cn.starboot.mqtt.codec

类 MqttDecoder

java.lang.Object

cn.starboot.mqtt.codec.MqttDecoder

public final class MqttDecoder
extends Object

Decodes Mqtt messages from bytes, following the MQTT protocol specification v3.1 or v5.0, depending on the version specified in the CONNECT message that first goes through the channel.

作者:

netty, L.cm, MDong

嵌套类概要

嵌套类

限定符和类型	类和说明
private static class	MqttDecoder.Result<T>

字段概要

字段

限定符和类型	字段和说明
private int	maxBytesInMessage
private int	maxClientIdLength

构造器概要

构造器

构造器和说明
MqttDecoder()
MqttDecoder(int maxBytesInMessage)
MqttDecoder(int maxBytesInMessage, int maxClientIdLength)

方法概要

限定符和类型	方法和说明
private MqttMessage	decode(ChannelContext ctx, ByteBuffer buffer, int readableLength)
private static byte[]	decodeByteArray(ByteBuffer buffer)
private static MqttDecoder.Result<MqttConnAckVariableHeader>	decodeConnAckVariableHeader(ChannelContext ctx, ByteBuffer buffer)
private static MqttDecoder.Result<MqttConnectPayload>	decodeConnectionPayload(ByteBuffer buffer, int maxClientIdLength, MqttConnectVariableHeader mqttConnectVariableHeader)
private static MqttDecoder.Result<MqttConnectVariableHeader>	decodeConnectionVariableHeader(ChannelContext ctx, ByteBuffer buffer)
private static MqttFixedHeader	decodeFixedHeader(ChannelContext ctx, ByteBuffer buffer) Decodes the fixed header.
private static int	decodeMessageId(ByteBuffer buffer, MqttFixedHeader mqttFixedHeader)
private static MqttDecoder.Result<MqttMessageIdAndPropertiesVariableHeader>	decodeMessageIdAndPropertiesVariableHeader(ChannelContext ctx, ByteBuffer buffer, MqttFixedHeader mqttFixedHeader)
private static int	decodeMsbLsb(ByteBuffer buffer) numberOfBytesConsumed = 2. return decoded result.
private static MqttDecoder.Result<?>	decodePayload(ByteBuffer buffer, int maxClientIdLength, MqttMessageType messageType, int bytesRemainingInVariablePart, Object variableHeader) Decodes the payload.
private static MqttDecoder.Result<MqttProperties>	decodeProperties(ByteBuffer buffer)
private static MqttDecoder.Result<ByteBuffer>	decodePublishPayload(ByteBuffer buffer, int bytesRemainingInVariablePart)
private MqttDecoder.Result<MqttPublishVariableHeader>	decodePublishVariableHeader(ChannelContext ctx, ByteBuffer buffer, MqttFixedHeader mqttFixedHeader)
private MqttDecoder.Result<MqttPubReplyMessageVariableHeader>	decodePubReplyMessage(ByteBuffer buffer, MqttFixedHeader mqttFixedHeader, int bytesRemainingInVariablePart)
private MqttDecoder.Result<MqttReasonCodeAndPropertiesVariableHeader>	decodeReasonCodeAndPropertiesVariableHeader(ByteBuffer buffer, int bytesRemainingInVariablePart)
private static MqttDecoder.Result<String>	decodeString(ByteBuffer buffer)
private static MqttDecoder.Result<String>	decodeString(ByteBuffer buffer, int minBytes, int maxBytes)
private static MqttDecoder.Result<MqttSubAckPayload>	decodeSubAckPayload(ByteBuffer buffer, int bytesRemainingInVariablePart)
private static MqttDecoder.Result<MqttSubscribePayload>	decodeSubscribePayload(ByteBuffer buffer, int bytesRemainingInVariablePart)
private static MqttDecoder.Result<MqttUnsubAckPayload>	decodeUnsubAckPayload(ByteBuffer buffer, int bytesRemainingInVariablePart)
private static MqttDecoder.Result<MqttUnsubscribePayload>	decodeUnsubscribePayload(ByteBuffer buffer, int bytesRemainingInVariablePart)
private static long	decodeVariableByteInteger(ByteBuffer buffer) See 1.5.5 Variable Byte Integer section of MQTT 5.0 specification for encoding/decoding rules
private MqttDecoder.Result<?>	decodeVariableHeader(ChannelContext ctx, ByteBuffer buffer, MqttFixedHeader mqttFixedHeader, int bytesRemainingInVariablePart) Decodes the variable header (if any)
MqttMessage	doDecode(ChannelContext ctx, cn.starboot.socket.utils.pool.memory.MemoryUnit memoryUnit)
private static long	packInts(int a, int b)
private static int	unpackA(long ints)
private static int	unpackB(long ints)

从类继承的方法 java.lang.Object

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

字段详细资料

maxBytesInMessage

private final int maxBytesInMessage

maxClientIdLength

private final int maxClientIdLength

构造器详细资料

MqttDecoder

public MqttDecoder()

MqttDecoder

public MqttDecoder(int maxBytesInMessage)

MqttDecoder

public MqttDecoder(int maxBytesInMessage,
                   int maxClientIdLength)

方法详细资料

doDecode

public MqttMessage doDecode(ChannelContext ctx,
                            cn.starboot.socket.utils.pool.memory.MemoryUnit memoryUnit)
                     throws AioDecoderException

抛出:

AioDecoderException

decode

private MqttMessage decode(ChannelContext ctx,
                           ByteBuffer buffer,
                           int readableLength)
                    throws AioDecoderException

抛出:

AioDecoderException

decodeFixedHeader

private static MqttFixedHeader decodeFixedHeader(ChannelContext ctx,
                                                 ByteBuffer buffer)

Decodes the fixed header. It's one byte for the flags and then variable bytes for the remaining length.

参数:

buffer - the buffer to decode from

返回:

the fixed header

decodeVariableHeader

private MqttDecoder.Result<?> decodeVariableHeader(ChannelContext ctx,
                                                   ByteBuffer buffer,
                                                   MqttFixedHeader mqttFixedHeader,
                                                   int bytesRemainingInVariablePart)

Decodes the variable header (if any)

参数:

buffer - the buffer to decode from

mqttFixedHeader - MqttFixedHeader of the same message

返回:

the variable header

decodeConnectionVariableHeader

private static MqttDecoder.Result<MqttConnectVariableHeader> decodeConnectionVariableHeader(ChannelContext ctx,
                                                                                            ByteBuffer buffer)

decodeConnAckVariableHeader

private static MqttDecoder.Result<MqttConnAckVariableHeader> decodeConnAckVariableHeader(ChannelContext ctx,
                                                                                         ByteBuffer buffer)

decodeMessageIdAndPropertiesVariableHeader

private static MqttDecoder.Result<MqttMessageIdAndPropertiesVariableHeader> decodeMessageIdAndPropertiesVariableHeader(ChannelContext ctx,
                                                                                                                       ByteBuffer buffer,
                                                                                                                       MqttFixedHeader mqttFixedHeader)

decodePubReplyMessage

private MqttDecoder.Result<MqttPubReplyMessageVariableHeader> decodePubReplyMessage(ByteBuffer buffer,
                                                                                    MqttFixedHeader mqttFixedHeader,
                                                                                    int bytesRemainingInVariablePart)

decodeReasonCodeAndPropertiesVariableHeader

private MqttDecoder.Result<MqttReasonCodeAndPropertiesVariableHeader> decodeReasonCodeAndPropertiesVariableHeader(ByteBuffer buffer,
                                                                                                                  int bytesRemainingInVariablePart)

decodePublishVariableHeader

private MqttDecoder.Result<MqttPublishVariableHeader> decodePublishVariableHeader(ChannelContext ctx,
                                                                                  ByteBuffer buffer,
                                                                                  MqttFixedHeader mqttFixedHeader)

decodeMessageId

private static int decodeMessageId(ByteBuffer buffer,
                                   MqttFixedHeader mqttFixedHeader)

返回:

messageId with numberOfBytesConsumed is 2

decodePayload

private static MqttDecoder.Result<?> decodePayload(ByteBuffer buffer,
                                                   int maxClientIdLength,
                                                   MqttMessageType messageType,
                                                   int bytesRemainingInVariablePart,
                                                   Object variableHeader)

Decodes the payload.

参数:

buffer - the buffer to decode from

messageType - type of the message being decoded

bytesRemainingInVariablePart - bytes remaining

variableHeader - variable header of the same message

返回:

the payload

decodeConnectionPayload

private static MqttDecoder.Result<MqttConnectPayload> decodeConnectionPayload(ByteBuffer buffer,
                                                                              int maxClientIdLength,
                                                                              MqttConnectVariableHeader mqttConnectVariableHeader)

decodeSubscribePayload

private static MqttDecoder.Result<MqttSubscribePayload> decodeSubscribePayload(ByteBuffer buffer,
                                                                               int bytesRemainingInVariablePart)

decodeSubAckPayload

private static MqttDecoder.Result<MqttSubAckPayload> decodeSubAckPayload(ByteBuffer buffer,
                                                                         int bytesRemainingInVariablePart)

decodeUnsubAckPayload

private static MqttDecoder.Result<MqttUnsubAckPayload> decodeUnsubAckPayload(ByteBuffer buffer,
                                                                             int bytesRemainingInVariablePart)

decodeUnsubscribePayload

private static MqttDecoder.Result<MqttUnsubscribePayload> decodeUnsubscribePayload(ByteBuffer buffer,
                                                                                   int bytesRemainingInVariablePart)

decodePublishPayload

private static MqttDecoder.Result<ByteBuffer> decodePublishPayload(ByteBuffer buffer,
                                                                   int bytesRemainingInVariablePart)

decodeString

private static MqttDecoder.Result<String> decodeString(ByteBuffer buffer)

decodeString

private static MqttDecoder.Result<String> decodeString(ByteBuffer buffer,
                                                       int minBytes,
                                                       int maxBytes)

decodeByteArray

private static byte[] decodeByteArray(ByteBuffer buffer)

返回:

the decoded byte[], numberOfBytesConsumed = byte[].length + 2

packInts

private static long packInts(int a,
                             int b)

unpackA

private static int unpackA(long ints)

unpackB

private static int unpackB(long ints)

decodeMsbLsb

private static int decodeMsbLsb(ByteBuffer buffer)

numberOfBytesConsumed = 2. return decoded result.

decodeVariableByteInteger

private static long decodeVariableByteInteger(ByteBuffer buffer)

See 1.5.5 Variable Byte Integer section of MQTT 5.0 specification for encoding/decoding rules

参数:

buffer - the buffer to decode from

返回:

result pack with a = decoded integer, b = numberOfBytesConsumed. Need to unpack to read them.

抛出:

DecoderException - if bad MQTT protocol limits Remaining Length

decodeProperties

private static MqttDecoder.Result<MqttProperties> decodeProperties(ByteBuffer buffer)