com.datastax.driver.extras.codecs.arrays

Class ObjectArrayCodec<E>

java.lang.Object

com.datastax.driver.core.TypeCodec<T>

com.datastax.driver.extras.codecs.arrays.AbstractArrayCodec<E[]>

com.datastax.driver.extras.codecs.arrays.ObjectArrayCodec<E>

Type Parameters:

E - The Java array component type this codec handles

public class ObjectArrayCodec<E>
extends AbstractArrayCodec<E[]>

Codec dealing with Java object arrays. Serialization and deserialization of elements in the array is delegated to the provided element codec.

For example, to create a codec that maps list<text> to String[], declare the following:

 ObjectArrayCodec<String> stringArrayCodec = new ObjectArrayCodec<>(
      DataType.list(DataType.varchar()),
      String[].class,
      TypeCodec.varchar());
 

Nested Class Summary

Nested classes/interfaces inherited from class com.datastax.driver.core.TypeCodec

TypeCodec.AbstractCollectionCodec<E,C extends Collection<E>>, TypeCodec.AbstractMapCodec<K,V>, TypeCodec.AbstractTupleCodec<T>, TypeCodec.AbstractUDTCodec<T>, TypeCodec.PrimitiveBooleanCodec, TypeCodec.PrimitiveByteCodec, TypeCodec.PrimitiveDoubleCodec, TypeCodec.PrimitiveFloatCodec, TypeCodec.PrimitiveIntCodec, TypeCodec.PrimitiveLongCodec, TypeCodec.PrimitiveShortCodec

Field Summary

Fields

Modifier and Type	Field and Description
protected TypeCodec<E>	eltCodec

Fields inherited from class com.datastax.driver.core.TypeCodec

cqlType, javaType

Constructor Summary

Constructors

Constructor and Description
ObjectArrayCodec(DataType.CollectionType cqlType, Class<E[]> javaClass, TypeCodec<E> eltCodec)

Method Summary

Modifier and Type	Method and Description
E[]	deserialize(ByteBuffer bytes, ProtocolVersion protocolVersion) Deserialize the given ByteBuffer instance according to the CQL type handled by this codec.
protected void	formatElement(StringBuilder output, E[] array, int index) Format the indexth element of array to output.
protected E[]	newInstance(int size) Create a new array instance with the given size.
protected void	parseElement(String input, E[] array, int index) Parse the indexth element of array from input.
ByteBuffer	serialize(E[] value, ProtocolVersion protocolVersion) Serialize the given value according to the CQL type handled by this codec.

Methods inherited from class com.datastax.driver.extras.codecs.arrays.AbstractArrayCodec

format, parse

Methods inherited from class com.datastax.driver.core.TypeCodec

accepts, accepts, accepts, accepts, ascii, bigint, blob, cboolean, cdouble, cfloat, cint, counter, custom, date, decimal, getCqlType, getJavaType, inet, list, map, set, smallInt, time, timestamp, timeUUID, tinyInt, toString, tuple, userType, uuid, varchar, varint

Methods inherited from class java.lang.Object

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

Field Detail

eltCodec

protected final TypeCodec<E> eltCodec

Constructor Detail

ObjectArrayCodec

public ObjectArrayCodec(DataType.CollectionType cqlType,
                        Class<E[]> javaClass,
                        TypeCodec<E> eltCodec)

Method Detail

serialize

public ByteBuffer serialize(E[] value,
                            ProtocolVersion protocolVersion)

Description copied from class: TypeCodec

Serialize the given value according to the CQL type handled by this codec.

Implementation notes:

1. Null values should be gracefully handled and no exception should be raised; these should be considered as the equivalent of a NULL CQL value;
2. Codecs for CQL collection types should not permit null elements;
3. Codecs for CQL collection types should treat a null input as the equivalent of an empty collection.

Specified by:

serialize in class TypeCodec<E[]>

Parameters:

value - An instance of T; may be null.

protocolVersion - the protocol version to use when serializing bytes. In most cases, the proper value to provide for this argument is the value returned by ProtocolOptions.getProtocolVersion() (which is the protocol version in use by the driver).

Returns:

A ByteBuffer instance containing the serialized form of T

deserialize

public E[] deserialize(ByteBuffer bytes,
                       ProtocolVersion protocolVersion)

Description copied from class: TypeCodec

Deserialize the given ByteBuffer instance according to the CQL type handled by this codec.

Implementation notes:

1. Null or empty buffers should be gracefully handled and no exception should be raised; these should be considered as the equivalent of a NULL CQL value and, in most cases, should map to null or a default value for the corresponding Java type, if applicable;
2. Codecs for CQL collection types should clearly document whether they return immutable collections or not (note that the driver's default collection codecs return mutable collections);
3. Codecs for CQL collection types should avoid returning null; they should return empty collections instead (the driver's default collection codecs all comply with this rule).
4. The provided ByteBuffer should never be consumed by read operations that modify its current position; if necessary, ByteBuffer.duplicate() duplicate} it before consuming.

Specified by:

deserialize in class TypeCodec<E[]>

Parameters:

bytes - A ByteBuffer instance containing the serialized form of T; may be null or empty.

protocolVersion - the protocol version to use when serializing bytes. In most cases, the proper value to provide for this argument is the value returned by ProtocolOptions.getProtocolVersion() (which is the protocol version in use by the driver).

Returns:

An instance of T

formatElement

protected void formatElement(StringBuilder output,
                             E[] array,
                             int index)

Description copied from class: AbstractArrayCodec

Format the indexth element of array to output.

Specified by:

formatElement in class AbstractArrayCodec<E[]>

Parameters:

output - The StringBuilder to write to.

array - The array to read from.

index - The element index.

parseElement

protected void parseElement(String input,
                            E[] array,
                            int index)

Description copied from class: AbstractArrayCodec

Parse the indexth element of array from input.

Specified by:

parseElement in class AbstractArrayCodec<E[]>

Parameters:

input - The String to read from.

array - The array to write to.

index - The element index.

newInstance

protected E[] newInstance(int size)

Description copied from class: AbstractArrayCodec

Create a new array instance with the given size.

Specified by:

newInstance in class AbstractArrayCodec<E[]>

Parameters:

size - The size of the array to instantiate.

Returns:

a new array instance with the given size.