io.netty.handler.codec.dns

Class TcpDnsResponseDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder

io.netty.handler.codec.LengthFieldBasedFrameDecoder

io.netty.handler.codec.dns.TcpDnsResponseDecoder

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler

@UnstableApi
public final class TcpDnsResponseDecoder
extends LengthFieldBasedFrameDecoder

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

Field Summary

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

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor and Description
TcpDnsResponseDecoder() Creates a new decoder with the default record decoder.
TcpDnsResponseDecoder(DnsRecordDecoder recordDecoder, int maxFrameLength) Creates a new decoder with the specified recordDecoder and maxFrameLength

Method Summary

Modifier and Type	Method and Description
protected java.lang.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, discardSomeReadBytes, handlerRemoved, handlerRemoved0, internalBuffer, isSingleDecode, setCumulator, setDiscardAfterReads, setSingleDecode, userEventTriggered

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, isSharable

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.ChannelHandler

handlerAdded

Constructor Detail

TcpDnsResponseDecoder

public TcpDnsResponseDecoder()

Creates a new decoder with the default record decoder.

TcpDnsResponseDecoder

public TcpDnsResponseDecoder(DnsRecordDecoder recordDecoder,
                             int maxFrameLength)

Creates a new decoder with the specified recordDecoder and maxFrameLength

Method Detail

decode

protected java.lang.Object decode(ChannelHandlerContext ctx,
                                  ByteBuf in)
                           throws java.lang.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:

java.lang.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