underlying TCP connector

Returns:

A DBTCPConnector representing the connection to MongoDB

getReplicaSetStatus

public ReplicaSetStatus getReplicaSetStatus()

Get the status of the replica set cluster.

Returns:

replica set status information

getAddress

public ServerAddress getAddress()

Gets the address of the current master

Returns:

the address

getAllAddress

public List<ServerAddress> getAllAddress()

Gets a list of all server addresses used when this Mongo was created

Returns:

list of server addresses

Throws:

MongoException

getServerAddressList

public List<ServerAddress> getServerAddressList()

Gets the list of server addresses currently seen by this client. This includes addresses auto-discovered from a replica set.

Returns:

list of server addresses

Throws:

MongoException

close

public void close()

Closes the underlying connector, which in turn closes all open connections. Once called, this Mongo instance can no longer be used.

setWriteConcern

public void setWriteConcern(WriteConcern concern)

Sets the write concern for this database. Will be used as default for writes to any collection in any database. See the documentation for WriteConcern for more information.

Parameters:

concern - write concern to use

getWriteConcern

public WriteConcern getWriteConcern()

Gets the default write concern

Returns:

the default write concern

setReadPreference

public void setReadPreference(ReadPreference preference)

Sets the read preference for this database. Will be used as default for reads from any collection in any database. See the documentation for ReadPreference for more information.

Parameters:

preference - Read Preference to use

getReadPreference

public ReadPreference getReadPreference()

Gets the default read preference

Returns:

the default read preference

slaveOk

@Deprecated
public void slaveOk()

Deprecated. Replaced with ReadPreference.secondaryPreferred()

Makes it possible to run read queries on secondary nodes

See Also:

ReadPreference.secondaryPreferred()

addOption

public void addOption(int option)

Add a default query option keeping any previously added options.

Parameters:

option - value to be added to current options

setOptions

public void setOptions(int options)

Set the default query options. Overrides any existing options.

Parameters:

options - value to be set

resetOptions

public void resetOptions()

Reset the default query options

getOptions

public int getOptions()

Gets the default query options

Returns:

an int representing the options to be used by queries

getMongoOptions

@Deprecated
public MongoOptions getMongoOptions()

Deprecated. Please use MongoClient and corresponding MongoClient.getMongoClientOptions()

Returns the mongo options.

Returns:

A MongoOptions containing the settings for this MongoDB instance.

getMaxBsonObjectSize

public int getMaxBsonObjectSize()

Gets the maximum size for a BSON object supported by the current master server. Note that this value may change over time depending on which server is master.

Returns:

the maximum size, or 0 if not obtained from servers yet.

Throws:

MongoException

fsync

public CommandResult fsync(boolean async)

Forces the master server to fsync the RAM data to disk This is done automatically by the server at intervals, but can be forced for better reliability.

Parameters:

async - if true, the fsync will be done asynchronously on the server.

Returns:

result of the command execution

Throws:

MongoException

MongoDB documentation

fsync command

fsyncAndLock

public CommandResult fsyncAndLock()

Forces the master server to fsync the RAM data to disk, then lock all writes. The database will be read-only after this command returns.

Returns:

result of the command execution

Throws:

MongoException

MongoDB documentation

fsync command

unlock

public DBObject unlock()

Unlocks the database, allowing the write operations to go through. This command may be asynchronous on the server, which means there may be a small delay before the database becomes writable.

Returns:

DBObject in the following form {"ok": 1,"info": "unlock completed"}

Throws:

MongoException

MongoDB documentation

fsync command

isLocked

public boolean isLocked()

Returns true if the database is locked (read-only), false otherwise.

Returns:

result of the command execution

Throws:

MongoException

MongoDB documentation

fsync command

toString

public String toString()

Overrides:

toString in class Object