Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:
Once the early-adopter seats are all used, the price will go up and stay at $33/year.
Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.
Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.
To learn more about Java features on Azure Container Apps, visit the documentation page.
You can also ask questions and leave feedback on the Azure Container Apps GitHub page.
Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.
Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.
To learn more about Java features on Azure Container Apps, you can get started over on the documentation page.
And, you can also ask questions and leave feedback on the Azure Container Apps GitHub page.
Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.
Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.
With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.
Try a 14-Day Free Trial of Orkes Conductor today.
Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.
Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.
With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.
Try a 14-Day Free Trial of Orkes Conductor today.
Mocking is an essential part of unit testing, and the Mockito library makes it easy to write clean and intuitive unit tests for your Java code.
Get started with mocking and improve your application tests using our Mockito guide:
Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.
Get started with understanding multi-threaded applications with our Java Concurrency guide:
Spring 5 added support for reactive programming with the Spring WebFlux module, which has been improved upon ever since. Get started with the Reactor project basics and reactive programming in Spring Boot:
Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.
But these can also be overused and fall into some common pitfalls.
To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:
Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:
Yes, Spring Security can be complex, from the more advanced functionality within the Core to the deep OAuth support in the framework.
I built the security material as two full courses - Core and OAuth, to get practical with these more complex scenarios. We explore when and how to use each feature and code through it on the backing project.
You can explore the course here:
All Access is finally out, with all of my Spring courses. Learn JUnit is out as well, and Learn Maven is coming fast. And, of course, quite a bit more affordable. Finally.
>> GET THE COURSE
Spring Data JPA is a great way to handle the complexity of JPA with the powerful simplicity of Spring Boot.
Get started with Spring Data JPA through the guided reference course:
End-to-end testing is a very useful method to make sure that your application works as intended. This highlights issues in the overall functionality of the software, that the unit and integration test stages may miss.
Playwright is an easy-to-use, but powerful tool that automates end-to-end testing, and supports all modern browsers and platforms.
When coupled with LambdaTest (an AI-powered cloud-based test execution platform) it can be further scaled to run the Playwright scripts in parallel across 3000+ browser and device combinations:
Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:
Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:
1. Overview
Bean is a key concept of the Spring Framework. So understanding this notion is crucial to get the hang of the framework and use it in an effective way.
Unfortunately, there aren’t clear answers to the simple question of what a Spring bean really is. Some explanations go to such a low level that the big picture is missed, whereas others are too vague.
This tutorial will try to shed light on the topic, starting with a description in the official documentation.
Further reading:
Why Choose Spring as Your Java Framework?
A quick and practical overview of the main value proposition of Spring framework.
Understanding getBean() in Spring
Learn about the different variants of Spring's BeanFactory.getBean() method for retrieving a bean instance from the Spring container
2. Bean Definition
Here’s a definition of beans in the Spring Framework documentation:
In Spring, the objects that form the backbone of your application and that are managed by the Spring IoC container are called beans. A bean is an object that is instantiated, assembled, and otherwise managed by a Spring IoC container.
This definition is concise and gets to the point but fails to elaborate on an important element: the Spring IoC container. Let’s take a closer look to see what it is and the benefits it brings in.
3. Inversion of Control
Simply put, Inversion of Control (IoC) is a process in which an object defines its dependencies without creating them. This object delegates the job of constructing such dependencies to an IoC container.
Let’s start with the declaration of a couple of domain classes before diving into IoC.
3.1. Domain Classes
Assume we have a class declaration:
public class Company {
private Address address;
public Company(Address address) {
this.address = address;
}
// getter, setter and other properties
}This class needs a collaborator of type Address:
public class Address {
private String street;
private int number;
public Address(String street, int number) {
this.street = street;
this.number = number;
}
// getters and setters
}3.2. Traditional Approach
Normally, we create objects with their classes’ constructors:
Address address = new Address("High Street", 1000);
Company company = new Company(address);There’s nothing wrong with this approach, but wouldn’t it be nice to manage the dependencies in a better way?
Imagine an application with dozens or even hundreds of classes. Sometimes we want to share a single instance of a class across the whole application, other times we need a separate object for each use case, and so on.
Managing such a number of objects is nothing short of a nightmare. This is where inversion of control comes to the rescue.
Instead of constructing dependencies by itself, an object can retrieve its dependencies from an IoC container. All we need to do is to provide the container with appropriate configuration metadata.
3.3. Bean Configuration
First off, let’s decorate the Company class with the @Component annotation:
@Component
public class Company {
// this body is the same as before
}Here’s a configuration class supplying bean metadata to an IoC container:
@Configuration
@ComponentScan(basePackageClasses = Company.class)
public class Config {
@Bean
public Address getAddress() {
return new Address("High Street", 1000);
}
}The configuration class produces a bean of type Address. It also carries the @ComponentScan annotation, which instructs the container to look for beans in the package containing the Company class.
When a Spring IoC container constructs objects of those types, all the objects are called Spring beans, as they are managed by the IoC container.
3.4. IoC in Action
Since we defined beans in a configuration class, we’ll need an instance of the AnnotationConfigApplicationContext class to build up a container:
ApplicationContext context = new AnnotationConfigApplicationContext(Config.class);A quick test verifies the existence and the property values of our beans:
Company company = context.getBean("company", Company.class);
assertEquals("High Street", company.getAddress().getStreet());
assertEquals(1000, company.getAddress().getNumber());The result proves that the IoC container has created and initialized beans correctly.
4. Conclusion
This article gave a brief description of Spring beans and their relationship with an IoC container.
The code backing this article is available on GitHub. Once you're logged in as a Baeldung Pro Member, start learning and coding on the project.
