io.vertx.core.dns.impl.netty

Class DnsResponseDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.MessageToMessageDecoder<io.netty.channel.socket.DatagramPacket>

io.vertx.core.dns.impl.netty.DnsResponseDecoder

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler

public class DnsResponseDecoder
extends io.netty.handler.codec.MessageToMessageDecoder<io.netty.channel.socket.DatagramPacket>

DnsResponseDecoder accepts DatagramPacket and encodes to DnsResponse. This class also contains methods for decoding parts of DnsResponses such as questions and resource records.

Nested Class Summary

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

io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
DnsResponseDecoder()

Method Summary

Modifier and Type	Method and Description
protected void	decode(io.netty.channel.ChannelHandlerContext ctx, io.netty.channel.socket.DatagramPacket packet, List<Object> out) Decodes a response from a DatagramPacket containing a ByteBuf with a DNS packet.
protected static DnsResponse	decodeResponse(io.netty.buffer.ByteBuf buf, io.netty.buffer.ByteBufAllocator allocator) Decodes a full DNS response packet.
static String	getName(io.netty.buffer.ByteBuf buf, int offset) Retrieves a domain name given a buffer containing a DNS packet without advancing the readerIndex for the buffer.
static String	readName(io.netty.buffer.ByteBuf buf) Retrieves a domain name given a buffer containing a DNS packet.

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

acceptInboundMessage, channelRead

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

handlerAdded, handlerRemoved, 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, handlerRemoved

Constructor Detail

DnsResponseDecoder

public DnsResponseDecoder()

Method Detail

readName

public static String readName(io.netty.buffer.ByteBuf buf)

Retrieves a domain name given a buffer containing a DNS packet. If the name contains a pointer, the position of the buffer will be set to directly after the pointer's index after the name has been read.

Parameters:

buf - the byte buffer containing the DNS packet

Returns:

the domain name for an entry

getName

public static String getName(io.netty.buffer.ByteBuf buf,
                             int offset)

Retrieves a domain name given a buffer containing a DNS packet without advancing the readerIndex for the buffer.

Parameters:

buf - the byte buffer containing the DNS packet

offset - the position at which the name begins

Returns:

the domain name for an entry

decodeResponse

protected static DnsResponse decodeResponse(io.netty.buffer.ByteBuf buf,
                                            io.netty.buffer.ByteBufAllocator allocator)

Decodes a full DNS response packet.

Parameters:

buf - the raw DNS response packet

Returns:

the decoded DnsResponse

decode

protected void decode(io.netty.channel.ChannelHandlerContext ctx,
                      io.netty.channel.socket.DatagramPacket packet,
                      List<Object> out)
               throws Exception

Decodes a response from a DatagramPacket containing a ByteBuf with a DNS packet. Responses are sent from a DNS server to a client in response to a query. This method writes the decoded response to the specified List to be handled by a specialized message handler.

Specified by:

decode in class io.netty.handler.codec.MessageToMessageDecoder<io.netty.channel.socket.DatagramPacket>

Parameters:

ctx - the ChannelHandlerContext this DnsResponseDecoder belongs to

packet - the message being decoded, a DatagramPacket containing a DNS packet

out - the List to which decoded messages should be added

Throws:

Exception