com.aquenos.epics.jackie.common.protocol

Class ChannelAccessVersionMessage

java.lang.Object

com.aquenos.epics.jackie.common.protocol.ChannelAccessMessage

com.aquenos.epics.jackie.common.protocol.ChannelAccessVersionMessage

Direct Known Subclasses:

ChannelAccessVersionTCPClientMessage, ChannelAccessVersionTCPServerMessage, ChannelAccessVersionUDPMessage

public abstract class ChannelAccessVersionMessage
extends ChannelAccessMessage

Base class for representations of a CA_PROTO_VERSION message. This message is mainly used for communicating the supported protocol version, however, depending on the context it might carry additional information. As the meaning of this message is different depending on the context (direction and base protocol) there are different child classes for the different use cases.

Author:

Sebastian Marsching

See Also:

ChannelAccessCommand.CA_PROTO_VERSION

Field Summary

Fields

Modifier and Type	Field and Description
protected ChannelAccessVersion	version Channel Access version as enum.

Fields inherited from class com.aquenos.epics.jackie.common.protocol.ChannelAccessMessage

command, originalMessageHeader

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj) Tells whether the specified object represents the same message.
ChannelAccessVersion	getVersion() Returns the Channel Access version supported by the peer sending this message.
int	hashCode() Returns a hash code value for this message.

Methods inherited from class com.aquenos.epics.jackie.common.protocol.ChannelAccessMessage

addByteArrayToStringBuilder, calculatePaddingSize, getCommand, getOriginalMessageHeader, hasOriginalMessageHeader, serialize, serializeHeader, toString, verify, verifyHeader

Methods inherited from class java.lang.Object

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

Field Detail

version

protected ChannelAccessVersion version

Channel Access version as enum. This is cached on object creation, so that we can avoid the whole process of looking up the right enum each time the property is read. The extra memory overhead seems to be acceptable in comparison to the gain.

Method Detail

getVersion

public ChannelAccessVersion getVersion()

Returns the Channel Access version supported by the peer sending this message. This information can be used by the receiving peer to decide which features of the protocol it can use.

Returns:

Channel Access version supported by the sending peer.

equals

public boolean equals(java.lang.Object obj)

Description copied from class: 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.

Overrides:

equals in class ChannelAccessMessage

Parameters:

obj - reference object with which this object is compared.

Returns:

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.

hashCode

public int hashCode()

Description copied from class: 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.

Overrides:

hashCode in class ChannelAccessMessage

Returns:

hash code suitable for use by a hash table.