Package com.mongodb

Class MongoClient

  • All Implemented Interfaces:
    Closeable, AutoCloseable

    public class MongoClient
    extends Object
    implements Closeable

    A MongoDB client with internal connection pooling. For most applications, you should have one MongoClient instance for the entire JVM.

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

     new MongoClient()
     new MongoClient("mongodb://localhost")
     new MongoClient("mongodb://localhost:27017");
     new MongoClient(MongoClientSettings.builder()
       .applyConnectionString("mongodb://localhost")
       .build())
     

    You can connect to a replica set by passing a list of servers to a MongoClient constructor. For example:

     new MongoClient("mongodb://localhost:27017,localhost:27018,localhost:27019")
     new MongoClient(MongoClientSettings.builder()
       .applyConnectionString("mongodb://localhost:27017,localhost:27018,localhost:27019")
       .build())
     

    You can connect to a sharded cluster using the same constructor invocations. MongoClient 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:

     new MongoClient("mongodb://localhost:27017,localhost:27018,localhost:27019?readPreference=primary")
     new MongoClient(MongoClientSettings.builder()
       .applyConnectionString("mongodb://localhost:27017,localhost:27018,localhost:27019/?readPreference=primary")
       .build())
     new MongoClient(MongoClientSettings.builder()
       .applyConnectionString("mongodb://localhost:27017,localhost:27018,localhost:27019")
       .readPreference(ReadPreference.primary())
       .build())
     

    By default, all write operations will wait for acknowledgment by the server, as the default write concern is WriteConcern.ACKNOWLEDGED. It's possible to change this with a setting:

     new MongoClient("mongodb://localhost:27017,localhost:27018,localhost:27019?w=majority")
     new MongoClient(MongoClientSettings.builder()
       .applyConnectionString("mongodb://localhost:27017,localhost:27018,localhost:27019/?w=majority")
       .build())
     new MongoClient(MongoClientSettings.builder()
       .applyConnectionString("mongodb://localhost:27017,localhost:27018,localhost:27019")
       .writeConcern(WriteConcern.MAJORITY)
       .build())
     

    In general, users of this class will pick up all of the default options specified in MongoClientSettings.

    Since:
    2.10.0
    See Also:
    ConnectionString, MongoClientSettings
    • Constructor Detail

      • MongoClient

        public MongoClient()
        Creates an instance based on a (single) MongoDB server ("mongodb://127.0.0.1:27017").
      • MongoClient

        public MongoClient​(String connectionString)
        Creates a MongoClient instance based on a connection string.
        Parameters:
        connectionString - server to connect to in connection string format. For backwards compatibility, the "mongodb://" prefix can be omitted
        See Also:
        ConnectionString
      • MongoClient

        public MongoClient​(ConnectionString connectionString,
                           @Nullable
                           MongoDriverInformation mongoDriverInformation)
        Create a new client with the given connection string.

        For each of the settings classed configurable via MongoClientSettings, the connection string is applied by calling the applyConnectionString method on an instance of setting's builder class, building the setting, and adding it to an instance of MongoClientSettings.Builder.

        Note: Intended for driver and library authors to associate extra driver metadata with the connections.

        Parameters:
        connectionString - the settings
        mongoDriverInformation - any driver information to associate with the MongoClient
        Since:
        4.2
      • MongoClient

        public MongoClient​(MongoClientSettings settings)
        Create a new client with the given client settings.
        Parameters:
        settings - the settings
        Since:
        4.2
      • MongoClient

        public MongoClient​(MongoClientSettings settings,
                           @Nullable
                           MongoDriverInformation mongoDriverInformation)
        Creates a new client with the given client settings.

        Note: Intended for driver and library authors to associate extra driver metadata with the connections.

        Parameters:
        settings - the settings
        mongoDriverInformation - any driver information to associate with the MongoClient
        Since:
        4.2
      • MongoClient

        public MongoClient​(String host,
                           MongoClientOptions options)
        Creates an instance based on a (single) mongodb node (default port).
        Parameters:
        host - server to connect to in format host[:port]
        options - default query options
      • MongoClient

        public MongoClient​(String host,
                           int port)
        Creates an instance based on a (single) mongodb node.
        Parameters:
        host - the database's host address
        port - the port on which the database is running
      • MongoClient

        public MongoClient​(ServerAddress addr)
        Creates an instance based on a (single) mongodb node
        Parameters:
        addr - the database address
        See Also:
        ServerAddress
      • MongoClient

        public MongoClient​(ServerAddress addr,
                           MongoClientOptions options)
        Creates an instance based on a (single) mongo node using a given ServerAddress and default options.
        Parameters:
        addr - the database address
        options - default options
        See Also:
        ServerAddress
      • MongoClient

        public MongoClient​(ServerAddress addr,
                           @Nullable
                           MongoCredential credential,
                           MongoClientOptions options)
        Creates an instance based on a (single) mongo node using a given server address, credential, and options
        Parameters:
        addr - the database address
        credential - the credential used to authenticate all connections
        options - default options
        Since:
        3.6
        See Also:
        ServerAddress
      • MongoClient

        public MongoClient​(List<ServerAddress> seeds)

        Creates an instance based on a list of replica set members or mongos servers. For a replica set it will discover all members. For a list with a single seed, the driver will still discover all members of the replica set. For a direct connection to a replica set member, with no discovery, use the MongoClient(ServerAddress) constructor instead.

        When there is more than one server to choose from based on the type of request (read or write) and the read preference (if it's a read request), the driver will randomly select a server to send a request. This applies to both replica sets and sharded clusters. The servers to randomly select from are further limited by the local threshold. See MongoClientOptions.getLocalThreshold()

        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:
        MongoClientOptions.getLocalThreshold()
      • MongoClient

        public MongoClient​(List<ServerAddress> seeds,
                           MongoClientOptions options)

        Construct an instance based on a list of replica set members or mongos servers. For a replica set it will discover all members. For a list with a single seed, the driver will still discover all members of the replica set. For a direct connection to a replica set member, with no discovery, use the MongoClient(ServerAddress, MongoClientOptions) constructor instead.

        When there is more than one server to choose from based on the type of request (read or write) and the read preference (if it's a read request), the driver will randomly select a server to send a request. This applies to both replica sets and sharded clusters. The servers to randomly select from are further limited by the local threshold. See MongoClientOptions.getLocalThreshold()

        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 - the options
        See Also:
        MongoClientOptions.getLocalThreshold()
      • MongoClient

        public MongoClient​(List<ServerAddress> seeds,
                           @Nullable
                           MongoCredential credential,
                           MongoClientOptions options)

        Creates an instance based on a list of replica set members or mongos servers. For a replica set it will discover all members. For a list with a single seed, the driver will still discover all members of the replica set. For a direct connection to a replica set member, with no discovery, use the MongoClient(ServerAddress, MongoCredential, MongoClientOptions) constructor instead.

        When there is more than one server to choose from based on the type of request (read or write) and the read preference (if it's a read request), the driver will randomly select a server to send a request. This applies to both replica sets and sharded clusters. The servers to randomly select from are further limited by the local threshold. See MongoClientOptions.getLocalThreshold()

        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.
        credential - the credential used to authenticate all connections
        options - the options
        Since:
        3.6
        See Also:
        MongoClientOptions.getLocalThreshold()
      • MongoClient

        public MongoClient​(MongoClientURI uri)
        Creates an instance described by a URI. If only one address is used it will only connect to that node, otherwise it will discover all nodes.
        Parameters:
        uri - the URI
        Throws:
        MongoException - if theres a failure
      • MongoClient

        public MongoClient​(MongoClientURI uri,
                           @Nullable
                           MongoDriverInformation mongoDriverInformation)
        Creates an instance described by a URI.

        Note: Intended for driver and library authors to associate extra driver metadata with the connections.

        Parameters:
        uri - the URI
        mongoDriverInformation - any driver information to associate with the MongoClient
        Throws:
        MongoException - if theres a failure
        Since:
        3.4
      • MongoClient

        public MongoClient​(ServerAddress addr,
                           @Nullable
                           MongoCredential credential,
                           MongoClientOptions options,
                           @Nullable
                           MongoDriverInformation mongoDriverInformation)
        Creates a MongoClient to a single node using a given ServerAddress.

        Note: Intended for driver and library authors to associate extra driver metadata with the connections.

        Parameters:
        addr - the database address
        credential - the credential used to authenticate all connections
        options - default options
        mongoDriverInformation - any driver information to associate with the MongoClient
        Since:
        3.6
        See Also:
        ServerAddress
      • MongoClient

        public MongoClient​(List<ServerAddress> seeds,
                           @Nullable
                           MongoCredential credential,
                           MongoClientOptions options,
                           @Nullable
                           MongoDriverInformation mongoDriverInformation)
        Creates a MongoClient

        Note: Intended for driver and library authors to associate extra driver metadata with the connections.

        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.
        credential - the credential used to authenticate all connections
        options - the options
        mongoDriverInformation - any driver information to associate with the MongoClient
        Since:
        3.6
    • Method Detail

      • getMongoClientOptions

        public MongoClientOptions getMongoClientOptions()
        Gets the options that this client uses to connect to server.

        Note: MongoClientOptions is immutable.

        Returns:
        the options
      • getCredential

        @Nullable
        public MongoCredential getCredential()
        Gets the credential that this client authenticates all connections with
        Returns:
        the credential, which may be null in unsecured deployments
        Since:
        3.9
      • listDatabaseNames

        public MongoIterable<String> listDatabaseNames()
        Get a list of the database names
        Returns:
        an iterable containing all the names of all the databases
        Since:
        3.0
        MongoDB documentation
        List Databases
      • listDatabaseNames

        public MongoIterable<String> listDatabaseNames​(ClientSession clientSession)
        Get a list of the database names
        Parameters:
        clientSession - the client session with which to associate this operation
        Returns:
        an iterable containing all the names of all the databases
        Since:
        3.6
        MongoDB documentation
        List Databases
        Since server release
        3.6
      • listDatabases

        public <T> ListDatabasesIterable<T> listDatabases​(Class<T> clazz)
        Gets the list of databases
        Type Parameters:
        T - the type of the class to use instead of Document.
        Parameters:
        clazz - the class to cast the database documents to
        Returns:
        the list of databases
        Since:
        3.0
      • listDatabases

        public ListDatabasesIterable<Document> listDatabases​(ClientSession clientSession)
        Gets the list of databases
        Parameters:
        clientSession - the client session with which to associate this operation
        Returns:
        the list of databases
        Since:
        3.6
        Since server release
        3.6
      • listDatabases

        public <T> ListDatabasesIterable<T> listDatabases​(ClientSession clientSession,
                                                          Class<T> clazz)
        Gets the list of databases
        Type Parameters:
        T - the type of the class to use instead of Document.
        Parameters:
        clientSession - the client session with which to associate this operation
        clazz - the class to cast the database documents to
        Returns:
        the list of databases
        Since:
        3.6
        Since server release
        3.6
      • startSession

        public ClientSession startSession()
        Creates a client session with default session options.
        Returns:
        the client session
        Throws:
        MongoClientException - if the MongoDB cluster to which this client is connected does not support sessions
        Since:
        3.8
        Since server release
        3.6
      • startSession

        public ClientSession startSession​(ClientSessionOptions options)
        Creates a client session.
        Parameters:
        options - the options for the client session
        Returns:
        the client session
        Throws:
        MongoClientException - if the MongoDB cluster to which this client is connected does not support sessions
        Since:
        3.6
        Since server release
        3.6
      • watch

        public <TResult> ChangeStreamIterable<TResult> watch​(Class<TResult> resultClass)
        Creates a change stream for this client.
        Type Parameters:
        TResult - the target document type of the iterable.
        Parameters:
        resultClass - the class to decode each document into
        Returns:
        the change stream iterable
        Since:
        3.8
        MongoDB documentation
        Change Streams
        Since server release
        4.0
      • watch

        public ChangeStreamIterable<Document> watch​(List<? extends Bson> pipeline)
        Creates a change stream for this client.
        Parameters:
        pipeline - the aggregation pipeline to apply to the change stream
        Returns:
        the change stream iterable
        Since:
        3.8
        MongoDB documentation
        Change Streams
        Since server release
        4.0
      • watch

        public <TResult> ChangeStreamIterable<TResult> watch​(List<? extends Bson> pipeline,
                                                             Class<TResult> resultClass)
        Creates a change stream for this client.
        Type Parameters:
        TResult - the target document type of the iterable.
        Parameters:
        pipeline - the aggregation pipeline to apply to the change stream
        resultClass - the class to decode each document into
        Returns:
        the change stream iterable
        Since:
        3.8
        MongoDB documentation
        Change Streams
        Since server release
        4.0
      • watch

        public ChangeStreamIterable<Document> watch​(ClientSession clientSession)
        Creates a change stream for this client.
        Parameters:
        clientSession - the client session with which to associate this operation
        Returns:
        the change stream iterable
        Since:
        3.8
        MongoDB documentation
        Change Streams
        Since server release
        4.0
      • watch

        public <TResult> ChangeStreamIterable<TResult> watch​(ClientSession clientSession,
                                                             Class<TResult> resultClass)
        Creates a change stream for this client.
        Type Parameters:
        TResult - the target document type of the iterable.
        Parameters:
        clientSession - the client session with which to associate this operation
        resultClass - the class to decode each document into
        Returns:
        the change stream iterable
        Since:
        3.8
        MongoDB documentation
        Change Streams
        Since server release
        4.0
      • watch

        public ChangeStreamIterable<Document> watch​(ClientSession clientSession,
                                                    List<? extends Bson> pipeline)
        Creates a change stream for this client.
        Parameters:
        clientSession - the client session with which to associate this operation
        pipeline - the aggregation pipeline to apply to the change stream
        Returns:
        the change stream iterable
        Since:
        3.8
        MongoDB documentation
        Change Streams
        Since server release
        4.0
      • watch

        public <TResult> ChangeStreamIterable<TResult> watch​(ClientSession clientSession,
                                                             List<? extends Bson> pipeline,
                                                             Class<TResult> resultClass)
        Creates a change stream for this client.
        Type Parameters:
        TResult - the target document type of the iterable.
        Parameters:
        clientSession - the client session with which to associate this operation
        pipeline - the aggregation pipeline to apply to the change stream
        resultClass - the class to decode each document into
        Returns:
        the change stream iterable
        Since:
        3.8
        MongoDB documentation
        Change Streams
        Since server release
        4.0
      • getWriteConcern

        public WriteConcern getWriteConcern()
        Gets the write concern
        Returns:
        the write concern
      • getReadConcern

        public ReadConcern getReadConcern()
        Gets the read concern
        Returns:
        the read concern
      • getReadPreference

        public ReadPreference getReadPreference()
        Gets the default read preference
        Returns:
        the default read preference
      • dropDatabase

        public void dropDatabase​(String dbName)
        Drops the database if it exists.
        Parameters:
        dbName - name of database to drop
        Throws:
        MongoException - if the operation fails
      • close

        public void close()
        Closes all resources associated with this instance, in particular any open network connections. Once called, this instance and any databases obtained from it can no longer be used.
        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface Closeable