io.netty.handler.codec.serialization

Class ObjectDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.LengthFieldBasedFrameDecoder

io.netty.handler.codec.serialization.ObjectDecoder

All Implemented Interfaces:

ChannelHandler

public class ObjectDecoder
extends LengthFieldBasedFrameDecoder

A decoder which deserializes the received ByteBufs into Java objects.

Please note that the serialized form this decoder expects is not compatible with the standard ObjectOutputStream. Please use ObjectEncoder or ObjectEncoderOutputStream to ensure the interoperability with this decoder.

Nested Class Summary

Nested classes/interfaces inherited from class io.netty.handler.codec.ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable, ChannelHandler.Skip

Field Summary

Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor and Description
ObjectDecoder(ClassResolver classResolver) Creates a new decoder whose maximum object size is 1048576 bytes.
ObjectDecoder(int maxObjectSize, ClassResolver classResolver) Creates a new decoder with the specified maximum object size.

Method Summary

Methods

Modifier and Type	Method and Description
protected Object	decode(ChannelHandlerContext ctx, ByteBuf in) Create a frame out of the ByteBuf and return it.
protected ByteBuf	extractFrame(ChannelHandlerContext ctx, ByteBuf buffer, int index, int length) Extract the sub-region of the specified buffer.

Methods inherited from class io.netty.handler.codec.LengthFieldBasedFrameDecoder

decode, getUnadjustedFrameLength

Methods inherited from class io.netty.handler.codec.ByteToMessageDecoder

actualReadableBytes, callDecode, channelInactive, channelRead, channelReadComplete, decodeLast, handlerRemoved, handlerRemoved0, internalBuffer, isSingleDecode, setCumulator, setSingleDecode

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

bind, channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, exceptionCaught, flush, handlerAdded, isSharable, read, userEventTriggered, write

Methods inherited from class java.lang.Object

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

Constructor Detail

ObjectDecoder

public ObjectDecoder(ClassResolver classResolver)

Creates a new decoder whose maximum object size is 1048576 bytes. If the size of the received object is greater than 1048576 bytes, a StreamCorruptedException will be raised.

Parameters:

classResolver - the ClassResolver to use for this decoder

ObjectDecoder

public ObjectDecoder(int maxObjectSize,
             ClassResolver classResolver)

Creates a new decoder with the specified maximum object size.

Parameters:

maxObjectSize - the maximum byte length of the serialized object. if the length of the received object is greater than this value, StreamCorruptedException will be raised.

classResolver - the ClassResolver which will load the class of the serialized object

Method Detail

decode

protected Object decode(ChannelHandlerContext ctx,
            ByteBuf in)
                 throws Exception

Description copied from class: LengthFieldBasedFrameDecoder

Create a frame out of the ByteBuf and return it.

Overrides:

decode in class LengthFieldBasedFrameDecoder

Parameters:

ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs to

in - the ByteBuf from which to read data

Returns:

frame the ByteBuf which represent the frame or null if no frame could be created.

Throws:

Exception

extractFrame

protected ByteBuf extractFrame(ChannelHandlerContext ctx,
                   ByteBuf buffer,
                   int index,
                   int length)

Description copied from class: LengthFieldBasedFrameDecoder

Extract the sub-region of the specified buffer.

If you are sure that the frame and its content are not accessed after the current LengthFieldBasedFrameDecoder.decode(ChannelHandlerContext, ByteBuf) call returns, you can even avoid memory copy by returning the sliced sub-region (i.e. return buffer.slice(index, length)). It's often useful when you convert the extracted frame into an object. Refer to the source code of ObjectDecoder to see how this method is overridden to avoid memory copy.

Overrides:

extractFrame in class LengthFieldBasedFrameDecoder