See the comments below Find or insert based on unique key with Hibernate on Stack Overflow. I tried the solution proposed by Vlad Mihalcea, but I think the "find part" is not really working this way, at least if MySQL 5.5.x is used.
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create a database 'demo' with user 'demo' and password 'demo', see
src/test/resources/application.properties -
run all the tests (there is only one ;-)) with:
mvn clean test -
the test should fail with some output similar to the following:
Thread 2: no bean found by findByName("dummy")
Thread 1: no bean found by findByName("dummy")
Thread 2: numChanged: 1
Thread 2: bean was created with id: 15
Thread 2: found bean by findOne(15)
Thread 1: numChanged: 1
Thread 1: bean was created with id: 15
Thread 1: no bean found by findOne(15)
Thread 1: no bean found by findByName("dummy")
Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 3.794 sec
<<< FAILURE! - in com.example.demo.OnDuplicateKeyUpdateTests
testConcurrentFindOrCreate(com.example.demo.OnDuplicateKeyUpdateTests)
Time elapsed: 0.42 sec <<< FAILURE!
java.lang.AssertionError:
Expected size:<2> but was:<1> in: [...]