Creating a REST API

Here, we will learn to create a Representational State Transfer (REST) API, that is, how RESTful services are created in WSO2EI. We create them from the Developer Studio dashboard by following these steps:

1. Click on REST API:

1. Choose Create A New API Artifact and click on Next.
2. Add the following information:
   • Name: Name of the API; here, we will set it to my1stapi
   • Context: This is the root context our services will have, for example, my1stapi. Thus, when calling the API, the URL will look like http://localhost:8280/my1stapi. It must start with /.
   • Host name: We can leave it blank. It is used to filter the host that can invoke this API; if it is blank, everyone can call it.
   • Port: This is used if we need to bind the API to a specific port; here, we leave it blank.
   • Save location: Choose an ESB project to save it. Here, we choose My1stESBProject.

1. Click on Finish, and the API structure will be added to the project. It will be placed in the My1stESBProject project in the project explorer in the path:

1. If we double-click on the my1stapi.xml file, the API editor will open and will look like this:

1. Now we are ready to implement our API functionality. API works the same way as proxy services. They both use in sequence, out sequence, and fault sequence, where logic is implemented.

We will go over RESTful services again later in the book.