JUnit Assert.assertSame
This test, on its own, is not enough. Additionally, the test is called testUpdated, but it does not actually test that the value is updated.

What it does is:


find an object based on a key value
it modifies some non-key content
it 'persists' the changes
it finds an object for the same key as before
it tests that the object it found the second time is the identical object to the first.


At no point in this process have you actually tested that the values you think you changed on the object, actually did change.

Additionally, you never tested whether those changes were persisted to the database/store.

What I would expect a test like this to do, is to:


get the object using the key
make the changes
assert that the values have changed to the new values.
persist the changes
assert that a persist happened (some timestamp in the database maybe)?
use an independent mechanism to check that the values in the database match the values in the object (a different database connection, a different DAO instance, something).
ensure that finding the same key value finds the same instance as before.


That is a lot of things to change, which means the test, on it's own, is not enough, and should be included with a bunch of other tests, each one testing different parts of the process.