sunlabs.brazil.asterisk
Class AsteriskHandler

java.lang.Object
  sunlabs.brazil.template.Template
      sunlabs.brazil.asterisk.AsteriskHandler (view source)

All Implemented Interfaces:

Handler, TemplateInterface

public class AsteriskHandler
extends Template
implements Handler

Connect to asterisk manager api. There is one connection per server. This is used both to issue Commands to Asterisk via the manager interface, and to register for, and receive asynchronous event notifications.

Usage:

 <register queue=xxx key=xxx pattern=xxx [context=xxx server=xxx]>
  - register interest in a manager event (or events).  All generated events
    will be available with <dequeue name=xxx ...>, where the "name"
    parameter of the <dequeue> matches the "queue" parameter of
    <register>.
 <unregister queue=xxx key=xxx>
  - unregister interest in a previously registered event.
 <enqueue name="queue" from="my-q" ...>
  - Send an command to the manager interface. "queue" is the name
    specified in the handler "queue" parameter.  The enqueue'd data
    must have an "action" key.  The result of the command is obtained by:
    <dequeue name="my-q" ...>  where "my-q" is the "from" attribute of
    the corrosponding <enqueue>
 <amicommand server=xxx action=xxx ...>
  - A syncronous version of the <enqueue> ... <dequeue> above.
    See below for details.
 

Nested Class Summary

static class	AsteriskHandler.AmiStringMap This class is built on top of the StringMap class and adds methods for reading Asterisk ManagerInterface replies.
static class	AsteriskHandler.EventItem Keep track of an event listener entry.
static class	AsteriskHandler.Events Class to manage the set of events.

Field Summary

Fields inherited from class sunlabs.brazil.template.Template

debug

Constructor Summary

AsteriskHandler()

Method Summary

static void	addEvent(String queue, String key, String exp, String context, String serverName) Java access to adding event registrations.
boolean	init(Server server, String prefix) Remember the host, port, id, and password for an asterisk manager connection.
static int	removeEvents(String queue, String key, String exp) java access to removing event registrations.
boolean	respond(Request request) The handler only registers * servers.
void	tag_amicommand(RewriteContext hr) Issue a synchronous command to the Asterisk AMI interface.
void	tag_asterisk(RewriteContext hr) This only emits diagnostic information to stdout.
void	tag_register(RewriteContext hr) Register an event.
void	tag_unregister(RewriteContext hr) Unregister an event (or events).

Methods inherited from class sunlabs.brazil.template.Template

done, init

Methods inherited from class java.lang.Object

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

Constructor Detail

AsteriskHandler

public AsteriskHandler()

Method Detail

init

public boolean init(Server server,
                    String prefix)

Remember the host, port, id, and password for an asterisk manager connection. We don't require that the asterisk server actually be running at server startup time. We will try hard to reconnect to the server if it goes away.

queue

The name of the Q to send manager commands to using the <enqueue name="queue" ...>. If not specifies, the "host:port" combination is used.

server

The server:port to use to contact the asterisk server

userid, password

The Manager credentials

debug=true|false

turn on more diagnostics on the console, depending on the current server logging level. at "3", keep alives are logged, at "4", all events are logged, and at "5" even more stuff is logged.

keepalive=n

If set, this handler will issue a keep-alive every "n" seconds to the Asterisk Server. If the keep-alive fails, a new connection will be attempted with the Asterisk server.

retry=n

Set the number of seconds to wait before retrying a broken connection to an asterisk server (defaults to 10).

isConnected

This is set to "true" or "false" to indicate this handler's opinion as to the state of the connection to the Asterisk server.

To communicate with multiple asterisk servers, each should have their own handler instance. Servers are distinguished when sending commands to them via the "queue" parameter, which should be different for each server. Alternately, the <amicommand> server parameter (which is the same as the server queue name) may be used.

When using multiple servers, only one of the server handler configurations should be listed as a template (there can only be one template instance for a given entity) which server doesn't matter, as events get registered for all servers (the "server" attribute of the response determines where it came from). As above, commands to a server are distinquished with either the "queue" or "server" attributes, depending on whether the command Qs are used directly, or the <amicommand> template is used.

To Do
Figure out where to send unregistered events, such as "reload".

Specified by:

init in interface Handler

Parameters:

server - The HTTP server that created this Handler. Typical Handlers will use Server.props to obtain run-time configuration information.

prefix - The handlers name. The string this Handler may prepend to all of the keys that it uses to extract configuration information from Server.props. This is set (by the Server and ChainHandler) to help avoid configuration parameter namespace collisions.

Returns:

true if this Handler initialized successfully, false otherwise. If false is returned, this Handler should not be used.

respond

public boolean respond(Request request)
                throws IOException

The handler only registers * servers. No requests are handled. Use <register> in a template instead.

Specified by:

respond in interface Handler

Parameters:

request - The Request object that represents the HTTP request.

Returns:

true if the request was handled. A request was handled if a response was supplied to the client, typically by calling Request.sendResponse() or Request.sendError.

Throws:

IOException - if there was an I/O error while sending the response to the client. Typically, in that case, the Server will (try to) send an error message to the client and then close the client's connection.

The IOException should not be used to silently ignore problems such as being unable to access some server-side resource (for example getting a FileNotFoundException due to not being able to open a file). In that case, the Handler's duty is to turn that IOException into a HTTP response indicating, in this case, that a file could not be found.

tag_asterisk

public void tag_asterisk(RewriteContext hr)

This only emits diagnostic information to stdout.

tag_amicommand

public void tag_amicommand(RewriteContext hr)

Issue a synchronous command to the Asterisk AMI interface. This is a convenience for using <enqueue> and <dequeue> directly.

Attributes:

server

The Asterisk server's Q (required).

action:

The action to perform.

variable=value

one of the variables needed by the action. (There is a fixed list, See the manager docs for more detail).

timeout

The max time to wait for a response

prepend

What to prepend all the results too.

tag_register

public void tag_register(RewriteContext hr)

Register an event.

<register queue=xxx key=xxx exp=xxx [context=xxx server=xxx]>
  queue:  The Q name to send the results to.
  key:    The manager response key to match on.  Use "*" for all keys.
  exp:  A regular expression that matches a key value
  context: If specified, only events with this context are considered. 
  server: If specified, only events from this server are considered. 
        The server matches the "Server" item in the event, and is the server
  name, followed by a ":", then the port number (e.g. pbx.com:5038).
 

addEvent

public static void addEvent(String queue,
                            String key,
                            String exp,
                            String context,
                            String serverName)

Java access to adding event registrations.

tag_unregister

public void tag_unregister(RewriteContext hr)

Unregister an event (or events). Match on "queue", "exp" and "key"

removeEvents

public static int removeEvents(String queue,
                               String key,
                               String exp)

java access to removing event registrations.