SecurityUtils.getSubject().getSession(true).getAttribute()

This code retrieves an attribute from the user's session in Apache Shiro.

Explanation:

- `SecurityUtils.getSubject()` returns the currently authenticated subject (i.e., user) in the application.
- `.getSession(true)` retrieves the user's session (or creates a new one if it doesn't exist yet) and returns a `Session` object.
- `.getAttribute()` is a method of the `Session` object that retrieves an attribute stored in the session. It takes a single parameter, which is the name of the attribute to retrieve.

Therefore, the full expression `SecurityUtils.getSubject().getSession(true).getAttribute()` retrieves an attribute from the user's session. The actual name of the attribute being retrieved is not specified in this code and would need to be provided as an argument to the `getAttribute()` method.