What Is Spring Autowiring Example?

What is spring Autowiring?

Autowiring feature of spring framework enables you to inject the object dependency implicitly.

It internally uses setter or constructor injection.

Autowiring can’t be used to inject primitive and string values..

What is use of @autowired in spring?

The @Autowired annotation can be used to autowire bean on the setter method just like @Required annotation, constructor, a property or methods with arbitrary names and/or multiple arguments. …

What are different types of Autowiring in spring?

This means that it is possible to automatically let Spring resolve collaborators (other beans) for your beans by inspecting the contents of the BeanFactory. This is called spring bean autowiring. The autowiring functionality has four modes. These are ‘ no ‘, ‘ byName ‘, ‘ byType ‘ and ‘ constructor ‘.

The reasons why field injection is frowned upon are as follows: You cannot create immutable objects, as you can with constructor injection. Your classes have tight coupling with your DI container and cannot be used outside of it. Your classes cannot be instantiated (for example in unit tests) without reflection.

What is @qualifier in spring?

Advertisements. There may be a situation when you create more than one bean of the same type and want to wire only one of them with a property. In such cases, you can use the @Qualifier annotation along with @Autowired to remove the confusion by specifying which exact bean will be wired.

What is spring bean life cycle?

A “Spring bean” is just a Spring managed instantiation of a Java class. The Spring IoC container is responsible for instantiating, initializing, and wiring beans. The container also manages the life cycle of beans. Spring provides several ways through which you can tap into the bean lifecycle.