Spring autowired bean for @Aspect aspect is null

Question

I have the following spring configuration:

Answer 1

@Configurable(autowire = Autowire.BY_TYPE)

Add this annotation to your Aspectj class. Then it will be handled by Spring IOC.

Answer 2

For Spring Boot to use @Autowired with AspectJ I have found the following method. In configuration class add your aspect:

@Configuration
@ComponentScan("com.kirillch.eqrul")
public class AspectConfig {

    @Bean
    public EmailAspect theAspect() {
        EmailAspect aspect = Aspects.aspectOf(EmailAspect.class);
        return aspect;
    }

}

Then you can successfully autowire your services in your aspect class:

@Aspect
public class EmailAspect {

    @Autowired
    EmailService emailService;

Answer 3

I dont have 50 rep to comment on a question so here is another answer relating to @ Jitendra Vispute answer. The official Spring doc mentions:

You may register aspect classes as regular beans in your Spring XML configuration, or autodetect them through classpath scanning - just like any other Spring-managed bean. However, note that the @Aspect annotation is not sufficient for autodetection in the classpath: For that purpose, you need to add a separate @Component annotation (or alternatively a custom stereotype annotation that qualifies, as per the rules of Spring’s component scanner).Source: Spring '4.1.7.Release' documentation.

This would mean that adding a @Component annotation and adding the @ComponentScan on your Configuration would make @Jitendra Vispute's example work. For the spring boot aop sample it worked, though I did not mess around with context refreshing.Spring boot aop sample:

Application:

package sample.aop;
@SpringBootApplication
public class SampleAopApplication implements CommandLineRunner {
    // Simple example shows how an application can spy on itself with AOP
    @Autowired
    private HelloWorldService helloWorldService;
    @Override
    public void run(String... args) {
        System.out.println(this.helloWorldService.getHelloMessage());
    }
    public static void main(String[] args) throws Exception {
        SpringApplication.run(SampleAopApplication.class, args);
    }
}

The application should also run as plain Spring Framework application with the following annotations instead of @SpringBootApplication:

• @Configuration
• @EnableAspectJAutoProxy
• @ComponentScan

and an AnnotationConfigApplicationContext instead of SpringApplication.

Service:

package sample.aop.service;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component
public class HelloWorldService {
    @Value("${name:World}")
    private String name;
    public String getHelloMessage() {
        return "Hello " + this.name;
    }
}

Monitor Aspect:

package sample.aop.monitor;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class ServiceMonitor {
    @AfterReturning("execution(* sample..*Service.*(..))")
    public void logServiceAccess(JoinPoint joinPoint) {
        System.out.println("Completed: " + joinPoint);
    }
}