[JAVA] ProxyFactory is convenient when you want to test AOP in Spring!

Overview

--I want to test if the AOP settings are working ――However, it is difficult to test if you are performing processing that causes side effects to the outside (eg transaction, log output ... etc). --Proxy Factory is convenient in such a case

First, write a normal test code

Prepare the following Service class and MethodInterceptor as a prerequisite.

AOP target Service

@Service
class SampleService {
    fun execute() {
        println("SampleService#execute")
    }
}

Interceptor

class SampleInterceptor(
        private val name: String
) : MethodInterceptor {
    override fun invoke(invocation: MethodInvocation?): Any? {
        println("intercept by $name")
        return invocation?.proceed()
    }
}

class SampleServicePointCut : StaticMethodMatcherPointcut() {
    override fun matches(method: Method, @Nullable targetClass: Class<*>?): Boolean {
        return targetClass?.let { SampleService::class.java.isAssignableFrom(it) } ?: false
    }
}

config

@Configuration
@EnableAspectJAutoProxy(proxyTargetClass = true)
class AopConfig {

    @Bean
    fun interceptorA(): Advisor {
        return DefaultPointcutAdvisor(SampleServicePointCut(), SampleInterceptor("configured interceptor"))
    }
}

Test code

@SpringBootApplication
class SpringTestApplication

@RunWith(SpringRunner::class)
@SpringBootTest(classes = [SpringTestApplication::class])
internal class SampleServiceTest {
    @Autowired
    private lateinit var service: SampleService

    @Test
    fun test() {
        service.execute()
    }
}

Execution result

intercept by configured interceptor
SampleService#execute

Let's write the test code as follows using ProxyFactory

Test code using ProxyFactory

@Test
fun testByProxy() {
    val factory = ProxyFactory(SampleService())
    factory.addAdvisor(DefaultPointcutAdvisor(SampleServicePointCut(), SampleInterceptor("Proxy")))
    val proxy = factory.proxy as SampleService
    proxy.execute()
}

Execution result

intercept by Proxy
SampleService#execute

Kotlin may create a Util function

It is also good to create a util function using Extension.

Example using kotlin extension Test code using ProxyFactory

@Test
fun testByProxy() {
    val proxy = SampleService().proxy {
        addAdvisor(DefaultPointcutAdvisor(SampleServicePointCut(), SampleInterceptor("Proxy")))
    }
    proxy.execute()
}

@Suppress("UNCHECKED_CAST")
fun <T : Any> T.proxy(settings: ProxyFactory.() -> Unit): T {
    return ProxyFactory(this).also { settings(it) }.proxy as T
}

AspectJProxyFactory if using @Aspect

Service and Config

@Aspect
@Component
class SampleAspect(
        private val name: String = ""
) {
    @Before("execution(* SampleAspectService.*(..))")
    fun advice() {
        println("advice by $name")
    }
}

@Service
class SampleAspectService {
    fun execute() {
        println("SampleAspectService#execute")
    }
}

Test code

@Test
fun testAspectProxy() {
    val factory = AspectJProxyFactory(SampleAspectService())
    factory.addAspect(SampleAspect("proxy"))
    val proxy = factory.getProxy() as SampleAspectService
    proxy.execute()
}

Execution result

advice by proxy
SampleAspectService#execute