Integrating GlassFish with OpenAPI for documenting and testing Java APIs

17 Sep 2023

In today’s software development landscape, documenting and testing APIs are crucial steps towards building robust and scalable applications. OpenAPI, formerly known as Swagger, is a widely adopted standard for documenting RESTful APIs. GlassFish, on the other hand, is a popular Java application server that provides a runtime environment for Java applications.

By integrating GlassFish with OpenAPI, developers can easily generate comprehensive documentation for their Java APIs and also leverage the powerful testing capabilities provided by OpenAPI tools. In this blog post, we will explore how to integrate GlassFish with OpenAPI and demonstrate how it can benefit your Java API development process.

Prerequisites:

GlassFish Installed
OpenAPI Specification (OAS) Document for your Java API

Step 1: Installing OpenAPI Tools

To begin, we need to install the OpenAPI tools that will be used to generate the API documentation and perform testing. OpenAPI Tools provides a command-line interface (CLI) for working with OpenAPI specifications.

npm install --global @openapitools/openapi-generator-cli

Step 2: Generating API Documentation

Once the OpenAPI tools are installed, we can generate the API documentation for our Java API. Assuming you already have an OpenAPI Specification document (in YAML or JSON format), run the following command:

openapi-generator generate -i api-spec.yaml -g html2 -o docs

This command generates HTML-based documentation based on the provided OpenAPI Specification document. The -i flag specifies the input file (your OpenAPI spec), the -g flag specifies the generator, and the -o flag specifies the output directory for the generated documentation.

Step 3: Deploying API Documentation on GlassFish

Now that we have the API documentation generated, we can deploy it on GlassFish to make it accessible through the web browser. Follow these steps to deploy the documentation:

Start GlassFish by running asadmin start-domain
Deploy the generated documentation by running asadmin deploy docs

GlassFish will now host the API documentation, which can be accessed using the URL http://localhost:8080/docs.

Step 4: Testing Java APIs using OpenAPI

One of the key benefits of integrating GlassFish with OpenAPI is the ability to perform automated testing of your Java APIs. OpenAPI Tools provides a openapi-generator CLI command to generate a client library based on your OpenAPI Specification, which you can use for testing your APIs.

openapi-generator generate -i api-spec.yaml -g java -o api-client

This command generates a Java client library based on your OpenAPI specification. You can then use this library in your test scenarios to make requests to your Java APIs.

Conclusion

Integrating GlassFish with OpenAPI empowers Java developers to easily generate comprehensive API documentation and perform automated testing of their APIs. By following the steps outlined in this blog post, you can streamline your Java API development process and ensure the quality and reliability of your APIs. Start leveraging the power of OpenAPI and GlassFish today for efficient API development.

#APIs #OpenAPI #GlassFish