- All Implemented Interfaces:
Closeable
,AutoCloseable
,Channel
,InterruptibleChannel
public abstract class SctpChannel extends AbstractSelectableChannel
An SCTP channel can only control one SCTP association.
An SCTPChannel
is created by invoking one of the
open
methods of this class. A newly-created channel is open but
not yet connected, that is, there is no association setup with a remote peer.
An attempt to invoke an I/O operation upon an unconnected
channel will cause a NotYetConnectedException
to be
thrown. An association can be setup by connecting the channel using one of
its connect
methods. Once connected, the channel remains
connected until it is closed. Whether or not a channel is connected may be
determined by invoking getRemoteAddresses
.
SCTP channels support non-blocking connection: A
channel may be created and the process of establishing the link to
the remote socket may be initiated via the connect
method
for later completion by the finishConnect
method.
Whether or not a connection operation is in progress may be determined by
invoking the isConnectionPending
method.
Socket options are configured using the
setOption
method. An SCTP
channel support the following options:
Additional (implementation specific) options may also be supported. The list of options supported is obtained by invoking the
Option Name Description SCTP_DISABLE_FRAGMENTS
Enables or disables message fragmentation SCTP_EXPLICIT_COMPLETE
Enables or disables explicit message completion SCTP_FRAGMENT_INTERLEAVE
Controls how the presentation of messages occur for the message receiver SCTP_INIT_MAXSTREAMS
The maximum number of streams requested by the local endpoint during association initialization SCTP_NODELAY
Enables or disable a Nagle-like algorithm SCTP_PRIMARY_ADDR
Requests that the local SCTP stack use the given peer address as the association primary SCTP_SET_PEER_PRIMARY_ADDR
Requests that the peer mark the enclosed address as the association primary SO_SNDBUF
The size of the socket send buffer SO_RCVBUF
The size of the socket receive buffer SO_LINGER
Linger on close if data is present (when configured in blocking mode only)
supportedOptions
method.
SCTP channels are safe for use by multiple concurrent threads.
They support concurrent reading and writing, though at most one thread may be
reading and at most one thread may be writing at any given time. The
connect
and finishConnect
methods are mutually synchronized against each other, and
an attempt to initiate a send or receive operation while an invocation of one
of these methods is in progress will block until that invocation is complete.
- Since:
- 1.7
-
Constructor Summary
Constructors Modifier Constructor Description protected
SctpChannel(SelectorProvider provider)
Initializes a new instance of this class. -
Method Summary
Modifier and Type Method Description abstract Association
association()
Returns the association on this channel's socket.abstract SctpChannel
bind(SocketAddress local)
Binds the channel's socket to a local address.abstract SctpChannel
bindAddress(InetAddress address)
Adds the given address to the bound addresses for the channel's socket.abstract boolean
connect(SocketAddress remote)
Connects this channel's socket.abstract boolean
connect(SocketAddress remote, int maxOutStreams, int maxInStreams)
Connects this channel's socket.abstract boolean
finishConnect()
Finishes the process of connecting an SCTP channel.abstract Set<SocketAddress>
getAllLocalAddresses()
Returns all of the socket addresses to which this channel's socket is bound.abstract <T> T
getOption(SctpSocketOption<T> name)
Returns the value of a socket option.abstract Set<SocketAddress>
getRemoteAddresses()
Returns all of the remote addresses to which this channel's socket is connected.abstract boolean
isConnectionPending()
Tells whether or not a connection operation is in progress on this channel.static SctpChannel
open()
Opens an SCTP channel.static SctpChannel
open(SocketAddress remote, int maxOutStreams, int maxInStreams)
Opens an SCTP channel and connects it to a remote address.abstract <T> MessageInfo
receive(ByteBuffer dst, T attachment, NotificationHandler<T> handler)
Receives a message into the given buffer and/or handles a notification.abstract int
send(ByteBuffer src, MessageInfo messageInfo)
Sends a message via this channel.abstract <T> SctpChannel
setOption(SctpSocketOption<T> name, T value)
Sets the value of a socket option.abstract SctpChannel
shutdown()
Shutdown a connection without closing the channel.abstract Set<SctpSocketOption<?>>
supportedOptions()
Returns a set of the socket options supported by this channel.abstract SctpChannel
unbindAddress(InetAddress address)
Removes the given address from the bound addresses for the channel's socket.int
validOps()
Returns an operation set identifying this channel's supported operations.Methods declared in class java.nio.channels.spi.AbstractSelectableChannel
configureBlocking, implCloseChannel, implCloseSelectableChannel, implConfigureBlocking, provider, register
Methods declared in class java.nio.channels.SelectableChannel
blockingLock, isBlocking, isRegistered, keyFor, register
Methods declared in class java.nio.channels.spi.AbstractInterruptibleChannel
begin, close, end
-
Constructor Details
-
SctpChannel
Initializes a new instance of this class.- Parameters:
provider
- The selector provider for this channel
-
-
Method Details
-
open
Opens an SCTP channel.The new channel is unbound and unconnected.
- Returns:
- A new SCTP channel
- Throws:
UnsupportedOperationException
- If the SCTP protocol is not supportedIOException
- If an I/O error occurs
-
open
public static SctpChannel open(SocketAddress remote, int maxOutStreams, int maxInStreams) throws IOExceptionOpens an SCTP channel and connects it to a remote address.This is a convenience method and is equivalent to evaluating the following expression:
open().connect(remote, maxOutStreams, maxInStreams);
- Parameters:
remote
- The remote address to which the new channel is to be connectedmaxOutStreams
- The number of streams that the application wishes to be able to send to. Must be non negative and no larger than65536
.0
to use the endpoints default value.maxInStreams
- The maximum number of inbound streams the application is prepared to support. Must be non negative and no larger than65536
.0
to use the endpoints default value.- Returns:
- A new SCTP channel connected to the given address
- Throws:
AsynchronousCloseException
- If another thread closes this channel while the connect operation is in progressClosedByInterruptException
- If another thread interrupts the current thread while the connect operation is in progress, thereby closing the channel and setting the current thread's interrupt statusUnresolvedAddressException
- If the given remote address is not fully resolvedUnsupportedAddressTypeException
- If the type of the given remote address is not supportedSecurityException
- If a security manager has been installed and it does not permit access to the given remote peerUnsupportedOperationException
- If the SCTP protocol is not supportedIOException
- If some other I/O error occurs
-
association
Returns the association on this channel's socket.- Returns:
- the association, or
null
if the channel's socket is not connected. - Throws:
ClosedChannelException
- If the channel is closedIOException
- If some other I/O error occurs
-
bind
Binds the channel's socket to a local address.This method is used to establish a relationship between the socket and the local addresses. Once a relationship is established then the socket remains bound until the channel is closed. This relationship may not necesssarily be with the address
local
as it may be removed byunbindAddress
, but there will always be at least one local address bound to the channel's socket once an invocation of this method successfully completes.Once the channel's socket has been successfully bound to a specific address, that is not automatically assigned, more addresses may be bound to it using
bindAddress
, or removed usingunbindAddress
.- Parameters:
local
- The local address to bind the socket, ornull
to bind the socket to an automatically assigned socket address- Returns:
- This channel
- Throws:
AlreadyConnectedException
- If this channel is already connectedClosedChannelException
- If this channel is closedConnectionPendingException
- If a non-blocking connection operation is already in progress on this channelAlreadyBoundException
- If this channel is already boundUnsupportedAddressTypeException
- If the type of the given address is not supportedIOException
- If some other I/O error occursSecurityException
- If a security manager has been installed and itscheckListen
method denies the operation
-
bindAddress
Adds the given address to the bound addresses for the channel's socket.The given address must not be the
wildcard
address. The channel must be first bound usingbind
before invoking this method, otherwiseNotYetBoundException
is thrown. Thebind
method takes aSocketAddress
as its argument which typically contains a port number as well as an address. Addresses subquently bound using this method are simply addresses as the SCTP port number remains the same for the lifetime of the channel.Adding addresses to a connected association is optional functionality. If the endpoint supports dynamic address reconfiguration then it may send the appropriate message to the peer to change the peers address lists.
- Parameters:
address
- The address to add to the bound addresses for the socket- Returns:
- This channel
- Throws:
ClosedChannelException
- If this channel is closedConnectionPendingException
- If a non-blocking connection operation is already in progress on this channelNotYetBoundException
- If this channel is not yet boundAlreadyBoundException
- If this channel is already bound to the given addressIllegalArgumentException
- If address isnull
or thewildcard
addressIOException
- If some other I/O error occurs
-
unbindAddress
Removes the given address from the bound addresses for the channel's socket.The given address must not be the
wildcard
address. The channel must be first bound usingbind
before invoking this method, otherwiseNotYetBoundException
is thrown. If this method is invoked on a channel that does not haveaddress
as one of its bound addresses or that has only one local address bound to it, then this method throwsIllegalUnbindException
. The initial address that the channel's socket is bound to usingbind
may be removed from the bound addresses for the channel's socket.Removing addresses from a connected association is optional functionality. If the endpoint supports dynamic address reconfiguration then it may send the appropriate message to the peer to change the peers address lists.
- Parameters:
address
- The address to remove from the bound addresses for the socket- Returns:
- This channel
- Throws:
ClosedChannelException
- If this channel is closedConnectionPendingException
- If a non-blocking connection operation is already in progress on this channelNotYetBoundException
- If this channel is not yet boundIllegalArgumentException
- If address isnull
or thewildcard
addressIllegalUnbindException
- Ifaddress
is not bound to the channel's socket. or the channel has only one address bound to itIOException
- If some other I/O error occurs
-
connect
Connects this channel's socket.If this channel is in non-blocking mode then an invocation of this method initiates a non-blocking connection operation. If the connection is established immediately, as can happen with a local connection, then this method returns
true
. Otherwise this method returnsfalse
and the connection operation must later be completed by invoking thefinishConnect
method.If this channel is in blocking mode then an invocation of this method will block until the connection is established or an I/O error occurs.
If a security manager has been installed then this method verifies that its
checkConnect
method permits connecting to the address and port number of the given remote peer.This method may be invoked at any time. If a
send
orreceive
operation upon this channel is invoked while an invocation of this method is in progress then that operation will first block until this invocation is complete. If a connection attempt is initiated but fails, that is, if an invocation of this method throws a checked exception, then the channel will be closed.- Parameters:
remote
- The remote peer to which this channel is to be connected- Returns:
true
if a connection was established,false
if this channel is in non-blocking mode and the connection operation is in progress- Throws:
AlreadyConnectedException
- If this channel is already connectedConnectionPendingException
- If a non-blocking connection operation is already in progress on this channelClosedChannelException
- If this channel is closedAsynchronousCloseException
- If another thread closes this channel while the connect operation is in progressClosedByInterruptException
- If another thread interrupts the current thread while the connect operation is in progress, thereby closing the channel and setting the current thread's interrupt statusUnresolvedAddressException
- If the given remote address is not fully resolvedUnsupportedAddressTypeException
- If the type of the given remote address is not supportedSecurityException
- If a security manager has been installed and it does not permit access to the given remote peerIOException
- If some other I/O error occurs
-
connect
public abstract boolean connect(SocketAddress remote, int maxOutStreams, int maxInStreams) throws IOExceptionConnects this channel's socket.This is a convience method and is equivalent to evaluating the following expression:
setOption(SctpStandardSocketOptions.SCTP_INIT_MAXSTREAMS, SctpStandardSocketOption.InitMaxStreams.create(maxInStreams, maxOutStreams)) .connect(remote);
The
maxOutStreams
andmaxInStreams
parameters represent the maximum number of streams that the application wishes to be able to send to and receive from. They are negotiated with the remote peer and may be limited by the operating system.- Parameters:
remote
- The remote peer to which this channel is to be connectedmaxOutStreams
- Must be non negative and no larger than65536
.0
to use the endpoints default value.maxInStreams
- Must be non negative and no larger than65536
.0
to use the endpoints default value.- Returns:
true
if a connection was established,false
if this channel is in non-blocking mode and the connection operation is in progress- Throws:
AlreadyConnectedException
- If this channel is already connectedConnectionPendingException
- If a non-blocking connection operation is already in progress on this channelClosedChannelException
- If this channel is closedAsynchronousCloseException
- If another thread closes this channel while the connect operation is in progressClosedByInterruptException
- If another thread interrupts the current thread while the connect operation is in progress, thereby closing the channel and setting the current thread's interrupt statusUnresolvedAddressException
- If the given remote address is not fully resolvedUnsupportedAddressTypeException
- If the type of the given remote address is not supportedSecurityException
- If a security manager has been installed and it does not permit access to the given remote peerIOException
- If some other I/O error occurs
-
isConnectionPending
public abstract boolean isConnectionPending()Tells whether or not a connection operation is in progress on this channel.- Returns:
true
if, and only if, a connection operation has been initiated on this channel but not yet completed by invoking thefinishConnect()
method
-
finishConnect
Finishes the process of connecting an SCTP channel.A non-blocking connection operation is initiated by placing a socket channel in non-blocking mode and then invoking one of its
connect
methods. Once the connection is established, or the attempt has failed, the channel will become connectable and this method may be invoked to complete the connection sequence. If the connection operation failed then invoking this method will cause an appropriateIOException
to be thrown.If this channel is already connected then this method will not block and will immediately return
true
. If this channel is in non-blocking mode then this method will returnfalse
if the connection process is not yet complete. If this channel is in blocking mode then this method will block until the connection either completes or fails, and will always either returntrue
or throw a checked exception describing the failure.This method may be invoked at any time. If a
send
orreceive
operation upon this channel is invoked while an invocation of this method is in progress then that operation will first block until this invocation is complete. If a connection attempt fails, that is, if an invocation of this method throws a checked exception, then the channel will be closed.- Returns:
true
if, and only if, this channel's socket is now connected- Throws:
NoConnectionPendingException
- If this channel is not connected and a connection operation has not been initiatedClosedChannelException
- If this channel is closedAsynchronousCloseException
- If another thread closes this channel while the connect operation is in progressClosedByInterruptException
- If another thread interrupts the current thread while the connect operation is in progress, thereby closing the channel and setting the current thread's interrupt statusIOException
- If some other I/O error occurs
-
getAllLocalAddresses
Returns all of the socket addresses to which this channel's socket is bound.- Returns:
- All the socket addresses that this channel's socket is
bound to, or an empty
Set
if the channel's socket is not bound - Throws:
ClosedChannelException
- If the channel is closedIOException
- If an I/O error occurs
-
getRemoteAddresses
Returns all of the remote addresses to which this channel's socket is connected.If the channel is connected to a remote peer that is bound to multiple addresses then it is these addresses that the channel's socket is connected.
- Returns:
- All of the remote addresses to which this channel's socket
is connected, or an empty
Set
if the channel's socket is not connected - Throws:
ClosedChannelException
- If the channel is closedIOException
- If an I/O error occurs
-
shutdown
Shutdown a connection without closing the channel.Sends a shutdown command to the remote peer, effectively preventing any new data from being written to the socket by either peer. Further sends will throw
ClosedChannelException
. The channel remains open to allow the for any data (and notifications) to be received that may have been sent by the peer before it received the shutdown command. If the channel is already shutdown then invoking this method has no effect.- Returns:
- This channel
- Throws:
NotYetConnectedException
- If this channel is not yet connectedClosedChannelException
- If this channel is closedIOException
- If some other I/O error occurs
-
getOption
Returns the value of a socket option.- Type Parameters:
T
- The type of the socket option value- Parameters:
name
- The socket option- Returns:
- The value of the socket option. A value of
null
may be a valid value for some socket options. - Throws:
UnsupportedOperationException
- If the socket option is not supported by this channelClosedChannelException
- If this channel is closedIOException
- If an I/O error occurs- See Also:
SctpStandardSocketOptions
-
setOption
Sets the value of a socket option.- Type Parameters:
T
- The type of the socket option value- Parameters:
name
- The socket optionvalue
- The value of the socket option. A value ofnull
may be a valid value for some socket options.- Returns:
- This channel
- Throws:
UnsupportedOperationException
- If the socket option is not supported by this channelIllegalArgumentException
- If the value is not a valid value for this socket optionClosedChannelException
- If this channel is closedIOException
- If an I/O error occurs- See Also:
SctpStandardSocketOptions
-
supportedOptions
Returns a set of the socket options supported by this channel.This method will continue to return the set of options even after the channel has been closed.
- Returns:
- A set of the socket options supported by this channel
-
validOps
public final int validOps()Returns an operation set identifying this channel's supported operations.SCTP channels support connecting, reading, and writing, so this method returns
(
SelectionKey.OP_CONNECT
|
SelectionKey.OP_READ
|
SelectionKey.OP_WRITE
)
.- Specified by:
validOps
in classSelectableChannel
- Returns:
- The valid-operation set
-
receive
public abstract <T> MessageInfo receive(ByteBuffer dst, T attachment, NotificationHandler<T> handler) throws IOExceptionReceives a message into the given buffer and/or handles a notification.If a message or notification is immediately available, or if this channel is in blocking mode and one eventually becomes available, then the message or notification is returned or handled, respectively. If this channel is in non-blocking mode and a message or notification is not immediately available then this method immediately returns
null
.If this method receives a message it is copied into the given byte buffer. The message is transferred into the given byte buffer starting at its current position and the buffers position is incremented by the number of bytes read. If there are fewer bytes remaining in the buffer than are required to hold the message, or the underlying input buffer does not contain the complete message, then an invocation of
isComplete
on the returnedMessageInfo
will returnfalse
, and more invocations of this method will be necessary to completely consume the messgae. Only one message at a time will be partially delivered in any stream. The socket optionSCTP_FRAGMENT_INTERLEAVE
controls various aspects of what interlacing of messages occurs.If this method receives a notification then the appropriate method of the given handler, if there is one, is invoked. If the handler returns
CONTINUE
then this method will try to receive another message/notification, otherwise, ifRETURN
is returned this method will returnnull
. If an uncaught exception is thrown by the handler it will be propagated up the stack through this method.This method may be invoked at any time. If another thread has already initiated a receive operation upon this channel, then an invocation of this method will block until the first operation is complete. The given handler is invoked without holding any locks used to enforce the above synchronization policy, that way handlers will not stall other threads from receiving. A handler should not invoke the
receive
method of this channel, if it does anIllegalReceiveException
will be thrown.- Type Parameters:
T
- The type of the attachment- Parameters:
dst
- The buffer into which message bytes are to be transferredattachment
- The object to attach to the receive operation; can benull
handler
- A handler to handle notifications from the SCTP stack, ornull
to ignore any notifications.- Returns:
- The
MessageInfo
,null
if this channel is in non-blocking mode and no messages are immediately available or the notification handler returnsRETURN
after handling a notification - Throws:
ClosedChannelException
- If this channel is closedAsynchronousCloseException
- If another thread closes this channel while the read operation is in progressClosedByInterruptException
- If another thread interrupts the current thread while the read operation is in progress, thereby closing the channel and setting the current thread's interrupt statusNotYetConnectedException
- If this channel is not yet connectedIllegalReceiveException
- If the given handler invokes thereceive
method of this channelIOException
- If some other I/O error occurs
-
send
Sends a message via this channel.If this channel is in non-blocking mode and there is sufficient room in the underlying output buffer, or if this channel is in blocking mode and sufficient room becomes available, then the remaining bytes in the given byte buffer are transmitted as a single message. Sending a message is atomic unless explicit message completion
SCTP_EXPLICIT_COMPLETE
socket option is enabled on this channel's socket.The message is transferred from the byte buffer as if by a regular
write
operation.The bytes will be written to the stream number that is specified by
streamNumber
in the givenmessageInfo
.This method may be invoked at any time. If another thread has already initiated a send operation upon this channel, then an invocation of this method will block until the first operation is complete.
- Parameters:
src
- The buffer containing the message to be sentmessageInfo
- Ancillary data about the message to be sent- Returns:
- The number of bytes sent, which will be either the number of bytes that were remaining in the messages buffer when this method was invoked or, if this channel is non-blocking, may be zero if there was insufficient room for the message in the underlying output buffer
- Throws:
InvalidStreamException
- IfstreamNumner
is negative or greater than or equal to the maximum number of outgoing streamsClosedChannelException
- If this channel is closedAsynchronousCloseException
- If another thread closes this channel while the read operation is in progressClosedByInterruptException
- If another thread interrupts the current thread while the read operation is in progress, thereby closing the channel and setting the current thread's interrupt statusNotYetConnectedException
- If this channel is not yet connectedIOException
- If some other I/O error occurs
-