org.freeswitch.esl.client.internal
Class AbstractEslClientHandler

java.lang.Object
  org.jboss.netty.channel.SimpleChannelUpstreamHandler
      org.freeswitch.esl.client.internal.AbstractEslClientHandler

All Implemented Interfaces:

ChannelHandler, ChannelUpstreamHandler

Direct Known Subclasses:

AbstractOutboundClientHandler, InboundClientHandler

public abstract class AbstractEslClientHandler
extends SimpleChannelUpstreamHandler

Specialised ChannelUpstreamHandler that implements the logic of an ESL connection that is common to both inbound and outbound clients. This handler expects to receive decoded EslMessage or EslEvent objects. The key responsibilities for this class are:

• To synthesise a synchronous command/response api. All IO operations using the underlying Netty library are intrinsically asynchronous which provides for excellent response and scalability. This class provides for a blocking wait mechanism for responses to commands issued to the server. A key assumption here is that the FreeSWITCH server will process synchronous requests in the order they are received.
• Concrete sub classes are expected to 'terminate' the Netty IO processing pipeline (ie be the 'last' handler).

Note: implementation requirement is that an ExecutionHandler is placed in the processing pipeline prior to this handler. This will ensure that each incoming message is processed in its own thread (although still guaranteed to be processed in the order of receipt).

Author:

david varnes

Nested Class Summary

Nested classes/interfaces inherited from interface org.jboss.netty.channel.ChannelHandler

ChannelHandler.Sharable

Field Summary

static String	LINE_TERMINATOR
static String	MESSAGE_TERMINATOR

Constructor Summary

AbstractEslClientHandler()

Method Summary

void	messageReceived(ChannelHandlerContext ctx, MessageEvent e)
String	sendAsyncCommand(Channel channel, String command) Returns the Job UUID of that the response event will have.
EslMessage	sendSyncMultiLineCommand(Channel channel, List<String> commandLines) Synthesise a synchronous command/response by creating a callback object which is placed in queue and blocks waiting for another IO thread to process an incoming EslMessage and attach it to the callback.
EslMessage	sendSyncSingleLineCommand(Channel channel, String command) Synthesise a synchronous command/response by creating a callback object which is placed in queue and blocks waiting for another IO thread to process an incoming EslMessage and attach it to the callback.

Methods inherited from class org.jboss.netty.channel.SimpleChannelUpstreamHandler

channelBound, channelClosed, channelConnected, channelDisconnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, exceptionCaught, handleUpstream, writeComplete

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MESSAGE_TERMINATOR

public static final String MESSAGE_TERMINATOR

See Also:

Constant Field Values

LINE_TERMINATOR

public static final String LINE_TERMINATOR

See Also:

Constant Field Values

Constructor Detail

AbstractEslClientHandler

public AbstractEslClientHandler()

Method Detail

messageReceived

public void messageReceived(ChannelHandlerContext ctx,
                            MessageEvent e)
                     throws Exception

Overrides:

messageReceived in class SimpleChannelUpstreamHandler

Throws:

Exception

sendSyncSingleLineCommand

public EslMessage sendSyncSingleLineCommand(Channel channel,
                                            String command)

Synthesise a synchronous command/response by creating a callback object which is placed in queue and blocks waiting for another IO thread to process an incoming EslMessage and attach it to the callback.

Parameters:

channel -

command - single string to send

Returns:

the EslMessage attached to this command's callback

sendSyncMultiLineCommand

public EslMessage sendSyncMultiLineCommand(Channel channel,
                                           List<String> commandLines)

Synthesise a synchronous command/response by creating a callback object which is placed in queue and blocks waiting for another IO thread to process an incoming EslMessage and attach it to the callback.

Parameters:

channel -

command - List of command lines to send

Returns:

the EslMessage attached to this command's callback

sendAsyncCommand

public String sendAsyncCommand(Channel channel,
                               String command)

Returns the Job UUID of that the response event will have.

Parameters:

channel -

command -

Returns:

Job-UUID as a string