03_Autowired.md

@Autowired

What is Autowired?

• An annotation used in the Spring Framework for automatic injection
• Spring configures relationships between objects through DI (Dependency Injection), maintaining the application's loose coupling
  • By using the @Autowired annotation, you can specify that the Spring Container automatically injects the Bean object corresponding to the field, constructor, or method parameter
• Using the @Autowired annotation reduces code complexity and makes maintenance easier, since the Spring Framework automatically injects dependencies without the need to directly create or inject dependent objects

Order of Finding Dependent Objects When @Autowired is Applied

1. Search for a bean object with the same type

   • If there is 1, use that bean object
   • If @Qualifier is specified, the bean object must have the same value

2. If there are two or more bean objects with the same type and @Qualifier is not present, find a bean object with the same name

   → If found, use that object

3. If there are two or more bean objects with the same type, find the bean object specified by @Qualifier

   → If found, use that object

4. If none of the above cases apply, the container throws an Exception