Package io.netty.handler.codec.mqtt

Class MqttEncoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelOutboundHandlerAdapter

io.netty.handler.codec.MessageToMessageEncoder<MqttMessage>

io.netty.handler.codec.mqtt.MqttEncoder

All Implemented Interfaces:

ChannelHandler, ChannelOutboundHandler

@Sharable
public final class MqttEncoder
extends MessageToMessageEncoder<MqttMessage>

Encodes Mqtt messages into bytes following the protocol specification v3.1 as described here MQTTV3.1 or v5.0 as described here MQTTv5.0 - depending on the version specified in the first CONNECT message that goes through the channel.

Nested Class Summary

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

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
static final MqttEncoder	INSTANCE

Constructor Summary

Constructors

Modifier	Constructor	Description
private	MqttEncoder()

Method Summary

Modifier and Type	Method	Description
(package private) static ByteBuf	doEncode(ChannelHandlerContext ctx, MqttMessage message)	This is the main encoding method.
protected void	encode(ChannelHandlerContext ctx, MqttMessage msg, List<Object> out)	Encode from one message to an other.
private static ByteBuf	encodeConnAckMessage(ChannelHandlerContext ctx, MqttConnAckMessage message)
private static ByteBuf	encodeConnectMessage(ChannelHandlerContext ctx, MqttConnectMessage message)
private static ByteBuf	encodeMessageWithOnlySingleByteFixedHeader(ByteBufAllocator byteBufAllocator, MqttMessage message)
private static ByteBuf	encodeMessageWithOnlySingleByteFixedHeaderAndMessageId(ByteBufAllocator byteBufAllocator, MqttMessage message)
private static ByteBuf	encodeProperties(ByteBufAllocator byteBufAllocator, MqttProperties mqttProperties)
private static ByteBuf	encodePropertiesIfNeeded(MqttVersion mqttVersion, ByteBufAllocator byteBufAllocator, MqttProperties mqttProperties)
private static ByteBuf	encodePublishMessage(ChannelHandlerContext ctx, MqttPublishMessage message)
private static ByteBuf	encodePubReplyMessage(ChannelHandlerContext ctx, MqttMessage message)
private static ByteBuf	encodeReasonCodePlusPropertiesMessage(ChannelHandlerContext ctx, MqttMessage message)
private static ByteBuf	encodeSubAckMessage(ChannelHandlerContext ctx, MqttSubAckMessage message)
private static ByteBuf	encodeSubscribeMessage(ChannelHandlerContext ctx, MqttSubscribeMessage message)
private static ByteBuf	encodeUnsubAckMessage(ChannelHandlerContext ctx, MqttUnsubAckMessage message)
private static ByteBuf	encodeUnsubscribeMessage(ChannelHandlerContext ctx, MqttUnsubscribeMessage message)
private static int	getConnVariableHeaderFlag(MqttConnectVariableHeader variableHeader)
private static int	getFixedHeaderByte1(MqttFixedHeader header)
private static int	getVariableLengthInt(int num)
private static int	nullableMaxUtf8Bytes(String s)
private static int	nullableUtf8Bytes(String s)
private static void	writeEagerUTF8String(ByteBuf buf, String s)
private static void	writeExactUTF8String(ByteBuf buf, String s, int utf8Length)
private static void	writeVariableLengthInt(ByteBuf buf, int num)

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

acceptOutboundMessage, write

Methods inherited from class io.netty.channel.ChannelOutboundHandlerAdapter

bind, close, connect, deregister, disconnect, flush, read

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, exceptionCaught, 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

exceptionCaught, handlerAdded, handlerRemoved

Field Details

INSTANCE

public static final MqttEncoder INSTANCE

Constructor Details

MqttEncoder

private MqttEncoder()

Method Details

encode

protected void encode(ChannelHandlerContext ctx,
 MqttMessage msg,
 List<Object> out)
               throws Exception

Description copied from class: MessageToMessageEncoder

Encode from one message to an other. This method will be called for each written message that can be handled by this encoder.

Specified by:

encode in class MessageToMessageEncoder<MqttMessage>

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to

msg - the message to encode to an other one

out - the List into which the encoded msg should be added needs to do some kind of aggregation

Throws:

Exception - is thrown if an error occurs

doEncode

static ByteBuf doEncode(ChannelHandlerContext ctx,
 MqttMessage message)

This is the main encoding method. It's only visible for testing.

Parameters:

message - MQTT message to encode

Returns:

ByteBuf with encoded bytes

encodeConnectMessage

private static ByteBuf encodeConnectMessage(ChannelHandlerContext ctx,
 MqttConnectMessage message)

getConnVariableHeaderFlag

private static int getConnVariableHeaderFlag(MqttConnectVariableHeader variableHeader)

encodeConnAckMessage

private static ByteBuf encodeConnAckMessage(ChannelHandlerContext ctx,
 MqttConnAckMessage message)

encodeSubscribeMessage

private static ByteBuf encodeSubscribeMessage(ChannelHandlerContext ctx,
 MqttSubscribeMessage message)

encodeUnsubscribeMessage

private static ByteBuf encodeUnsubscribeMessage(ChannelHandlerContext ctx,
 MqttUnsubscribeMessage message)

encodeSubAckMessage

private static ByteBuf encodeSubAckMessage(ChannelHandlerContext ctx,
 MqttSubAckMessage message)

encodeUnsubAckMessage

private static ByteBuf encodeUnsubAckMessage(ChannelHandlerContext ctx,
 MqttUnsubAckMessage message)

encodePublishMessage

private static ByteBuf encodePublishMessage(ChannelHandlerContext ctx,
 MqttPublishMessage message)

encodePubReplyMessage

private static ByteBuf encodePubReplyMessage(ChannelHandlerContext ctx,
 MqttMessage message)

encodeMessageWithOnlySingleByteFixedHeaderAndMessageId

private static ByteBuf encodeMessageWithOnlySingleByteFixedHeaderAndMessageId(ByteBufAllocator byteBufAllocator,
 MqttMessage message)

encodeReasonCodePlusPropertiesMessage

private static ByteBuf encodeReasonCodePlusPropertiesMessage(ChannelHandlerContext ctx,
 MqttMessage message)

encodeMessageWithOnlySingleByteFixedHeader

private static ByteBuf encodeMessageWithOnlySingleByteFixedHeader(ByteBufAllocator byteBufAllocator,
 MqttMessage message)

encodePropertiesIfNeeded

private static ByteBuf encodePropertiesIfNeeded(MqttVersion mqttVersion,
 ByteBufAllocator byteBufAllocator,
 MqttProperties mqttProperties)

encodeProperties

private static ByteBuf encodeProperties(ByteBufAllocator byteBufAllocator,
 MqttProperties mqttProperties)

getFixedHeaderByte1

private static int getFixedHeaderByte1(MqttFixedHeader header)

writeVariableLengthInt

private static void writeVariableLengthInt(ByteBuf buf,
 int num)

nullableUtf8Bytes

private static int nullableUtf8Bytes(String s)

nullableMaxUtf8Bytes

private static int nullableMaxUtf8Bytes(String s)

writeExactUTF8String

private static void writeExactUTF8String(ByteBuf buf,
 String s,
 int utf8Length)

writeEagerUTF8String

private static void writeEagerUTF8String(ByteBuf buf,
 String s)

getVariableLengthInt

private static int getVariableLengthInt(int num)