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Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

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Once the early-adopter seats are all used, the price will go up and stay at $33/year.

Partner – Microsoft – NPI EA (cat = Baeldung)
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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.

Partner – Microsoft – NPI EA (cat= Spring Boot)
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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.

Partner – Orkes – NPI EA (cat=Spring)
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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.

Partner – Orkes – NPI EA (tag=Microservices)
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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.

eBook – Guide Spring Cloud – NPI EA (cat=Spring Cloud)
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eBook – Mockito – NPI EA (tag = Mockito)
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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:

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eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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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.

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eBook – Reactive – NPI EA (cat=Reactive)
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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:

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eBook – Java Streams – NPI EA (cat=Java Streams)
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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:

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eBook – Jackson – NPI EA (cat=Jackson)
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Do JSON right with Jackson

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eBook – HTTP Client – NPI EA (cat=Http Client-Side)
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Get the most out of the Apache HTTP Client

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eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

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Building a REST API with Spring?

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Course – LS – NPI EA (cat=Jackson)
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Get started with Spring and Spring Boot, through the Learn Spring course:

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Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:

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Course – LSS – NPI EA (cat=Spring Security)
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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:

>> Learn Spring Security

Course – All Access – NPI EA (cat= Spring)
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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.

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Course – LSD – NPI EA (tag=Spring Data JPA)
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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:

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Partner – LambdaTest – NPI EA (cat=Testing)
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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:

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Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
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Course – Spring Sale 2025 – NPI (cat=Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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1. Overview

In this tutorial, we’ll demonstrate how to use Swagger annotations to make our documentation more descriptive. First, we’ll learn how to add a description to different parts of the APIs, like methods, parameters, and error codes. Then we’ll see how to add request/response examples.

2. Project Setup

We’ll create a simple Products API that provides methods to create and get products.

To create a REST API from scratch, we can follow this tutorial from Spring Docs to create a RESTful web service using Spring Boot.

The next step will be to set up the dependencies and configurations for the project. We can follow the steps in this article for setting up Swagger 2 with a Spring REST API.

3. Creating the API

Let’s create our Products API and check the documentation generated.

3.1. Model

Let’s define our Product class:

public class Product implements Serializable {
    private long id;
    private String name;
    private String price;

    // constructor and getter/setters
}

3.2.  Controller

Let’s define the two API methods:

@RestController
@Tag(name = "Products API")
public class ProductController {

    @PostMapping("/products")
    public ResponseEntity<Void> createProduct(@RequestBody Product product) {
        //creation logic
        return new ResponseEntity<>(HttpStatus.CREATED);
    }

    @GetMapping("/products/{id}")
    public ResponseEntity<Product> getProduct(@PathVariable Long id) {
        //retrieval logic
        return ResponseEntity.ok(new Product(1, "Product 1", "$21.99"));
    }
}

When we run the project, the library will read all the exposed paths and create corresponding documentation.

Let’s view the documentation at the default URL http://localhost:8080/swagger-ui/index.html:

Swagger Documentation

We can further expand the controller methods to look at their respective documentation. Next, we’ll look at them in detail.

4. Making Our Documentation Descriptive

Now let’s make our documentation more descriptive by adding descriptions to different parts of the methods.

4.1. Add Description to Methods and Parameters

Let’s look at a few ways to make the methods descriptive. We’ll add descriptions to the methods, parameters, and response codes. Let’s start with the getProduct() method:

@Operation(summary = "Get a product by id", description = "Returns a product as per the id")
@ApiResponses(value = {
        @ApiResponse(responseCode = "200", description = "Successfully retrieved"), 
        @ApiResponse(responseCode = "404", description = "Not found - The product was not found")
    })
@GetMapping("/products/{id}")
public ResponseEntity<Product> getProduct(@PathVariable("id") @Parameter(name = "id", description = "Product id", example = "1") Long id) {
    //retrieval logic
    return ResponseEntity.ok(new Product(1, "Product 1", "$21.99"));
}

@Operation defines the properties of an API method. We added a name to the operation using the value property, and a description using the notes property.

@ApiResponses is used to override the default messages that accompany the response codes. For each response message we want to change, we need to add an @ApiResponse object.

For example, let’s say the product isn’t found, and our API returns an HTTP 404 status in this scenario. If we don’t add a custom message, the original message “Not found” can be hard to understand. The caller may interpret it as the URL is wrong. However, adding a description that “The product was not found” makes it clearer.

@Parameter defines the properties of method parameters. It can be used along with the path, query, header, and form parameters. We added a name, a value (description), and an example for the “id” parameter. If we don’t add the customization, the library will only pick up the name and type of the parameter, as we can see in the first image.

Let’s see how this changes the documentation:

Screenshot-2022-01-29-at-4.08.45-PM

Here we can see the name “Get a product id” alongside the API path /products/{id}. We can also see the description just below it.  Additionally, in the Parameters section, we have a description and an example for the field id. Finally, in the Responses section, we can see how the error descriptions for the 200 and 404 codes have changed.

4.2. Add Description and Examples to the Model

We can make similar improvements in our createProduct() method. Since the method accepts a Product object, it makes more sense to provide the description and examples in the Product class itself.

Let’s make some changes in the Product class to achieve this:

@Schema(name = "Product ID", example = "1", required = true)
private Long id;
@Schema(name = "Product name", example = "Product 1", required = false)
private String name;
@Schema(name = "Product price", example = "$100.00", required = true)
private String price;

The @Schema annotation defines the properties of the fields. We used this annotation on each field to set its name, example, and required properties.

Let’s restart the application and take a look at the documentation of our Product model again:

Screenshot-2022-01-29-at-4.07.33-PM

If we compare this to the original documentation image, we’ll find that the new image contains examples, descriptions, and red asterisks(*) to identify the required parameters.

By adding examples to models, we can automatically create example responses in every method which uses the model as an input or output. For example, from the image corresponding to the getProduct() method, we can see that the response contains an example containing the same values we provided in our model.

Adding examples to our documentation is important because it makes value formats even more precise. If our models contain fields like date, time, or price, an exact value format is necessary. Defining the format beforehand makes the development process more effective for both the API provider and the API clients.

5. Conclusion

In this article, we explored different ways to improve the readability of our API documentation. We learned how to document methods, parameters, error messages, and models using the annotations @Parameter, @Operation, @ApiResponses, @ApiResponse, and @Schema.

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.
Baeldung Pro – NPI EA (cat = Baeldung)
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Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

>> Explore a clean Baeldung

Once the early-adopter seats are all used, the price will go up and stay at $33/year.

Partner – Microsoft – NPI EA (cat = Spring Boot)
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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.

Partner – Orkes – NPI EA (cat = Spring)
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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.

Partner – Orkes – NPI EA (tag = Microservices)
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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.

eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
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The Apache HTTP Client is a very robust library, suitable for both simple and advanced use cases when testing HTTP endpoints. Check out our guide covering basic request and response handling, as well as security, cookies, timeouts, and more:

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eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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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:

>> Download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
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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:

>> Join Pro and download the eBook

eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

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Course – LS – NPI EA (cat=REST)

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Get started with Spring Boot and with core Spring, through the Learn Spring course:

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Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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Course – Spring Sale 2025 – NPI (All)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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Course – LS – NPI (cat=REST)
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Get started with Spring Boot and with core Spring, through the Learn Spring course:

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Partner – Microsoft – NPI (cat=Spring)
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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.

eBook Jackson – NPI EA – 3 (cat = Jackson)
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