org.bson.codecs

Class DocumentCodec

java.lang.Object

org.bson.codecs.DocumentCodec

All Implemented Interfaces:

Codec<Document>, CollectibleCodec<Document>, Decoder<Document>, Encoder<Document>

public class DocumentCodec
extends Object
implements CollectibleCodec<Document>

A Codec for Document instances.

Since:

3.0

See Also:

Document

Constructor Summary

Constructors

Constructor and Description
DocumentCodec() Construct a new instance with a default CodecRegistry.
DocumentCodec(CodecRegistry registry) Construct a new instance with the given registry.
DocumentCodec(CodecRegistry registry, BsonTypeClassMap bsonTypeClassMap) Construct a new instance with the given registry and BSON type class map.
DocumentCodec(CodecRegistry registry, BsonTypeClassMap bsonTypeClassMap, Transformer valueTransformer) Construct a new instance with the given registry and BSON type class map.

Method Summary

Modifier and Type	Method and Description
Document	decode(BsonReader reader, DecoderContext decoderContext) Decodes a BSON value from the given reader into an instance of the type parameter T.
boolean	documentHasId(Document document) Returns true if the given document has an _id.
void	encode(BsonWriter writer, Document document, EncoderContext encoderContext) Encode an instance of the type parameter T into a BSON value.
Document	generateIdIfAbsentFromDocument(Document document) Generates a value for the _id field on the given document, if the document does not have one.
BsonValue	getDocumentId(Document document) Gets the _id of the given document if it contains one, otherwise throws IllegalArgumentException.
Class<Document>	getEncoderClass() Returns the Class instance that this encodes.

Methods inherited from class java.lang.Object

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

Constructor Detail

DocumentCodec

public DocumentCodec()

Construct a new instance with a default CodecRegistry.

DocumentCodec

public DocumentCodec(CodecRegistry registry)

Construct a new instance with the given registry.

Parameters:

registry - the registry

Since:

3.5

DocumentCodec

public DocumentCodec(CodecRegistry registry,
                     BsonTypeClassMap bsonTypeClassMap)

Construct a new instance with the given registry and BSON type class map.

Parameters:

registry - the registry

bsonTypeClassMap - the BSON type class map

DocumentCodec

public DocumentCodec(CodecRegistry registry,
                     BsonTypeClassMap bsonTypeClassMap,
                     Transformer valueTransformer)

Construct a new instance with the given registry and BSON type class map. The transformer is applied as a last step when decoding values, which allows users of this codec to control the decoding process. For example, a user of this class could substitute a value decoded as a Document with an instance of a special purpose class (e.g., one representing a DBRef in MongoDB).

Parameters:

registry - the registry

bsonTypeClassMap - the BSON type class map

valueTransformer - the value transformer to use as a final step when decoding the value of any field in the document

Method Detail

documentHasId

public boolean documentHasId(Document document)

Description copied from interface: CollectibleCodec

Returns true if the given document has an _id.

Specified by:

documentHasId in interface CollectibleCodec<Document>

Parameters:

document - the document in which to look for an _id

Returns:

true if the document has an _id

getDocumentId

public BsonValue getDocumentId(Document document)

Description copied from interface: CollectibleCodec

Gets the _id of the given document if it contains one, otherwise throws IllegalArgumentException. To avoid the latter case, call documentHasId first to check.

Specified by:

getDocumentId in interface CollectibleCodec<Document>

Parameters:

document - the document from which to get the _id

Returns:

the _id of the document

generateIdIfAbsentFromDocument

public Document generateIdIfAbsentFromDocument(Document document)

Description copied from interface: CollectibleCodec

Generates a value for the _id field on the given document, if the document does not have one.

Specified by:

generateIdIfAbsentFromDocument in interface CollectibleCodec<Document>

Parameters:

document - the document for which to generate a value for the _id.

Returns:

the document with the _id

encode

public void encode(BsonWriter writer,
                   Document document,
                   EncoderContext encoderContext)

Description copied from interface: Encoder

Encode an instance of the type parameter T into a BSON value.

Specified by:

encode in interface Encoder<Document>

Parameters:

writer - the BSON writer to encode into

document - the value to encode

encoderContext - the encoder context

decode

public Document decode(BsonReader reader,
                       DecoderContext decoderContext)

Description copied from interface: Decoder

Decodes a BSON value from the given reader into an instance of the type parameter T.

Specified by:

decode in interface Decoder<Document>

Parameters:

reader - the BSON reader

decoderContext - the decoder context

Returns:

an instance of the type parameter T.

getEncoderClass

public Class<Document> getEncoderClass()

Description copied from interface: Encoder

Returns the Class instance that this encodes. This is necessary because Java does not reify generic types.

Specified by:

getEncoderClass in interface Encoder<Document>

Returns:

the Class instance that this encodes.