How to use Autowired annotations

Question

I have a doubt to use autowire annotation in different scenarios...

public Class A {
  @Autowired
  public B b;

  public void print() {
    System.out.println("the value is " + b.getValue());
  }

}

Example 2:

public Class A {
  public B b;

  @Autowired
  Public A(B b){}

  public void print() {
    System.out.println("the value is " + b.getValue());
  }
}

Answer 1

The first method to autowire objects is called field-injection and the second one is called constructor-injection . There are many posts on SO about these two topics! Eg What exactly is Field Injection and how to avoid it? This should answer all of your questions.