在更新以测试Spring事务管理时如何模拟异常？

Question

I have under the same spring managed transaction an array of updates as below:

someRepositoryA.updateEntityA(...)
someRepositoryB.updateEntityB(...)
someRepositoryC.updateEntityC(...)

How can I simulate that someRepositoryB.updateEntityB(...) throws an Exception ? That will allow me to see that the changes made by A were revoked. Since I will test the transaction I cannot mock the repository, but I will use some in-memory database.

Answer 1

I wouldn't simulate an exception, I'd make something genuinely go wrong.

You're using an in-memory database so you have control of your test data. Also it's a better test (less chance of bad assumptions invalidating your results) if you're recreating a real problem instead of faking out something.

The easiest way to test your transaction would be to have the test create a B with data chosen so that the update will cause a referential integrity constraint to be violated (Do you have any not-null constraints? Otherwise you can introduce an invalid primary key value, by re-using an existing value). The RI violation will cause an exception to get thrown.