How to invoke a webhook when a JIRA event is fired?

Question

I am new to Atlassian programming and I want to invoke an external application via REST when an event is fired in JIRA, for instance when the priority of an issue is changed. (An event is fired when I change the priority in a JIRA issue, isn't it?)
I have registered the URL of a SpringBoot application as a webhook in JIRA so that this springBoot app shall be informed via a REST call that something happened in a JIRA project.

Did I understand webhooks correctly that I can use them this way?

How can I achieve that the event gets to the SpringBoot app/webhook?

Is there a way to test that an event is really fired from wihtin JIRA? How can I test this?

D. U. · Answer

I tried this in the meantime because I didn't had any else idea. ;-)
The checkboxes weren't activated because I thought that when "All events" is used I don't have to check the checkboxes.

However, Josh, you were right! I didn't checked them...and that was the problem.

Thank you, Josh! :-))

Josh Steckler · Answer

In your Webhook configuration, you have issue-updated checked?

D. U. · Answer

Hi Josh.

Thank you for this hint. I set up a requestb.in and then I made a change to a JIRA issue. The callback defined in the webhook was reached with a filled request body (JSON) and these headers:

HEADERS

Total-Route-Time: 0

Connect-Time: 0

X-Request-Id: 4c4396cc-e69e-49d1-815c-47e6eac0dfa9

Via: 1.1 localhost (Apache-HttpClient/4.4.1 (cache)), 1.1 vegur

Host: requestb.in

Connection: close

Content-Type: application/json; charset=UTF-8

User-Agent: Atlassian HttpClient 0.23.3 / JIRA-7.6.1 (76002) / Default

Cf-Visitor: {"scheme":"https"}

Accept: */*

Accept-Encoding: gzip

Cf-Connecting-Ip: 84.175.85.213

Cf-Ray: 3cd11a95cb812702-FRA

Content-Length: 1369

Cf-Ipcountry: DE

My SpringBoot app's method defined in the webhook now is called...but unfortunately only when I edit a comment. Not, when creating a new issue or reassigning the issue to another person, .. What do I have to do here?