Spring MVC with Swagger Integration: Generating Server Code and Testing with Swagger Codegen

a entrepreneur robot is developing a tutorial with the title spring mvc with swagger integration generating server code and testing with swagger codegen in a class
This blog will teach you how to generate server code for Spring MVC with Swagger Codegen and how to test your RESTful API with Swagger UI.

1. Introduction

In this tutorial, you will learn how to generate server code for Spring MVC with Swagger Codegen and how to test your RESTful API with Swagger UI.

Spring MVC is a popular framework for building web applications and RESTful web services in Java. It provides a model-view-controller architecture that simplifies the development and testing of web applications.

Swagger is an open-source software framework that helps developers design, build, document, and consume RESTful web services. It provides a set of tools and specifications that enable you to describe your API in a standard and human-readable format.

Swagger Codegen is one of the tools that Swagger offers. It allows you to generate server and client code for your API in different languages and frameworks, such as Java, Python, Ruby, Spring Boot, etc.

By using Swagger Codegen, you can save time and effort in creating and maintaining your server code for Spring MVC. You can also use Swagger UI to test and interact with your API in a user-friendly way.

Are you ready to get started? Let’s begin by learning more about Swagger and Swagger Codegen in the next section.

2. What is Swagger and Swagger Codegen?

In this section, you will learn more about Swagger and Swagger Codegen, two of the tools that you will use in this tutorial. You will understand what they are, what they do, and why they are useful for developing and testing your Spring MVC RESTful API.

Swagger is an open-source software framework that helps developers design, build, document, and consume RESTful web services. It provides a set of tools and specifications that enable you to describe your API in a standard and human-readable format. Some of the benefits of using Swagger are:

  • It makes your API easier to understand and use by yourself and others.
  • It allows you to generate interactive documentation and testing tools for your API.
  • It supports multiple languages and frameworks, making your API more portable and interoperable.

Swagger Codegen is one of the tools that Swagger offers. It allows you to generate server and client code for your API in different languages and frameworks, such as Java, Python, Ruby, Spring Boot, etc. Some of the benefits of using Swagger Codegen are:

  • It saves you time and effort in creating and maintaining your server code for Spring MVC.
  • It ensures that your server code is consistent with your API specification.
  • It allows you to customize and extend your server code according to your needs.

As you can see, Swagger and Swagger Codegen are powerful and versatile tools that can help you develop and test your Spring MVC RESTful API. In the next section, you will learn how to generate server code for Spring MVC with Swagger Codegen.

2.1. Swagger

Swagger is an open-source software framework that helps developers design, build, document, and consume RESTful web services. It provides a set of tools and specifications that enable you to describe your API in a standard and human-readable format.

One of the core components of Swagger is the Swagger Specification, which is a language-agnostic format for defining the structure and behavior of your API. The Swagger Specification uses JSON or YAML to describe the following aspects of your API:

  • The available endpoints and the HTTP methods they support.
  • The parameters and responses for each endpoint.
  • The data models and schemas for the request and response bodies.
  • The authentication and authorization mechanisms for your API.
  • The metadata and documentation for your API.

By using the Swagger Specification, you can create a Swagger Contract for your API, which is a single source of truth that defines how your API works and what it expects from the consumers. The Swagger Contract can be used to generate various artifacts and tools for your API, such as:

  • Swagger Editor: A web-based editor that allows you to write and validate your Swagger Contract.
  • Swagger UI: A web-based interface that displays your Swagger Contract and allows you to interact with your API.
  • Swagger Codegen: A tool that generates server and client code for your API in different languages and frameworks.
  • Swagger Hub: A cloud-based platform that allows you to manage and collaborate on your Swagger Contracts.

As you can see, Swagger is a powerful and versatile framework that can help you design, build, document, and consume your RESTful web services. In the next section, you will learn more about Swagger Codegen, the tool that you will use to generate server code for Spring MVC.

2.2. Swagger Codegen

Swagger Codegen is a tool that generates server and client code for your API in different languages and frameworks, such as Java, Python, Ruby, Spring Boot, etc. It uses your Swagger Contract as the input and produces the code that implements your API specification.

Some of the benefits of using Swagger Codegen are:

  • It saves you time and effort in creating and maintaining your server code for Spring MVC.
  • It ensures that your server code is consistent with your API specification.
  • It allows you to customize and extend your server code according to your needs.

To use Swagger Codegen, you need to have a valid Swagger Contract for your API. You can create one using the Swagger Editor, which is a web-based editor that allows you to write and validate your Swagger Contract. You can also import an existing Swagger Contract from a file or a URL.

Once you have your Swagger Contract, you can use the Swagger Codegen CLI, which is a command-line interface that allows you to generate server and client code for your API. You can also use the Swagger Codegen Online, which is a web-based service that allows you to generate server and client code for your API without installing anything.

In this tutorial, you will use the Swagger Codegen CLI to generate server code for Spring MVC. You will learn how to install and use the Swagger Codegen CLI in the next section.

3. How to Generate Server Code for Spring MVC with Swagger Codegen?

In this section, you will learn how to generate server code for Spring MVC with Swagger Codegen. You will use the Swagger Codegen CLI, which is a command-line interface that allows you to generate server and client code for your API in different languages and frameworks.

To use the Swagger Codegen CLI, you need to have the following prerequisites:

  • A valid Swagger Contract for your API. You can create one using the Swagger Editor or import an existing one from a file or a URL.
  • A Java runtime environment (JRE) version 8 or higher installed on your machine.
  • The Swagger Codegen CLI jar file downloaded from the Swagger Codegen GitHub repository.

Once you have the prerequisites, you can follow these steps to generate server code for Spring MVC with Swagger Codegen:

  1. Open a terminal or command prompt and navigate to the directory where you have the Swagger Codegen CLI jar file.
  2. Run the following command to generate server code for Spring MVC with the spring generator option:
    3. java -jar swagger-codegen-cli.jar generate -i  -l spring -o
  3. This command will generate a Maven project with the server code for Spring MVC in the output directory that you specified. The project will have the following structure:
    4. ├── pom.xml
├── README.md
├── src
│   ├── main
│   │   ├── java
│   │   │   └── io
│   │   │       └── swagger
│   │   │           ├── api
│   │   │           │   ├── ApiUtil.java
│   │   │           │   ├── .java
│   │   │           │   └── .java
│   │   │           ├── configuration
│   │   │           │   ├── HomeRedirectFilter.java
│   │   │           │   ├── SwaggerDocumentationConfig.java
│   │   │           │   └── WebMvcConfiguration.java
│   │   │           └── model
│   │   │               └── .java
│   │   └── resources
│   │       ├── application.properties
│   │       └── logback.xml
│   └── test
│       └── java
│           └── io
│               └── swagger
│                   ├── api
│                   │   └── .java
│                   └── configuration
│                       └── TestConfiguration.java
└── swagger.json
  4. The generated project will have the following features:
    • The pom.xml file will contain the dependencies and plugins for building and running the project with Maven.
    • The README.md file will contain the instructions on how to build and run the project.
    • The src/main/java/io/swagger/api directory will contain the API controllers, exception handlers, and utility classes for your API endpoints.
    • The src/main/java/io/swagger/configuration directory will contain the configuration classes for the Spring MVC framework, the Swagger UI, and the home redirect filter.
    • The src/main/java/io/swagger/model directory will contain the data models and schemas for your API request and response bodies.
    • The src/main/resources directory will contain the application properties and the logging configuration files.
    • The src/test/java/io/swagger/api directory will contain the unit tests for your API controllers.
    • The src/test/java/io/swagger/configuration directory will contain the test configuration class for the Spring MVC framework.
    • The swagger.json file will contain the Swagger Contract for your API.

Congratulations! You have successfully generated server code for Spring MVC with Swagger Codegen. In the next section, you will learn how to test your Spring MVC RESTful API with Swagger Codegen.

3.1. Prerequisites

Before you can generate server code for Spring MVC with Swagger Codegen, you need to have the following prerequisites:

  • A valid Swagger Contract for your API. You can create one using the Swagger Editor or import an existing one from a file or a URL.
  • A Java runtime environment (JRE) version 8 or higher installed on your machine.
  • The Swagger Codegen CLI jar file downloaded from the Swagger Codegen GitHub repository.

If you don’t have these prerequisites, you can follow the links provided to download and install them. You can also refer to the official documentation of Swagger Codegen for more details and guidance.

Once you have the prerequisites, you are ready to generate server code for Spring MVC with Swagger Codegen. In the next section, you will learn how to use the Swagger Codegen CLI to generate the server code.

3.2. Steps

In this section, you will learn how to use the Swagger Codegen CLI to generate server code for Spring MVC with Swagger Codegen. You will follow these steps:

  1. Open a terminal or command prompt and navigate to the directory where you have the Swagger Codegen CLI jar file.
  2. Run the following command to generate server code for Spring MVC with the spring generator option:
    3. java -jar swagger-codegen-cli.jar generate -i  -l spring -o
  3. This command will generate a Maven project with the server code for Spring MVC in the output directory that you specified. The project will have the following structure:
    4. ├── pom.xml
├── README.md
├── src
│   ├── main
│   │   ├── java
│   │   │   └── io
│   │   │       └── swagger
│   │   │           ├── api
│   │   │           │   ├── ApiUtil.java
│   │   │           │   ├── .java
│   │   │           │   └── .java
│   │   │           ├── configuration
│   │   │           │   ├── HomeRedirectFilter.java
│   │   │           │   ├── SwaggerDocumentationConfig.java
│   │   │           │   └── WebMvcConfiguration.java
│   │   │           └── model
│   │   │               └── .java
│   │   └── resources
│   │       ├── application.properties
│   │       └── logback.xml
│   └── test
│       └── java
│           └── io
│               └── swagger
│                   ├── api
│                   │   └── .java
│                   └── configuration
│                       └── TestConfiguration.java
└── swagger.json
  4. The generated project will have the following features:
    • The pom.xml file will contain the dependencies and plugins for building and running the project with Maven.
    • The README.md file will contain the instructions on how to build and run the project.
    • The src/main/java/io/swagger/api directory will contain the API controllers, exception handlers, and utility classes for your API endpoints.
    • The src/main/java/io/swagger/configuration directory will contain the configuration classes for the Spring MVC framework, the Swagger UI, and the home redirect filter.
    • The src/main/java/io/swagger/model directory will contain the data models and schemas for your API request and response bodies.
    • The src/main/resources directory will contain the application properties and the logging configuration files.
    • The src/test/java/io/swagger/api directory will contain the unit tests for your API controllers.
    • The src/test/java/io/swagger/configuration directory will contain the test configuration class for the Spring MVC framework.
    • The swagger.json file will contain the Swagger Contract for your API.

That’s it! You have successfully generated server code for Spring MVC with Swagger Codegen. In the next section, you will learn how to test your Spring MVC RESTful API with Swagger Codegen.

4. How to Test Your Spring MVC RESTful API with Swagger Codegen?

In this section, you will learn how to test your Spring MVC RESTful API with Swagger Codegen. You will use the Swagger UI, which is a web-based interface that displays your Swagger Contract and allows you to interact with your API.

Some of the benefits of using Swagger UI are:

  • It provides a visual and interactive documentation of your API.
  • It allows you to explore and test your API endpoints without writing any code.
  • It supports multiple authentication and authorization mechanisms for your API.
  • It helps you debug and troubleshoot your API issues.

To use Swagger UI, you need to have the following prerequisites:

  • A valid Swagger Contract for your API. You can create one using the Swagger Editor or import an existing one from a file or a URL.
  • A Maven project with the server code for Spring MVC generated by Swagger Codegen. You can create one by following the steps in the previous section.

Once you have the prerequisites, you can follow these steps to test your Spring MVC RESTful API with Swagger UI:

  1. Open a terminal or command prompt and navigate to the directory where you have the Maven project.
  2. Run the following command to build and run the project with Maven:
    3. mvn clean package spring-boot:run
  3. This command will compile and package the project and start the Spring Boot application on the default port 8080.
  4. Open a web browser and navigate to the following URL:
    5. http://localhost:8080/swagger-ui.html
  5. This URL will display the Swagger UI with your Swagger Contract and your API endpoints.
  6. You can click on each endpoint to expand its details and parameters. You can also click on the Try it out button to execute the endpoint and see the response.
  7. You can use the Authorize button to provide the authentication and authorization credentials for your API, if required.
  8. You can use the Models button to view the data models and schemas for your API request and response bodies.

Congratulations! You have successfully tested your Spring MVC RESTful API with Swagger UI. In the next section, you will learn how to conclude your tutorial and provide some additional resources for the readers.

4.1. Running the Server

In this section, you will learn how to run the server code for Spring MVC that you generated with Swagger Codegen. You will use Maven, which is a software project management and comprehension tool that can help you build and run your project.

To run the server code for Spring MVC, you need to have the following prerequisites:

  • A Maven project with the server code for Spring MVC generated by Swagger Codegen. You can create one by following the steps in the previous section.
  • A Maven command-line tool installed on your machine. You can download and install it from the Maven official website.

Once you have the prerequisites, you can follow these steps to run the server code for Spring MVC:

  1. Open a terminal or command prompt and navigate to the directory where you have the Maven project.
  2. Run the following command to build and run the project with Maven:
    3. mvn clean package spring-boot:run
  3. This command will compile and package the project and start the Spring Boot application on the default port 8080.
  4. You can verify that the server is running by opening a web browser and navigating to the following URL:
    5. http://localhost:8080
  5. This URL will redirect you to the Swagger UI, which you will use to test your API in the next section.

That’s it! You have successfully run the server code for Spring MVC with Maven. In the next section, you will learn how to use the Swagger UI to test your Spring MVC RESTful API.

4.2. Using the Swagger UI

In this section, you will learn how to use the Swagger UI to test your Spring MVC RESTful API that you generated with Swagger Codegen. You will use the Swagger UI, which is a web-based interface that displays your Swagger Contract and allows you to interact with your API.

The Swagger UI provides a visual and interactive documentation of your API. You can explore and test your API endpoints without writing any code. You can also use the Swagger UI to provide the authentication and authorization credentials for your API, if required. You can also view the data models and schemas for your API request and response bodies.

To use the Swagger UI, you need to have the following prerequisites:

  • A valid Swagger Contract for your API. You can create one using the Swagger Editor or import an existing one from a file or a URL.
  • A Maven project with the server code for Spring MVC generated by Swagger Codegen. You can create one by following the steps in the previous section.
  • A Spring Boot application running on the default port 8080. You can start the application by following the steps in the previous section.

Once you have the prerequisites, you can follow these steps to use the Swagger UI to test your Spring MVC RESTful API:

  1. Open a web browser and navigate to the following URL:
    2. http://localhost:8080/swagger-ui.html
  2. This URL will display the Swagger UI with your Swagger Contract and your API endpoints.
  3. You can click on each endpoint to expand its details and parameters. You can also click on the Try it out button to execute the endpoint and see the response.
  4. You can use the Authorize button to provide the authentication and authorization credentials for your API, if required.
  5. You can use the Models button to view the data models and schemas for your API request and response bodies.

That’s it! You have successfully used the Swagger UI to test your Spring MVC RESTful API. You can use the Swagger UI to explore and test other endpoints and features of your API. You can also modify your Swagger Contract and regenerate your server code with Swagger Codegen if you want to make any changes to your API.

In the next section, you will learn how to conclude your tutorial and provide some additional resources for the readers.

5. Conclusion

In this tutorial, you have learned how to generate server code for Spring MVC with Swagger Codegen and how to test your RESTful API with Swagger UI. You have used the following tools and concepts:

  • Swagger: An open-source software framework that helps developers design, build, document, and consume RESTful web services.
  • Swagger Specification: A language-agnostic format for defining the structure and behavior of your API.
  • Swagger Contract: A single source of truth that defines how your API works and what it expects from the consumers.
  • Swagger Codegen: A tool that generates server and client code for your API in different languages and frameworks.
  • Swagger UI: A web-based interface that displays your Swagger Contract and allows you to interact with your API.
  • Spring MVC: A popular framework for building web applications and RESTful web services in Java.
  • Maven: A software project management and comprehension tool that can help you build and run your project.

By using Swagger Codegen, you have saved time and effort in creating and maintaining your server code for Spring MVC. You have also used Swagger UI to test and interact with your API in a user-friendly way.

You have completed this tutorial and learned how to generate server code and test your RESTful API with Swagger Codegen. We hope you enjoyed this tutorial and found it useful. If you want to learn more about Swagger and Swagger Codegen, you can visit the following resources:

Thank you for reading this tutorial and happy coding!

Leave a Reply

Your email address will not be published. Required fields are marked *

Related Posts