Can we use @component annotation in interface?
Some times interfaces are annotated with @Component annotation. Then my obvious reasoning was that classes that implement such interface will be treated as components as well.
Are Abstract classes better than interface?
The short answer: An abstract class allows you to create functionality that subclasses can implement or override. An interface only allows you to define functionality, not implement it. And whereas a class can extend only one abstract class, it can take advantage of multiple interfaces.
Can we use @autowired in abstract class?
We can’t use @Autowired on a constructor of an abstract class. Spring doesn’t evaluate the @Autowired annotation on a constructor of an abstract class. The subclass should provide the necessary arguments to the super constructor.
What is the purpose of @component annotation?
@Component is an annotation that allows Spring to automatically detect our custom beans. In other words, without having to write any explicit code, Spring will: Scan our application for classes annotated with @Component. Instantiate them and inject any specified dependencies into them.
What is diff between abstract class and interface?
Abstract class can inherit another class using extends keyword and implement an interface. Interface can inherit only an inteface. Abstract class can be inherited using extends keyword. Interface can only be implemented using implements keyword.
What is the similarities difference between an abstract class and interface?
Both Interfaces and Abstract Classes can have methods and variables, but neither of them can be instantiated. All the variables declared within the interface are final. However, the variables declared in Abstract Classes can be non-final and can be modified by the user-defined classes.
Can I use @component instead of @service?
If your component is a generic component, not really living at the service layer, or is accessible but could hold state, then use @Component . If your component is a specific service, living at the service layer, or is accessible and does not inherently hold state, use @Service .
What happens if we use @component instead of service?
We can use @Component across the application to mark the beans as Spring’s managed components. Spring will only pick up and register beans with @Component, and doesn’t look for @Service and @Repository in general. @Service and @Repository are special cases of @Component.
Can we inject in abstract class?
Second, setter injection is possible in an abstract class, but it’s risky if we don’t use the final keyword for the setter method. The application may not be stable if a subclass overrides the setter method.
Can I use @component instead of controller?
There is no difference between @Component , @Service , @Controller , @Repository . @Component is the Generic annotation to represent the component of our MVC.
Can we use @component instead of service?
Can we use @component instead of controller?