Please note that this documentation is not final and is subject to change.

JavaTM SCTP API
DRAFT ea-b11

com.sun.nio.sctp
Class MessageInfo

java.lang.Object
  extended by com.sun.nio.sctp.MessageInfo

public abstract class MessageInfo
extends Object

The MessageInfo class provides additional ancillary information about messages.

Received SCTP messages, returned by SctpChannel.receive and SctpMultiChannel.receive, return a MessageInfo instance that can be queried to determine ancillary information about the received message. Messages being sent should use one of the createOutgoing methods to provide ancillary data for the message being sent, and may use the appropriate setter methods to override the default values provided for unordered, timeToLive, complete and payloadProtocolID, before sending the message.

For out going messages the timeToLive parameter is a time period that the sending side SCTP stack may expire the message if it has not been sent. This time period is an indication to the stack that the message is no longer required to be sent after the time period expires. It is not a hard timeout and may be influenced by whether the association supports the partial reliability extension, RFC 3758

MessageInfo instances are not safe for use by multiple concurrent threads. If a MessageInfo is to be used by more than one thread then access to the MessageInfo should be controlled by appropriate synchronization.

Since:
1.7

Constructor Summary
protected MessageInfo()
          Initializes a new instance of this class.
 
Method Summary
abstract  SocketAddress address()
          Returns the source socket address if the message has been received, otherwise the preferred destination of the message to be sent.
abstract  Association association()
          Returns the association that the message was received on, if the message has been received, otherwise the association that the message is to be sent on.
abstract  int bytes()
          Returns the number of bytes read for the received message.
abstract  MessageInfo complete(boolean complete)
          Sets whether or not the message is complete.
static MessageInfo createOutgoing(Association association, SocketAddress address, int streamNumber)
          Creates a MessageInfo instance suitable for use when sending a message to a given association.
static MessageInfo createOutgoing(SocketAddress address, int streamNumber)
          Creates a MessageInfo instance suitable for use when sending a message.
abstract  boolean isComplete()
          Tells whether or not the message is complete.
abstract  boolean isUnordered()
          Tells whether or not the message is unordered.
abstract  int payloadProtocolID()
          Returns the payload protocol Identifier.
abstract  MessageInfo payloadProtocolID(int ppid)
          Sets the payload protocol Identifier.
abstract  int streamNumber()
          Returns the stream number that the message was received on, if the message has been received, otherwise the stream number that the message is to be sent on.
abstract  MessageInfo streamNumber(int streamNumber)
          Sets the stream number that the message is to be sent on.
abstract  long timeToLive()
          The time period that the sending side may expire the message if it has not been sent, or 0 to indicate that no timeout should occur.
abstract  MessageInfo timeToLive(long millis)
          Sets the time period that the sending side may expire the message if it has not been sent.
abstract  MessageInfo unordered(boolean unordered)
          Sets whether or not the message is unordered.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MessageInfo

protected MessageInfo()
Initializes a new instance of this class.

Method Detail

createOutgoing

public static MessageInfo createOutgoing(SocketAddress address,
                                         int streamNumber)
Creates a MessageInfo instance suitable for use when sending a message.

The returned instance will have its unordered value set to false, its timeToLive value set to 0, its complete value set to true, and its payloadProtocolID value set to 0. These values, if required, can be set through the appropriate setter method before sending the message.

Parameters:
address - For a connected SctpChannel the address is the preferred peer address of the association to send the message to, or null to use the peer primary address. For an SctpMultiChannel the address is used to determine the association, or if no association exists with a peer of that address then one is setup.
streamNumber - The stream number that the message will be sent on
Returns:
The outgoing message info
Throws:
IllegalArgumentException - If the streamNumber is negative or greater than 65536

createOutgoing

public static MessageInfo createOutgoing(Association association,
                                         SocketAddress address,
                                         int streamNumber)
Creates a MessageInfo instance suitable for use when sending a message to a given association. Typically used for SctpMultiChannel when an association has already been setup.

The returned instance will have its unordered value set to false, its timeToLive value set to 0, its complete value set to true, and its payloadProtocolID value set to 0. These values, if required, can be set through the appropriate setter method before sending the message.

Parameters:
association - The association to send the message on
address - The preferred peer address of the association to send the message to, or null to use the peer primary address
streamNumber - The stream number that the message will be sent on.
Returns:
The outgoing message info
Throws:
IllegalArgumentException - If association is null, or the streamNumber is negative or greater than 65536

address

public abstract SocketAddress address()
Returns the source socket address if the message has been received, otherwise the preferred destination of the message to be sent.

Returns:
The socket address, or null if this instance is to be used for sending a message and has been construced without specifying a preferred destination address

association

public abstract Association association()
Returns the association that the message was received on, if the message has been received, otherwise the association that the message is to be sent on.

Returns:
The association, or null if this instance is to be used for sending a message and has been construced using the the createOutgoing(SocketAddress,int) static factory method

bytes

public abstract int bytes()
Returns the number of bytes read for the received message.

This method is only appicable for received messages, it has no meaning for messages being sent.

Returns:
The number of bytes read, -1 if the channel is an SctpChannel that has reached end-of-stream, otherwise 0

isComplete

public abstract boolean isComplete()
Tells whether or not the message is complete.

For received messages true indicates that the message was completely received. For messages being sent true indicates that the message is complete, false indicates that the message is not complete. How the send channel interprets this value depends on the value of its SCTP_EXPLICIT_COMPLETE socket option.

Returns:
true if, and only if, the message is complete

complete

public abstract MessageInfo complete(boolean complete)
Sets whether or not the message is complete.

For messages being sent true indicates that the message is complete, false indicates that the message is not complete. How the send channel interprets this value depends on the value of its SCTP_EXPLICIT_COMPLETE socket option.

Parameters:
complete - true if, and only if, the message is complete
Returns:
This MessageInfo
See Also:
isComplete()

isUnordered

public abstract boolean isUnordered()
Tells whether or not the message is unordered. For received messages true indicates that the message was sent non-ordered. For messages being sent true requests the un-ordered delivery of the message, false indicates that the message is ordered.

Returns:
true if the message is unordered, otherwise false

unordered

public abstract MessageInfo unordered(boolean unordered)
Sets whether or not the message is unordered.

Parameters:
unordered - true requests the un-ordered delivery of the message, false indicates that the message is ordered.
Returns:
This MessageInfo
See Also:
isUnordered()

payloadProtocolID

public abstract int payloadProtocolID()
Returns the payload protocol Identifier.

A value indicating the type of payload protocol data being transmitted/received. This value is passed as opaque data by SCTP. 0 indicates an unspecified payload protocol identifier.

Returns:
The Payload Protocol Identifier

payloadProtocolID

public abstract MessageInfo payloadProtocolID(int ppid)
Sets the payload protocol Identifier.

A value indicating the type of payload protocol data being transmitted. This value is passed as opaque data by SCTP.

Parameters:
ppid - The Payload Protocol Identifier, or 0 indicate an unspecified payload protocol identifier.
Returns:
This MessageInfo
See Also:
payloadProtocolID()

streamNumber

public abstract int streamNumber()
Returns the stream number that the message was received on, if the message has been received, otherwise the stream number that the message is to be sent on.

Returns:
The stream number

streamNumber

public abstract MessageInfo streamNumber(int streamNumber)
Sets the stream number that the message is to be sent on.

Parameters:
streamNumber - The stream number
Returns:
This MessageInfo
Throws:
IllegalArgumentException - If the streamNumber is negative or greater than 65536

timeToLive

public abstract long timeToLive()
The time period that the sending side may expire the message if it has not been sent, or 0 to indicate that no timeout should occur. This value is only applicable for messages being sent, it has no meaning for received messages.

Returns:
The time period in milliseconds, or 0

timeToLive

public abstract MessageInfo timeToLive(long millis)
Sets the time period that the sending side may expire the message if it has not been sent.

Parameters:
millis - The time period in milliseconds, or 0 to indicate that no timeout should occur
Returns:
This MessageInfo
See Also:
timeToLive()

JavaTM SCTP API
DRAFT ea-b11