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layout: page
title: Tutorial
permalink: /tutorial/
---
This page provides a basic introduction and some sample code for The
FastAGI Protocol, The Manager API, and The Live API. If you
don't see a tutorial for the part of Asterisk-Java that you're
interested in, please scroll down to make sure it isn't further down the
page, or send us more examples that you would like to see included.
The FastAGI Protocol
--------------------
The easiest way to interact with Asterisk from Java applications is via
the FastAGI protocol. AGI scripts can handle either incoming calls or
calls originated via the Manager API (see below for an example on how to
use Asterisk-Java to originate a call from your Java application).
The AGI (Asterisk Gateway Interface) facility allows you to launch
scripts, from the Asterisk dial plan. Traditionally communication
between the scripts and Asterisk was via standard input and standard
output and scripts had to run on the same machine as Asterisk. Due to
the large amount of time a Java Virtual Machine needs for startup and
the discomfort of having to install a Java environment on the PBX
box(es) Java has not been the language of choice for writing AGI
scripts.
These drawbacks have been addressed by the addition of FastAGI to
Asterisk. FastAGI is basically AGI over TCP/IP socket connections
instead of using standard input and standard output as communication
medium.
Using FastAGI you can run a Java application (on the same machine that
runs Asterisk or on a separate machine) that is only started once and
serves AGI scripts until it is shut down. Combined with Java's
multithreading support you can build pretty fast AGI scripts using this
protocol.
Asterisk-Java helps you with running your Java based AGI scripts by
providing a container that receives connections from the Asterisk
server, parses the request and calls your scripts mapped to the called
URL.
### Hello AGI!
To write your own AGI scripts you must implement the AgiScript
interface. You can do so by simply extending BaseAgiScript that provides
some convenience methods that further simplify that task.
A simple AgiScript might look as follows:
import org.asteriskjava.fastagi.AgiChannel;
import org.asteriskjava.fastagi.AgiException;
import org.asteriskjava.fastagi.AgiRequest;
import org.asteriskjava.fastagi.BaseAgiScript;
public class HelloAgiScript extends BaseAgiScript
{
public void service(AgiRequest request, AgiChannel channel)
throws AgiException
{
// Answer the channel...
answer();
// ...say hello...
streamFile("welcome");
// ...and hangup.
hangup();
}
}
Put this Java source file into a directory of your choice, add the
`asterisk-java.jar` and compile it:
$ javac -cp asterisk-java.jar HelloAgiScript.java
$
Next you have to add a call to your script to your dialplan in Asterisk.
You might want to add an extension 1300 to the default section of your
`extensions.conf`:
[default]
...
exten => 1300,1,Agi(agi://localhost/hello.agi)
Replace localhost with the hostname of the machine that runs
Asterisk-Java.
Be sure to reload Asterisk for this change to take effect. You can do so
by executing `extensions reload` on the Asterisk CLI.
Now you must map the script name `hello.agi` to the HelloAgiScript we
just created. By default this is done in a properties file called
`fastagi-mapping.properties` that must be on the classpath when we start
the AgiServer. In this case it looks like:
hello.agi = HelloAgiScript
Your directory should now contain the following files:
$ ls -l
-rw-r--r-- 1 srt srt 163689 2005-03-11 22:07 asterisk-java.jar
-rw-r--r-- 1 srt srt 26 2005-03-11 20:50 fastagi-mapping.properties
-rw-r--r-- 1 srt srt 624 2005-03-11 22:07 HelloAgiScript.class
-rw-r--r-- 1 srt srt 438 2005-03-11 20:50 HelloAgiScript.java
Finally we start the AgiServer:
$ java -jar asterisk-java.jar
For Asterisk-Java 0.3.1 and earlier you would use
$ java -cp asterisk-java.jar:. org.asteriskjava.fastagi.DefaultAgiServer
or on Windows:
$ java -cp asterisk-java.jar;. org.asteriskjava.fastagi.DefaultAgiServer
You should see some logging output indicating that the AgiServer has
been successfully started and is listening for incoming connections:
Mar 11, 2005 10:20:12 PM org.asteriskjava.fastagi.DefaultAgiServer run
INFO: Thread pool started.
Mar 11, 2005 10:20:12 PM org.asteriskjava.fastagi.DefaultAgiServer run
INFO: Listening on *:4573.
When you call extension 1300 you will see the AGI script being launched:
Mar 11, 2005 10:22:47 PM org.asteriskjava.fastagi.DefaultAgiServer run
INFO: Received connection.
Mar 11, 2005 10:22:47 PM org.asteriskjava.fastagi.AgiConnectionHandler run
INFO: Begin AgiScript HelloAgiScript on AgiServer-TaskThread-0
Mar 11, 2005 10:22:48 PM org.asteriskjava.fastagi.AGIConnectionHandler run
INFO: End AgiScript HelloAgiScript on AgiServer-TaskThread-0
### Extending the Example
Have a look at the documentation of
[BaseAgiScript](#apidocsorgasteriskjavafastagiBaseAgiScript.html) there
you will find additional methods that you can use for your own scripts.
If you want to use commands that do not yet have a corresponding method
in BaseAgiScript or if you want to extend the FastAGI protocol by adding
your own commands you can also use the
[channel](#apidocsorgasteriskjavafastagiAgiChannel.html).sendCommand([AgiCommand](#apidocsorgasteriskjavafastagicommandAgiCommand.html))
method to send arbitrary commands.
You can pass parameters to your scripts by including them in the URL
used with the AGI command. These parameters can be read by the
getParameter(String) and getParameterValues(String) methods in
[AgiRequest](#apidocsorgasteriskjavafastagiAgiRequest.html).
If you want to pass a parameter named user with a value of "john" to
your script called hello.agi running on localhost your call to the AGI
application looks like this:
exten => 1300,1,Agi(agi://localhost/hello.agi?user=john)
You can also pass multiple parameters. Parameters containing special
characters must be URL encoded.
If you are about to write more complex scripts please note that your
AgiScript must be thread-safe. Only one instance will be used to serve
all requests. This is kind of similar to the constraints a servlet
engine places on the implementation of servlets.
### Configuration
You can tune the DefaultAgiServer by setting two properties: The
bindPort and the poolSize.
The bindPort determines the TCP port the server will listen on. By
default this is the FastAGI port 4573. If you change it make sure to
include the new port in the URLs used in `extensions.conf`. When using
bindPort 1234 your `extensions.conf` will contain:
exten => 1300,1,Agi(agi://localhost:1234/hello.agi)
To understand the poolSize property you need to know that the
DefaultAgiServer uses a fixed size thread pool to serve your AgiScripts.
The poolSize determines how many threads are spawned at startup and thus
limits the number of AgiScripts that can run at the same time. So you
should set the poolSize to at least the number of concurrent calls the
AgiServer should be able to handle. The default value is 10.
These configuration properties can be set by providing a
`fastagi.properties` file on the classpath.
This might look like:
bindPort = 1234
poolSize = 20
The Manager API
---------------
The Manager API is the other way for remote interaction with an Asterisk
server. In contrast to the FastAGI protocol Asterisk does not explicitly
pass control to your application when using the Manager API but allows
you to query and change its state at any time.
The Manager API is made up of three concepts: Actions, Responses and
Events. Actions can be sent to Asterisk and instruct it to do someting.
For example your application can send an Action to Asterisk requesting
it to dial a number and direct the dialed party to one of your phones.
In reply to an Action Asterisk sends a Reply that contains the results
of the operation performed.
Events are sent by Asterisk without a direct relation to the Actions
your application is sending. Events inform you about the relevant
changes in Asterisk's state. For example Events are used to inform your
application about incoming calls or users joining or leaving MeetMe
conference rooms.
The connection to the Asterisk server via Manager API occurs over TCP/IP
usually on the default port 5038.
To enable the Manager API on Asterisk you must edit your `manager.conf`
configuration file and restart Asterisk. The `manager.conf` also
contains constraints on the range of IP addresses that are allowed to
connect and username and passwords for authentication. A sample might
look like:
[general]
enabled = yes
port = 5038
bindaddr = 0.0.0.0
[manager]
secret=pa55w0rd
permit=0.0.0.0/0.0.0.0
read=all
write=all
This will enable the Manager AP, allow access from any IP address using
the username "manager" and the password "pa55w0rd".
### Hello Manager!
Assume we have a phone connected via SIP that is available at SIP/john
and we want to initiate a call from that phone to extension 1300 in the
default context.
We have to obtain a
[ManagerConnection](#apidocsorgasteriskjavamanagerManagerConnection.html)
providing the hostname Asterisk is running on and the username and
password as configured in `manager.conf`. Next we log in and send an
[OriginateAction](#apidocsorgasteriskjavamanageractionOriginateAction.html)
and finally we disconnect.
An example that does this is shown below.
import java.io.IOException;
import org.asteriskjava.manager.AuthenticationFailedException;
import org.asteriskjava.manager.ManagerConnection;
import org.asteriskjava.manager.ManagerConnectionFactory;
import org.asteriskjava.manager.TimeoutException;
import org.asteriskjava.manager.action.OriginateAction;
import org.asteriskjava.manager.response.ManagerResponse;
public class HelloManager
{
private ManagerConnection managerConnection;
public HelloManager() throws IOException
{
ManagerConnectionFactory factory = new ManagerConnectionFactory(
"localhost", "manager", "pa55w0rd");
this.managerConnection = factory.createManagerConnection();
}
public void run() throws IOException, AuthenticationFailedException,
TimeoutException
{
OriginateAction originateAction;
ManagerResponse originateResponse;
originateAction = new OriginateAction();
originateAction.setChannel("SIP/John");
originateAction.setContext("default");
originateAction.setExten("1300");
originateAction.setPriority(new Integer(1));
originateAction.setTimeout(new Integer(30000));
// connect to Asterisk and log in
managerConnection.login();
// send the originate action and wait for a maximum of 30 seconds for Asterisk
// to send a reply
originateResponse = managerConnection.sendAction(originateAction, 30000);
// print out whether the originate succeeded or not
System.out.println(originateResponse.getResponse());
// and finally log off and disconnect
managerConnection.logoff();
}
public static void main(String[] args) throws Exception
{
HelloManager helloManager;
helloManager = new HelloManager();
helloManager.run();
}
}
A list of the other
[Actions](#apidocsorgasteriskjavamanageractionpackage-summary.html)
provided by the Manager API is available in the
[javadocs](#apidocsindex.html).
### Hello Events!
To receive events from Asterisk you have to implement the
[ManagerEventListener](#apidocsorgasteriskjavamanagerManagerEventListener.html)
interface and add it to the
[ManagerConnection](#apidocsorgasteriskjavamanagerManagerConnection.html).
The following code shows a simple example of how to do this:
import java.io.IOException;
import org.asteriskjava.manager.AuthenticationFailedException;
import org.asteriskjava.manager.ManagerConnection;
import org.asteriskjava.manager.ManagerConnectionFactory;
import org.asteriskjava.manager.ManagerEventListener;
import org.asteriskjava.manager.TimeoutException;
import org.asteriskjava.manager.action.StatusAction;
import org.asteriskjava.manager.event.ManagerEvent;
public class HelloEvents implements ManagerEventListener
{
private ManagerConnection managerConnection;
public HelloEvents() throws IOException
{
ManagerConnectionFactory factory = new ManagerConnectionFactory(
"localhost", "manager", "pa55w0rd");
this.managerConnection = factory.createManagerConnection();
}
public void run() throws IOException, AuthenticationFailedException,
TimeoutException, InterruptedException
{
// register for events
managerConnection.addEventListener(this);
// connect to Asterisk and log in
managerConnection.login();
// request channel state
managerConnection.sendAction(new StatusAction());
// wait 10 seconds for events to come in
Thread.sleep(10000);
// and finally log off and disconnect
managerConnection.logoff();
}
public void onManagerEvent(ManagerEvent event)
{
// just print received events
System.out.println(event);
}
public static void main(String[] args) throws Exception
{
HelloEvents helloEvents;
helloEvents = new HelloEvents();
helloEvents.run();
}
}
A list of the other Events povided by the Manager API is available in the javadocs.
The Live API
------------
The live API is built on top of the Manager API and provides additional
abstraction. Instead of directly using actions and events to interact
with Asterisk you can use active domain objects (live objects) that
represent Asterisk concepts like a channel or an extension. The behavior
of live objects follows the pattern of the [JavaBeans
specification](http://java.sun.com/products/javabeans/reference/api/index.html)
by Sun.
To get started, have a look at the the [live
package](#apidocsorgasteriskjavalivepackage-summary.html) in the
[javadocs](#apidocsindex.html), especially the interfaces for
[AsteriskServer](#apidocsorgasteriskjavaliveAsteriskServer.html),
[AsteriskChannel](#apidocsorgasteriskjavaliveAsteriskChannel.html), and
[AsteriskQueue](#apidocsorgasteriskjavaliveAsteriskQueue.html).
Asterisk-Java provides implementations for these interfaces, such as
[DefaultAsteriskServer](#apidocsorgasteriskjavaliveDefaultAsteriskServer.html)
for [AsteriskServer](#apidocsorgasteriskjavaliveAsteriskServer.html).
DefaultAsteriskServer, in turn, relies on other implementation classes
provided.
### HelloLive
To run commands using the live API, you need to create an AsteriskServer
using the DefaultAsteriskServer implementation. Alternatively, if you
already have a manager connection (see "The Manager API" above), you can
pass that to the DefaultAsteriskServer. Once connected, this sample
program prints all channels, queues, and meet me objects. In a real
project, you will probably do this at the start, and perhaps perform
some actions based on the current state of Asterisk. Continue below to
see how to use events in the live package.
The following code shows a simple example of how to connect to Asterisk
using the live API:
import org.asteriskjava.live.AsteriskServer;
import org.asteriskjava.live.AsteriskChannel;
import org.asteriskjava.live.AsteriskQueue;
import org.asteriskjava.live.MeetMeRoom;
import org.asteriskjava.live.DefaultAsteriskServer;
import org.asteriskjava.live.ManagerCommunicationException;
public class HelloLive
{
private AsteriskServer asteriskServer;
public HelloLive()
{
asteriskServer = new DefaultAsteriskServer("localhost", "manager", "pa55w0rd");
}
public void run() throws ManagerCommunicationException
{
for (AsteriskChannel asteriskChannel : asteriskServer.getChannels())
{
System.out.println(asteriskChannel);
}
for (AsteriskQueue asteriskQueue : asteriskServer.getQueues())
{
System.out.println(asteriskQueue);
}
for (MeetMeRoom meetMeRoom : asteriskServer.getMeetMeRooms())
{
System.out.println(meetMeRoom);
}
}
public static void main(String[] args) throws Exception
{
HelloLive helloLive = new HelloLive();
helloLive.run();
}
}
### HelloLiveEvents
To process events using the live API, you need to implement an
[AsteriskServerListener](#apidocsorgasteriskjavaliveAsteriskServerListener.html).
Once you have a class that implements that interface, you can add it via
the DefaultAsteriskServer in order to hear about new channels.
The following code snippet shows a simple example of how to listen for
new channels or meet me users:
import org.asteriskjava.live.AsteriskChannel;
import org.asteriskjava.live.AsteriskServer;
import org.asteriskjava.live.AsteriskServerListener;
import org.asteriskjava.live.DefaultAsteriskServer;
import org.asteriskjava.live.ManagerCommunicationException;
import org.asteriskjava.live.MeetMeUser;
public class HelloLiveEvents implements AsteriskServerListener
{
private AsteriskServer asteriskServer;
public HelloLiveEvents()
{
asteriskServer = new DefaultAsteriskServer("localhost", "manager", "pa55w0rd");
}
public void run() throws ManagerCommunicationException
{
asteriskServer.addAsteriskServerListener(this);
}
public void onNewAsteriskChannel(AsteriskChannel channel)
{
System.out.println(channel);
}
public void onNewMeetMeUser(MeetMeUser user)
{
System.out.println(user);
}
public static void main(String[] args) throws Exception
{
HelloLiveEvents helloLiveEvents = new HelloLiveEvents();
helloLiveEvents.run();
}
}
### HelloLiveEverything
Finally, for every AsteriskChannel or MeetMeUser you can get examine
through the live API, you can also add a listener for properties that
change on that object.
The following code snippet shows a longer example that adds event
listeners for new channels or meet me users, and property change
listeners to new and old channels and users:
import org.asteriskjava.live.AsteriskChannel;
import org.asteriskjava.live.AsteriskQueue;
import org.asteriskjava.live.AsteriskServer;
import org.asteriskjava.live.AsteriskServerListener;
import org.asteriskjava.live.DefaultAsteriskServer;
import org.asteriskjava.live.ManagerCommunicationException;
import org.asteriskjava.live.MeetMeRoom;
import org.asteriskjava.live.MeetMeUser;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeEvent;
public class HelloLiveEverything implements AsteriskServerListener, PropertyChangeListener
{
private AsteriskServer asteriskServer;
public HelloLiveEverything()
{
asteriskServer = new DefaultAsteriskServer("localhost", "manager", "pa55w0rd");
}
public void run() throws ManagerCommunicationException
{
// listen for new events
asteriskServer.addAsteriskServerListener(this);
// add property change listeners to existing objects
for (AsteriskChannel asteriskChannel : asteriskServer.getChannels())
{
System.out.println(asteriskChannel);
asteriskChannel.addPropertyChangeListener(this);
}
for (AsteriskQueue asteriskQueue : asteriskServer.getQueues())
{
System.out.println(asteriskQueue);
for (AsteriskChannel asteriskChannel : asteriskQueue.getEntries())
{
asteriskChannel.addPropertyChangeListener(this);
}
}
for (MeetMeRoom meetMeRoom : asteriskServer.getMeetMeRooms())
{
System.out.println(meetMeRoom);
for (MeetMeUser user : meetMeRoom.getUsers())
{
user.addPropertyChangeListener(this);
}
}
}
public void onNewAsteriskChannel(AsteriskChannel channel)
{
System.out.println(channel);
channel.addPropertyChangeListener(this);
}
public void onNewMeetMeUser(MeetMeUser user)
{
System.out.println(user);
user.addPropertyChangeListener(this);
}
public void propertyChange(PropertyChangeEvent propertyChangeEvent)
{
System.out.println(propertyChangeEvent);
}
public static void main(String[] args) throws Exception
{
HelloLiveEverything helloLiveEverything = new HelloLiveEverything();
helloLiveEverything.run();
}
}