Examples

Here we provide some examples of UML sequence diagrams:

Online bookshop UML sequence diagram
Purpose: An example of high level UML sequence diagram for Online Bookshop.
Summary: Online customer can search book catalog, view description of a selected book, add book to shopping cart, do checkout.

Submit comments to Pluck using DWR, AJAX, JSON
Purpose: An example of UML sequence diagram which shows how user comments on some article are submitted to Pluck using various AJAX technologies.
Summary: Comments submitted by a web user are first validated by the web site which is hosting commented article. DWR technology (AJAX for Java) is used to convert user comments HTML form data into Java object and possible validation errors - back into JavaScript callbacks for errors. Comments that look Ok are submitted to Pluck server hosting all comments to all articles.

Facebook user authentication in a web application
Purpose: An example of sequence diagram which shows how Facebook user could be authenticated in a web application to allow access to his/her Facebook resources.
Summary: Facebook uses OAuth 2.0 protocol framework which enables web application (called “client”), which is usually not the Facebook resource owner but is acting on the Facebook user’s behalf, to request access to resources controlled by the FB user and hosted by the Facebook server. Instead of using the Facebook user credentials to access protected resources, the web application obtains an access token.

Spring and Hibernate transaction management
Purpose: An example of UML sequence diagram which illustrates transaction management combined with exception handling using Spring framework for enterprise Java™ and Hibernate.
Summary: Spring application development framework for enterprise Java™ integrates Hibernate transaction management. Business method execution could complete (successfully or not) without throwing any exception, or by throwing some Java runtime (unchecked) exception or some business (checked) exception. Transaction interceptor will will decide to try to commit transaction or to roll it back.

https://www.uml-diagrams.org/sequence-diagrams-examples.html