net.sf.xenqtt.message
Class UnsubscribeMessage

java.lang.Object
  net.sf.xenqtt.message.MqttMessage
      net.sf.xenqtt.message.IdentifiableMqttMessage
          net.sf.xenqtt.message.UnsubscribeMessage

public final class UnsubscribeMessage
extends IdentifiableMqttMessage

An UNSUBSCRIBE message is sent by the client to the server to unsubscribe from named topics.

The server sends an UNSUBACK to a client in response to an UNSUBSCRIBE message.

Constructor Summary

UnsubscribeMessage(ByteBuffer buffer, int remainingLength)
Used to construct a received message.

UnsubscribeMessage(int messageId, String[] topics)
Used to construct a message for sending

Method Summary

int	getMessageId() The message identifier is present in the variable header of the following MQTT messages: PUBLISH, PUBACK, PUBREC, PUBREL, PUBCOMP, SUBSCRIBE, SUBACK, UNSUBSCRIBE, UNSUBACK.
String[]	getTopics() The topics to unsubscribe from.
void	setMessageId(int messageId) Sets the message ID

Methods inherited from class net.sf.xenqtt.message.MqttMessage

byteBufferToHex, bytesToHex, equals, getMessageType, getQoS, getQoSLevel, getRemainingLength, isAck, isAckable, isDuplicate, isRetain, setDuplicateFlag, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

UnsubscribeMessage

public UnsubscribeMessage(ByteBuffer buffer,
                          int remainingLength)

Used to construct a received message.

UnsubscribeMessage

public UnsubscribeMessage(int messageId,
                          String[] topics)

Used to construct a message for sending

Method Detail

getMessageId

public int getMessageId()

Description copied from class: IdentifiableMqttMessage

The message identifier is present in the variable header of the following MQTT messages: PUBLISH, PUBACK, PUBREC, PUBREL, PUBCOMP, SUBSCRIBE, SUBACK, UNSUBSCRIBE, UNSUBACK.

The Message Identifier (Message ID) field is only present in messages where the QoS bits in the fixed header indicate QoS levels 1 or 2. See section on Quality of Service levels and flows for more information.

The Message ID is a 16-bit unsigned integer that must be unique amongst the set of "in flight" messages in a particular direction of communication. It typically increases by exactly one from one message to the next, but is not required to do so.

A client will maintain its own list of Message IDs separate to the Message IDs used by the server it is connected to. It is possible for a client to send a PUBLISH with Message ID 1 at the same time as receiving a PUBLISH with Message ID 1.

Do not use Message ID 0. It is reserved as an invalid Message ID.

Override this implementation for messages where the message ID is not at offset 2 of a fixed length message

Overrides:

getMessageId in class IdentifiableMqttMessage

See Also:

IdentifiableMqttMessage.getMessageId()

setMessageId

public void setMessageId(int messageId)

Description copied from class: IdentifiableMqttMessage

Sets the message ID

Override this implementation for messages where the message ID is not at offset 2 of a fixed length message

Overrides:

setMessageId in class IdentifiableMqttMessage

See Also:

IdentifiableMqttMessage.setMessageId(int)

getTopics

public String[] getTopics()

The topics to unsubscribe from.