Is it advantageous to create a Spring bean when I can access the only static method directly with class name

Question

I think my understanding of spring beans is a bit off.

I was working on my project and I was thinking about this situation.

Say I have class Foo

class Foo(){   
   public void doSomething(Object a , Object b){ // input parameters does not matter actually.
      //do something
   }
}

If I am using this class in another class like :

class Scheduler{
  ....
 @Autowired
 private Foo foo;

 someMethod(){
    foo.doSomeThind(a,b);
 }
  ....
}

In the above case Instead of Autowiring the Foo, I can make doSomeThing static and directly use Foo.doSomeThing(a,b)

I was just wondering if there any advantage of creating a bean or if there any disadvantage of using static methods like this?

If they are same, When should I go for spring bean and when should do I simply use a static method?

Answer 1

Static methods are ok for small utility functions. The limitation of static code is that you can't change it's behavior without changing code itself.

Spring, on the other hand, gives you flexibility.

1. IoC. Your classes don't know about the exact implementation of their dependencies, they just rely on the API defined by interface. All connections are specified in configuration, that can be different for production/test/other.

2. Power of metaprogramming. You can change the behavior of your methods by merely marking them (via annotations of in xml). Thus, you can wrap method in transactions, make it asynchronous or scheduled, add custom AOP interceptors, etc.

3. Spring can instrument your POJO method to make it an endpoint to remote web service/RPC.

http://docs.spring.io/spring-framework/docs/current/spring-framework-reference/html/

Answer 2

Methods in Spring beans can benefit from dependency injection whereas static methods cannot. So, an ideal candidate for static method is the one that does things more or less independently and is not envisioned to ever need any other dependency (say a DAO or Service)