Listeners

Listeners are unique to JIRA, and a very powerful way to extend it.

JIRA has a complete event subsystem which fires events whenever anything happens inside the application. For example an ISSUE_CREATED event is fired whenever an issue is created.

A Listener is a class that implements one of the Listener interfaces. It is then called whenever events occur in JIRA. Using those events, you can then perform any action you want. For example the email sent by JIRA is driven by the MailListener.

Listeners are most useful when you want to drive or affect external systems from events which occur within JIRA.

On this page:

Listener Interfaces

There are currently two different concrete Listeners within JIRA (both of which extend the base JiraListener interface).

Example Listeners

The examples provided may be freely used and modified for use in your own environment. The source of all examples is available and should give you good overview of how simple it is to write your own listeners. Both example listeners are included with JIRA 2.1, and both implement UserEventListener and IssueEventListener.

• DebugListener (source) — This is a very simple listener that prints events and their content to System.out whenever they are received. To test this listener, add a listener with the class com.atlassian.jira.event.listeners.DebugListener .
• MailListener (source) — This listener is how mail notifications are currently sent from within JIRA, and a good example of a more complex listener. It basically listens for events, and turns them into email notifications using Velocity templates to generate the mail bodies.
  This listener is usually always turned on in JIRA — see Email Notifications for more details. If you want to write more complex or more specific notifications, you can disable the internal MailListener and add your own.

Other examples of useful tasks that can be accomplished with listeners are:

• Send SMS or IM notifications — A listener could easily send notifications for various events via SMS or instant messenger (e.g. ICQ or AIM) - or anywhere that you have a Java library to send messages.
• Group notifications — A listener could notify certain groups of issue changes, depending on the content of the issue. For example any issue containing "windows" in the environment could notify your "windows-developers" group.

Registering a Listener

To register a listener:

1. Make sure your listener class is in the classpath where JIRA can see it - the best locations are usually the WEB-INF/classes or WEB-INF/lib (as a JAR) directories within the JIRA web application.
2. Log in as a user with the 'JIRA System Administrators' global permission.
3. Bring up the administration page by clicking either the 'Administration' link on the top bar or the title of the Administration box on the dashboard.
4. Click the 'Listeners' link in the 'System' section of the left-hand navigation column.
5. Enter a 'Name' (an appropriate name for this listener) and 'Class' (the fully qualified class of your listener) for your listener and click 'Add'.
6. The listener will now be added. Click 'Edit' for your listener to edit its properties.

Editing Listener Properties

You can edit a listeners properties by clicking 'Edit' for that listener in the 'Listeners' section of the 'Administration' tab.

When defining your own Listener, there is a method getAcceptedParams to overload for defining the parameter names, pass as an array of String objects. The DebugParamListener class is an example of doing this.

Removing a Listener

To remove a listener, click 'Del' for that listener in the 'Listeners' section of the 'Administration' tab.

Custom Events

With the ability to add custom events to JIRA, the Listener must be updated to deal with the event as appropriate. This is possible by providing an implementation for the method customEvent(IssueEvent event) in the Listener. For example, the MailListener implementation passes the custom event on for notification processing. The DebugListener logs that the custom event has been fired.