Spring AOP - Setting Advice on a POJO getter - advice is not called - spring

Question

I'm pretty new to Spring and I'd like to use Spring AOP to be able to fire an advice when a POJO getter is being called.
I created a simple POJO:
package com.atlas.datastore.datadomain;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.stereotype.Component;
#Component
public class Person
{
private String name;
public String getName() {
System.out.println(name);
return name;
}
public void setName(String name) {
this.name = name;
}
}
And I created an Aspect for the name getter:
package com.atlas.datastore.aspects;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;
#Component
#Aspect
public class personAspect {
#Pointcut("execution(* com.atlas.datastore.datadomain.Person.getName())")
private void getName() {}
#Before("getName()")
public void doBeforeTask(){
System.out.println("My name is: " );
}
}
I created a controller (spring boot simple application) to use the getter:
package com.example.Controller;
import com.atlas.datastore.datadomain.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
#RestController
#RequestMapping("/person")
public class PersonController {
#Autowired
private Person person;
#RequestMapping(value = "/{personId}", method = RequestMethod.GET)
#ResponseBody()
public Person personAction(#PathVariable String personId) {
person.setName("John");
person.getName();
return person;
}
}
When I run the application everything works fine and I can see that the advice is being fired.
The problem I have is that I do not want to auto-wire the Person object. When I create a Person with a default constructor (using new keyword), I see that the advice is not being fired:
package com.example.Controller;
import com.atlas.datastore.datadomain.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
#RestController
#RequestMapping("/person")
public class PersonController {
#RequestMapping(value = "/{personId}", method = RequestMethod.GET)
#ResponseBody()
public Person personAction(#PathVariable String personId) {
Person person = new Person();
person.setName("John");
person.getName();
return person;
}
}
In my configuration I am using the following annotation:
#EnableAspectJAutoProxy(proxyTargetClass = true)
I can see the following output in the log:
18:12:40.152 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Creating shared instance of singleton bean 'person'
18:12:40.152 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Creating instance of bean 'person'
18:12:40.152 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Eagerly caching bean 'person' to allow for resolving potential circular references
18:12:40.153 [main] DEBUG o.s.a.a.a.AnnotationAwareAspectJAutoProxyCreator - Creating implicit proxy for bean 'person' with 0 common interceptors and 2 specific interceptors
18:12:40.153 [main] DEBUG o.s.aop.framework.CglibAopProxy - Creating CGLIB proxy: target source is SingletonTargetSource for target object [com.atlas.datastore.datadomain.Person#7de4a01f]
18:12:40.154 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Finished creating instance of bean 'person'
I'd appreciate your help

Answer 1

Using the new operator to directly create an instance like Person person = new Person() bypasses the Spring and so Spring doesn't get a chance to inject the dependencies in this object or proxy this object.
To make Spring inject the dependencies or proxy for above scenarios where new operator is used, we need to Annotate the Person object as #Configurable, configure AnnotationBeanConfigurerAspect, use Spring LoadTimeWeaving and run the application with -javaagent .....
You can find sample usage of this at https://dzone.com/articles/domain-object-dependency-injection-with-spring

Answer 2

Instead of adding the #Pointcut to a domain object:
com.atlas.datastore.datadomain.Person.getName()
consider creating a service instead which takes a Person object as a parameter. Add the #Pointcut to the service method.
Inject the service into your web controller, and then call the service passing the 'new' Person.