public final class ChannelAccessCancelSubscriptionServerMessage extends ChannelAccessSubscriptionMessage
Representation of a CA_PROTO_EVENT_ADD
message that is sent from
a server to a client. This message is sent in response to a subscription
cancellation request.
For some historic reasons, the server sends this message instead of a
CA_PROTO_EVENT_CANCEL
message in response to a
ChannelAccessCancelSubscriptionClientMessage
. The only way to tell
this message apart from a ChannelAccessSubscriptionServerMessage
is
by its payload size. This message always has a zero payload size, while the
ChannelAccessSubscriptionServerMessage
always has a non-zero payload
size.
ChannelAccessCommand.CA_PROTO_EVENT_ADD
,
ChannelAccessSubscriptionClientMessage
,
ChannelAccessSubscriptionServerMessage
,
ChannelAccessCancelSubscriptionClientMessage
command, originalMessageHeader
Constructor and Description |
---|
ChannelAccessCancelSubscriptionServerMessage(ChannelAccessValueType dataType,
int count,
int sid,
int subscriptionId)
Creates a
CA_PROTO_EVENT_ADD message. |
Modifier and Type | Method and Description |
---|---|
protected static ChannelAccessCancelSubscriptionServerMessage |
deserialize(ChannelAccessMessageHeader messageHeader,
ByteSource byteSource)
Constructs a message from a header and a byte source.
|
boolean |
equals(Object obj)
Tells whether the specified object represents the same message.
|
int |
getChannelSID()
Returns the channel ID that is used by the server to identify the
channel.
|
int |
getCount()
Returns the number of elements the value in this message's payload has.
|
ChannelAccessValueType |
getDataType()
Returns the data type of the value in this message's payload.
|
int |
getSubscriptionId()
Returns the client-assigned subscription ID.
|
int |
hashCode()
Returns a hash code value for this message.
|
protected void |
serialize(ByteSink byteSink,
ChannelAccessVersion version,
int maxPayloadSize,
Charset charset)
Serializes this message to a byte sink.
|
String |
toString()
Returns a string representation of this message.
|
protected void |
verify(ChannelAccessVersion version,
int maxPayloadSize,
Charset charset)
Verifies that this message can be serialized.
|
addByteArrayToStringBuilder, calculatePaddingSize, getCommand, getOriginalMessageHeader, hasOriginalMessageHeader, serializeHeader, verifyHeader
public ChannelAccessCancelSubscriptionServerMessage(ChannelAccessValueType dataType, int count, int sid, int subscriptionId)
CA_PROTO_EVENT_ADD
message. This constructor
should be used to create a message that is sent from a server to a client
in response to a ChannelAccessCancelSubscriptionClientMessage
sent by the client.dataType
- data type sent in the client's request.count
- count sent in the client's request.sid
- the channel identifier used by the server.subscriptionId
- client-assigned subscription ID. This ID must be the same ID
that was sent with the client's request.public ChannelAccessValueType getDataType()
null
if the specified data-type is unknown to this
implementation.null
if the numeric
identifier cannot be mapped to a data type known by this
implementation.public int getCount()
public int getChannelSID()
public int getSubscriptionId()
protected void serialize(ByteSink byteSink, ChannelAccessVersion version, int maxPayloadSize, Charset charset)
ChannelAccessMessage
ChannelAccessMessageCodec
.serialize
in class ChannelAccessMessage
byteSink
- byte sink that is used for writing the serialized data.version
- protocol version to stay compatible with. This is the protocol
version of the peer the message is sent to.maxPayloadSize
- maximum size of the payload.charset
- encoding to use for serializing the string data (e.g. channel
names, error strings, string data-values).protected void verify(ChannelAccessVersion version, int maxPayloadSize, Charset charset)
ChannelAccessMessage
ChannelAccessMessageCodec
.verify
in class ChannelAccessMessage
version
- protocol version to stay compatible with. This is the protocol
version of the peer the message is sent to.maxPayloadSize
- maximum size of the payload.charset
- encoding to use for serializing the string data (e.g. channel
names, error strings, string data-values).public boolean equals(Object obj)
ChannelAccessMessage
Tells whether the specified object represents the same message.
Two messages are considered equal if they are of the same type and have the same headers and payload. For comparing the types, the actual Java type and not just the Channel Access command is compared.
equals
in class ChannelAccessMessage
obj
- reference object with which this object is compared.true
if obj
is a message that is of the
same type and has the same headers and payload as this message.
false
if obj
is null
or of
a different type than this message or differs in the headers or
payload.public int hashCode()
ChannelAccessMessage
Returns a hash code value for this message. This method is supported for the benefit of hash tables. The hash code is calculated as a combination of the hash codes of this messages headers (including the Channel Access command) and its payload (if present).
If two messages are equal (as indicated by the return value of
ChannelAccessMessage.equals(Object)
), they also have the same hash code. However, the
fact that two messages have the same hash code does not imply that they
are equal.
hashCode
in class ChannelAccessMessage
public String toString()
ChannelAccessMessage
toString
in class ChannelAccessMessage
protected static ChannelAccessCancelSubscriptionServerMessage deserialize(ChannelAccessMessageHeader messageHeader, ByteSource byteSource)
ChannelAccessMessageCodec
.messageHeader
- CA message header.byteSource
- byte source for reading the message's payload (if any).headerOnly
is
false
).BufferUnderflowException
- if there is not enough data in the byte source to read the
complete payload.ShortPayloadException
- if the message's payload size is less than the size needed
for the data type and count.Copyright © 2014–2017 aquenos GmbH. All rights reserved.