How does autowiring work in Spring?

Question

I\'m a little confused as to how the inversion of control (IoC) works in Spring.

Say I have a service class called UserServic

Answer 1

@Autowired is an annotation introduced in Spring 2.5, and it's used only for injection.

For example:

class A {

    private int id;

    // With setter and getter method
}

class B {

    private String name;

    @Autowired // Here we are injecting instance of Class A into class B so that you can use 'a' for accessing A's instance variables and methods.
    A a;

    // With setter and getter method

    public void showDetail() {
        System.out.println("Value of id form A class" + a.getId(););
    }
}