org.simpleframework.transport
Interface Channel

All Known Implementing Classes:

TransportChannel

public interface Channel

The Channel interface represents a connected channel through which data can be sent and received. Typically a channel will have a connected TCP socket, which can be used to determine when the channel is read ready, and write ready. A channel can also contain a bag of attributes used to describe the connection.

Reading and writing to a channel is performed using two special interfaces. The first is the Cursor object which is used to read data from the channel in a non-blocking manner. This can also be used to reset data if it has read too much. To write the Sender can be used, this provides a blocking interface much like a conventional output stream.

Author:

Niall Gallagher

Method Summary

void	close() Because the channel represents a duplex means of communication there needs to be a means to close it down.
Map	getAttributes() This returns the Map of attributes used to hold connection information for the channel.
Cursor	getCursor() This provides the Cursor for this channel.
SSLEngine	getEngine() This is used to acquire the SSL engine used for security.
Sender	getSender() This provides the Sender for the channel.
SocketChannel	getSocket() This is the connected socket channel associated with this.
Trace	getTrace() This gets the Trace object associated with the channel.
boolean	isSecure() This is used to determine if the channel is secure and that data read from and data written to the request is encrypted.

Method Detail

isSecure

boolean isSecure()

This is used to determine if the channel is secure and that data read from and data written to the request is encrypted. Channels transferred over SSL are considered secure and will have this return true, otherwise it will return false.

Returns:

true if this is secure for reading and writing

getSocket

SocketChannel getSocket()

This is the connected socket channel associated with this. In order to determine if content can be read or written to or from the channel this socket can be used with a selector. This provides a means to react to I/O events as they occur rather than polling the channel which is generally less performant.

Returns:

this returns the connected socket channel

getEngine

SSLEngine getEngine()

This is used to acquire the SSL engine used for security. If the socket is connected to an SSL transport this returns an SSL engine which can be used to establish the secure connection and send and receive content over that connection. If this is null then the socket represents a normal transport.

Returns:

the SSL engine used to establish a secure transport

getTrace

Trace getTrace()

This gets the Trace object associated with the channel. The trace is used to log various events for the life of the transaction such as low level read and write events as well as milestone events and errors.

Returns:

this returns the trace associated with the socket

getCursor

Cursor getCursor()

This provides the Cursor for this channel. The cursor provides a resettable view of the input buffer and will allow the server kernel to peek into the input buffer without having to take the data from the input. This allows overflow to be pushed back on to the cursor for subsequent reads.

Returns:

this returns the input cursor for the channel

getSender

Sender getSender()

This provides the Sender for the channel. This is used to provide a blocking output mechanism for the channel. Enabling blocking reads ensures that output buffering can be limited to an extent, which ensures that memory remains low at high load periods. Writes to the sender may result in the data being copied and queued until the socket is write ready.

Returns:

this returns the output sender for this channel

getAttributes

Map getAttributes()

This returns the Map of attributes used to hold connection information for the channel. The attributes here are taken from the pipeline attributes and may contain details such as SSL certificates or other such useful information.

Returns:

returns the attributes associated with the channel

close

void close()

Because the channel represents a duplex means of communication there needs to be a means to close it down. This provides such a means. By closing the channel the cursor and sender will no longer send or recieve data to or from the network. The client will also be signaled that the connection has been severed.