Building APIs From Scratch with WSO2 API Manager

Joseph Fonseka & Madusanka Premaratne

Building APIs from Scratch with WSO2

API Manager

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About the Presenters

๏ Joseph Fonseka Joseph joined WSO2 in September 2013. He is a Senior Tech Lead in the WSO2 API Manager team where he focuses on improving the UX of the API Manager. In addition to his product development efforts he is also a contributor to the Sahana and OpenEvsys open-source projects. He is also a FOSS advocate.

๏ Madusanka Premaratne Madusanka is an Associate Software Engineer at WSO2 where he is a part of API Manager Team. Prior to joining WSO2, Madusanka worked at CodeGen Int as a Software Engineer. He holds a first class bachelor’s degree in Information and Communication Technology from University of Jaffna, Sri Lanka.

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Introduction

๏ This is an introductory webinar on how to develop APIs from conceptual stage to a production ready API.

๏ We will look at how WSO2 API manager and other community based tooling can help to develop an API quickly.

๏ In this session we will be focusing on RESTful APIs.

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API Development Flow

Design

Test Implement

Publish

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API Design

๏ Having a good API Design can save you lot of maintenance effort and promote API adoption.

๏ Use Swagger 2.0 to document API.http://swagger.io/

๏ Use Swagger editor to design your API.http://editor.swagger.io/#/

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Example API

๏ Lets develop PizzaShack API which allows you to order pizza.

Resource URL HTTP Method

1 /menu GET

2 /order POST

3 /order/{orderId} GET

4 /delivery GET

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API Implementation

๏ In this section we will discuss how to create a web service using existing swagger v2.0 file and deploy it on a web server.

๏ Required Tools๏ Java 7๏ Apache Maven 3.0.3 or greater๏ Swagger Codegen

(Go to https://github.com/swagger-api/swagger-codegen)

๏ IntelliJ IDEA

Continued

๏ Commands to run๏ mvn package ๏ java -jar <dir>/target/swagger-codegen-cli.jar generate -l jaxrs

-i <dir>/<swagger-file>.json -o <output_dir>

๏ Open the created project using an IDE๏ Implement your logic๏ Build and deploy the service๏ Implement the API by giving deployed service’s

endpoint

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API Publishing

๏ In this section we will discuss about API publishing and invoking published API through WSO2 API Manager

๏ Before publishing,

๏ Set the initial/required configurations ๏ Select Gateway Environments๏ Fill the Business Information

๏ After Publishing,๏ Visit API Store๏ Subscribe to API and generate Access Token๏ Invoke the API using API Console

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Testing with SOAP UI

๏ In this section we will discuss how to test the created APIs with SoapUI

๏ Soap UI can be used to test the created APIs๏ How to use SoapUI๏ Sample SoapUI Project

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Creating a Client for API

๏ Use swagger-codegen to generate client stubs.

๏ Swagger-Js can be use as a javascript client to swagger enabled APIs.

https://github.com/swagger-api/swagger-js

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