# Adding a new API to the core app

# Prerequisites

  • Java 8

  • maven

# Overview

This guide will take you through adding a new REST API to the Entando core app. In some cases it is better to add new APIs to the core rather than creating a new microservice. Some example cases where adding new APIs to the core is recommended are:

  • When extending or adding functionality to the WCMS

  • When you have a simple use case requiring persistence that is specific to only the application you’re working within

  • When exposing configurations that are needed by the portal-ui during page rendering

  • For small changes that don’t warrant a full stand-alone microservice

You can build widgets and micro frontends that take advantage of these APIs in the same way that your micro-frontends can invoke APIs exposed by other services.

# Tutorial

Creating a controller and services

  1. Create a new java package in the project using your favorite IDE at the path org.entando.training.

  2. Under that package add packages for controllers and services.

  3. Create a class called DemoController.java from the training package into the controllers package.

    • This is a normal Spring rest controller and it will be discovered by annotations.
  4. Copy DemoService.java from the training package into the services package.

    • This is a normal Spring service that will be autowired into the controller. The data in this service is hardcoded but this is where you can wire in external services or other parts of the Entando architecture to fetch the data.
  5. Copy commonConfig.xml to src/main/resources/spring/aps/managers.

    • The goal is to enable package scanning for annotation driven spring services. This includes the package scan for your package defined above. If you want to scan another package, then you need to add another path to this file. This is the only spring XML you will need to change if you want to build annotation driven beans in Entando.

    • See also web.xml for deeper details.

  6. Review the code and annotations in the controller to understand how the APIs are protected and integrated.

  7. @RestAccessControl is a custom Entando annotation that can be used to restrict APIs by role.

    • The rest of the annotations are normal Spring annotations.
  8. Restart your app using jetty.

    • if you get an error add the entries below to src/main/conf/systemParams.properties This is temporary

      # Parameters for Argon2 algorithm encryption
  9. Go to Swagger

  10. Find the demo-controller and try your new endpoints out using swagger