When using Dependency Injection (DI) in Java, one common feature that can be used with DI frameworks is the ability to define the scope of the objects being managed by the container. One of these scopes is the “prototype” scope.

What is Prototype Scope?

The prototype scope is one of the common object scopes used in DI frameworks. In this scope, a new instance of an object is created every time it is requested from the DI container. This means that each time the object is injected or retrieved, a new instance will be created and returned.

Why Use Prototype Scope?

Prototype scope is useful in scenarios where you want a new instance of an object every time it is requested. Some scenarios where prototype scope may be used include:

• Objects with state that needs to be reset or initialized each time it is used.
• Thread safety requirements where each thread should have its own instance of an object.
• Objects with expensive resource acquisition that need to be released and created again to avoid resource leaks.

Example:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

@Configuration
public class AppConfig {

    @Bean
    @Scope("prototype")
    public MyPrototypeBean myPrototypeBean() {
        return new MyPrototypeBean();
    }
}

In the example above, we are using the Spring Framework for Dependency Injection. The @Scope("prototype") annotation is used to declare the scope of the myPrototypeBean bean as prototype. This means that every time this bean is injected or retrieved, a new instance of MyPrototypeBean is created and returned.

Conclusion

Prototype scope in Dependency Injection allows us to create new instances of objects every time they are requested. This can be useful in various scenarios where a fresh instance is required for each usage. By understanding and utilizing the prototype scope, we can effectively manage object creation and resource utilization in Java applications.

#Java #DependencyInjection #PrototypeScope