🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.
▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube
▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube
1. Introduction
In the Spring framework, @Autowired and @Resource are annotations used for dependency injection, which is a way to achieve Inversion of Control (IoC) by allowing the Spring container to inject dependencies into components. @Autowired is Spring's own annotation, while @Resource is specified by the JSR-250 Java standard.
2. Key Points
1. @Autowired is part of the Spring framework and injects dependencies by type.
2. @Resource is a standard annotation intended for dependency injection by name.
3. @Autowired has support for additional features such as the @Qualifier annotation for further disambiguation.
4. @Resource can be used outside of the Spring context, as it's not Spring-specific.
3. Differences
| @Autowired | @Resource |
|---|---|
| Spring-specific annotation. | JSR-250 Java standard annotation. |
| Performs dependency injection by type. | Performs dependency injection by name (and optionally by type). |
| Can be used with @Qualifier to further specify the bean to inject. | Has a name attribute to indicate the specific bean to inject. |
| Does not need to specify a bean name unless using @Qualifier. | You specify the bean name explicitly using the name attribute. |
4. Example
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import javax.annotation.Resource;
public class MyService {
// @Autowired injects by type
@Autowired
private MyDependency myDependency;
// @Autowired with @Qualifier injects a specific bean by name
@Autowired
@Qualifier("specificDependency")
private MyDependency anotherDependency;
// @Resource injects by name
@Resource(name="myResource")
private MyDependency resourceDependency;
}
public class MyDependency {
// Class content
}
Output:
// No output, since this is a demonstration of annotations usage.
Explanation:
1. @Autowired without @Qualifier injects the MyDependency bean based on its type.
2. @Autowired with @Qualifier("specificDependency") specifies exactly which bean should be injected when multiple beans of the same type exist.
3. @Resource(name="myResource") injects the MyDependency bean by its name.
5. When to use?
- Use @Autowired when you are working within the Spring ecosystem and want to inject dependencies by type and are okay with Spring handling the resolution.
- Use @Resource when you want to be more explicit about the bean name or when you are writing code that is possibly outside of the Spring framework.
My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:
Build REST APIs with Spring Boot 4, Spring Security 7, and JWT
![[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25](https://img-c.udemycdn.com/course/750x422/6852721_b512_2.jpg "[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25")
[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25
ChatGPT + Generative AI + Prompt Engineering for Beginners
Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)
Available in Udemy for Business
Building Real-Time REST APIs with Spring Boot - Blog App
Available in Udemy for Business
Building Microservices with Spring Boot and Spring Cloud
Available in Udemy for Business
Java Full-Stack Developer Course with Spring Boot and React JS
Available in Udemy for Business
Build 5 Spring Boot Projects with Java: Line-by-Line Coding
Testing Spring Boot Application with JUnit and Mockito
Available in Udemy for Business
Spring Boot Thymeleaf Real-Time Web Application - Blog App
Available in Udemy for Business
Master Spring Data JPA with Hibernate
Available in Udemy for Business
Spring Boot + Apache Kafka Course - The Practical Guide
Available in Udemy for Business
Comments
Post a Comment
Leave Comment