40.2 Testing Spring applications
One of the major advantages of dependency injection is that it should make your code easier to unit test. You can simply instantiate objects using the new
operator without even involving Spring. You can also use mock objects instead of real dependencies.
Often you need to move beyond ‘unit testing’ and start ‘integration testing’ (with a Spring ApplicationContext
actually involved in the process). It’s useful to be able to perform integration testing without requiring deployment of your application or needing to connect to other infrastructure.
The Spring Framework includes a dedicated test module for just such integration testing. You can declare a dependency directly to org.springframework:spring-test
or use the spring-boot-starter-test
‘Starter’ to pull it in transitively.
If you have not used the spring-test
module before you should start by reading the relevant section of the Spring Framework reference documentation.