What’s purpose of AopTestUtils.getTargetObject()?

Take example of AopTestUtils.getTargetObject(myRepository) is a method provided by the Spring Framework’s testing utilities. It is used to extract the actual object instance that is being proxied by Spring AOP (Aspect-Oriented Programming) for the given bean.

In the context of the previous code snippet, we are using AopTestUtils.getTargetObject(myRepository) to obtain the actual MyEntityRepository instance being proxied by Spring AOP. This is necessary because we need to get access to the underlying EntityManager used by the repository, which is not exposed by the repository interface itself.

By obtaining the actual instance being proxied, we can access the EntityManager and transaction associated with it to perform the multi-threaded save test.

Here’s an example of how you can use AopTestUtils.getTargetObject(myRepository) to extract the actual instance being proxied:

MyEntityRepository repo = context.getBean(MyEntityRepository.class);
MyEntityRepository targetRepo = (MyEntityRepository) AopTestUtils.getTargetObject(repo);
EntityManager em = targetRepo.getEntityManager();
// use the EntityManager to perform operations on the database
Note that AopTestUtils.getTargetObject() works by recursively unwrapping any nested proxies that might be present until it reaches the target object. In some cases, you may need to call it multiple times to extract the actual object instance.

More: here’s some additional information about AopTestUtils.getTargetObject():


The main purpose of AopTestUtils.getTargetObject() is to allow you to access the target object being proxied by Spring AOP in a testing context. This can be useful in cases where you need to access properties or methods that are not exposed by the proxy itself.


You can use AopTestUtils.getTargetObject() by passing in the proxied bean instance that you want to access. The method will then recursively unwrap any nested proxies until it reaches the actual target object.


In order to use AopTestUtils.getTargetObject(), your test class must be a Spring-managed bean (e.g., annotated with @SpringBootTest, @WebMvcTest, etc.), and the bean you want to access must be managed by the Spring container (e.g., it must be annotated with @Repository, @Service, etc.).


It’s important to note that AopTestUtils.getTargetObject() only works with Spring AOP proxies, and may not work with other types of proxies (e.g., JDK proxies, CGLIB proxies, etc.). Additionally, it only works with single-level proxies, so if you have multiple layers of proxies (e.g., a @Transactional proxy wrapping a @Cacheable proxy), you may need to call it multiple times to reach the actual target object.

Overall, AopTestUtils.getTargetObject() can be a useful tool in testing Spring applications, as it allows you to access the underlying objects being proxied by Spring AOP, which can be difficult to do otherwise.