io.netty.handler.codec.serialization

Class ObjectDecoder

java.lang.Object

io.netty.channel.ChannelStateHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder<Object>

io.netty.handler.codec.LengthFieldBasedFrameDecoder

io.netty.handler.codec.serialization.ObjectDecoder

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundByteHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelStateHandler

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 interface io.netty.channel.ChannelHandler

io.netty.channel.ChannelHandler.Sharable

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
Object	decode(io.netty.channel.ChannelHandlerContext ctx, io.netty.buffer.ByteBuf in)
protected io.netty.buffer.ByteBuf	extractFrame(io.netty.buffer.ByteBuf buffer, int index, int length) Extract the sub-region of the specified buffer.

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

beforeAdd, callDecode, channelInactive, decodeLast, inboundBufferUpdated, newInboundBuffer, replace

Methods inherited from class io.netty.channel.ChannelStateHandlerAdapter

afterAdd, afterRemove, beforeRemove, channelActive, channelRegistered, channelUnregistered, exceptionCaught, userEventTriggered

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelStateHandler

channelActive, channelRegistered, channelUnregistered

Methods inherited from interface io.netty.channel.ChannelHandler

afterAdd, afterRemove, beforeRemove, exceptionCaught, userEventTriggered

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

public Object decode(io.netty.channel.ChannelHandlerContext ctx,
            io.netty.buffer.ByteBuf in)
              throws Exception

Overrides:

decode in class LengthFieldBasedFrameDecoder

Throws:

Exception

extractFrame

protected io.netty.buffer.ByteBuf extractFrame(io.netty.buffer.ByteBuf buffer,
                                   int index,
                                   int length)

Description copied from class: LengthFieldBasedFrameDecoder

Extract the sub-region of the specified buffer. This method is called by #decode(ChannelInboundHandlerContext, ByteBuf) for each frame. The default implementation returns a copy of the sub-region. For example, you could override this method to use an alternative ByteBufFactory.

If you are sure that the frame and its content are not accessed after the current #decode(ChannelInboundHandlerContext, 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