com.couchbase.client.java.transcoder.subdoc

Class JacksonFragmentTranscoder

java.lang.Object

com.couchbase.client.java.transcoder.subdoc.AbstractFragmentTranscoder

com.couchbase.client.java.transcoder.subdoc.AbstractByteArrayFragmentTranscoder

com.couchbase.client.java.transcoder.subdoc.JacksonFragmentTranscoder

All Implemented Interfaces:

FragmentTranscoder

@InterfaceStability.Uncommitted
 @InterfaceAudience.Private
public class JacksonFragmentTranscoder
extends AbstractByteArrayFragmentTranscoder

A Jackson-based implementation of a FragmentTranscoder, based on AbstractByteArrayFragmentTranscoder. This implementation changes the decodeWithMessage behavior compared to the parent strategy by attempting to deserialize JSON arrays into JsonArray and JSON dictionaries into JsonObject. Care should be taken to not use Jackson specific annotations if you want to be able to easily swap this for another SubdocumentTranscoder implementation at a later time.

Since:

2.2

Author:

Simon Baslé

Constructor Summary

Constructors

Constructor and Description
JacksonFragmentTranscoder(com.couchbase.client.deps.com.fasterxml.jackson.databind.ObjectMapper mapper)

Method Summary

Modifier and Type	Method and Description
protected <T> T	byteArrayToClass(byte[] byteArray, int offset, int length, Class<? extends T> clazz) Deserializes a byte array into a specific class instance.
protected Object	byteArrayToGenericObject(byte[] byteArray, int offset, int length) Deserializes a byte array into a generic Object.
<T> T	decodeWithMessage(com.couchbase.client.deps.io.netty.buffer.ByteBuf encoded, Class<? extends T> clazz, String transcodingErrorMessage) Decode content in a ByteBuf **without releasing it**.
protected <T> byte[]	writeValueAsBytes(T value) Serializes a single value object as an array of bytes.
protected void	writeValueIntoStream(OutputStream out, Object o) Serializes a single object out of a sequence of multiple values, into the sequence's OutputStream.

Methods inherited from class com.couchbase.client.java.transcoder.subdoc.AbstractByteArrayFragmentTranscoder

doEncodeMulti, doEncodeSingle

Methods inherited from class com.couchbase.client.java.transcoder.subdoc.AbstractFragmentTranscoder

decode, encode, encodeWithMessage

Methods inherited from class java.lang.Object

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

Constructor Detail

JacksonFragmentTranscoder

public JacksonFragmentTranscoder(com.couchbase.client.deps.com.fasterxml.jackson.databind.ObjectMapper mapper)

Method Detail

decodeWithMessage

public <T> T decodeWithMessage(com.couchbase.client.deps.io.netty.buffer.ByteBuf encoded,
                               Class<? extends T> clazz,
                               String transcodingErrorMessage)
                        throws TranscodingException

Description copied from interface: FragmentTranscoder

Decode content in a ByteBuf **without releasing it**. Suitable for populating a DocumentFragment's content.

Specified by:

decodeWithMessage in interface FragmentTranscoder

Overrides:

decodeWithMessage in class AbstractByteArrayFragmentTranscoder

Type Parameters:

T - the type of the decoded fragment.

Parameters:

encoded - the encoded fragment value (will not be released).

clazz - the target class for decoded value. Using Object.class implies a generic decode, where dictionaries are represented by JsonObject and arrays by JsonArray.

transcodingErrorMessage - the error message to be used in the thrown TranscodingException if the decoding couldn't happen.

Returns:

a decoded fragment.

Throws:

TranscodingException - if the decoding couldn't happen.

byteArrayToGenericObject

protected Object byteArrayToGenericObject(byte[] byteArray,
                                          int offset,
                                          int length)
                                   throws IOException

Description copied from class: AbstractByteArrayFragmentTranscoder

Deserializes a byte array into a generic Object. The provided offset and length must be considered when processing the array, which may hold more data that just the value to deserialize. Note that he byte array should not be considered reliable for long-term usage (eg. backing a String) as it might be tied to the original ByteBuf, which will get released from the heap. If the array represents a non-scalar value, implementations may choose different classes like a JsonObject or a Map to instantiate it. This method is called by AbstractByteArrayFragmentTranscoder.decodeWithMessage(ByteBuf, Class, String) when the clazz parameter is Object.class.

Specified by:

byteArrayToGenericObject in class AbstractByteArrayFragmentTranscoder

Parameters:

byteArray - the array of bytes containing the value to deserialize (you'll need to copy it if long term usage is needed).

offset - the offset in the array at which the value starts.

length - the number of bytes after the offset that represents the value.

Returns:

an instance of a suitable generic Object representation of the value.

Throws:

IOException

byteArrayToClass

protected <T> T byteArrayToClass(byte[] byteArray,
                                 int offset,
                                 int length,
                                 Class<? extends T> clazz)
                          throws IOException

Description copied from class: AbstractByteArrayFragmentTranscoder

Deserializes a byte array into a specific class instance. The provided offset and length must be considered when processing the array, which may hold more data that just the value to deserialize. Note that he byte array should not be considered reliable for long-term usage (eg. backing a String) as it might be tied to the original ByteBuf, which will get released from the heap. This method is called by AbstractByteArrayFragmentTranscoder.decodeWithMessage(ByteBuf, Class, String) when the clazz parameter isn't Object.class.

Specified by:

byteArrayToClass in class AbstractByteArrayFragmentTranscoder

Parameters:

byteArray - the array of bytes containing the value to deserialize (you'll need to copy it if long term usage is needed).

offset - the offset in the array at which the value starts.

length - the number of bytes after the offset that represents the value.

clazz - the Class to deserialize to.

Returns:

an instance of a suitable generic Object representation of the value.

Throws:

IOException

writeValueAsBytes

protected <T> byte[] writeValueAsBytes(T value)
                                throws IOException

Description copied from class: AbstractByteArrayFragmentTranscoder

Serializes a single value object as an array of bytes. The array will be backing a ByteBuf, so modifications to the array will be visible in the ByteBuf.

Specified by:

writeValueAsBytes in class AbstractByteArrayFragmentTranscoder

Parameters:

value - the value object to serialize.

Returns:

the array of bytes representing the serialized value object.

Throws:

IOException

writeValueIntoStream

protected void writeValueIntoStream(OutputStream out,
                                    Object o)
                             throws IOException

Description copied from class: AbstractByteArrayFragmentTranscoder

Serializes a single object out of a sequence of multiple values, into the sequence's OutputStream. Implementation should simply write the bytes corresponding to the serialized value object into the stream.

Specified by:

writeValueIntoStream in class AbstractByteArrayFragmentTranscoder

Parameters:

out - the OutputStream of bytes representing a JSON sequence of serialized values.

o - the value among the sequence that is currently serialized.

Throws:

IOException