This document discusses how to create a custom connector in MuleSoft to consume a REST API. It provides steps to install the Mule DevKit plugin in AnyPoint Studio, create an AnyPoint connector project, modify the template Java class to call the Weather API, build and install the connector, create a sample Mule project and flow using the custom connector, and test the application by calling the REST endpoint. The goal is to demonstrate how to develop a custom connector in MuleSoft to integrate with any underlying system exposed through an API.

1. By Ramakrishna Narkedamilli

2. Overview:
MuleSoft is a popular ESB technology to integrate Different on-premise and cloud
applications for data exchange. It provides powerful toll called Mule DevKit to enable
the option to develop Custom connectors. Using this we can create connector for any
underlying system using there exposing API services.
In this presentation will going to see
 How to install Mule Devkit in Mule Anypoint studio.
 Creating sample connector to consume Rest API
 Build and Install the Custom Connector.
 Creating sample Mule project and flow by using the Sample custom connector.
 Run and Testing the application.

3. Install Mule DevKit in AnyPoint Studio:
Below are the steps to be followed to install the Mule DevKit in Anypoint studio.
 Click Help  Install New Software  Select the “Anypoint Addons Update Site -
http://studio.mulesoft.org/r3/addons/beta”
 Select AnyPoint DevKit Plugin  Click Next and finish.

4. Create Sample Custom Connector :
 Click File  New  Other  Mule  AnyPoint Connector project.
 Enter the Connector name and click on finish. Now Anypoint connector project is
created.

5.  Open the Java class available under src/main/java. You can see Java class with
some template methods and now we need to edit as required.
 So will modify the methods to consume the rest api ( Weather api service to get
the weather for a city). Its simple line of code.
 For this replace the custom processor method with below code
@Processor
@RestCall(uri =
"http://api.openweathermap.org/data/2.5/weather?q={cityName}", method =
HttpMethod.GET)
public abstract Object getWeatherByCity(@RestUriParam("cityName") String
cityName) throws IOException;
 Class will show error and change the class type as abstract.
 Now Custom connector code is ready to build and install.

6. Build and Install the custom connector:
 Right click on Custom Connector project  AnyPoint Connector  Install or
Update.
 It will build and install the Custom connector in case of no errors. Based on studio
version It will ask permission to install or for latest version it will install
automatically. You may required to studio restart based on Studio version.

7. Create Sample Project for Testing:
 Click File  New  Mule project.
 Add Http inbound endpoint To trigger the service.
 Now your able to see Custom connector in the custom connectors list.
 Configure SampleCustom global connector by providing required values.
 Add SampleCustom outbound endpoint by referring to Global connector and
provide required values

8.  Add logger component to print some loggers
 Finally flow will look like below
 Now we need to test the application.

9. Run and Test the application:
 Right click on Project  Run as  Mule application.
 Open the browser and hit the URL http://localhost:8081/getWeatherByCity
 It showed the correct response get out from Connector.
 For more details on Custom connector development refer the Mule
documentation
https://docs.mulesoft.com/anypoint-connector-devkit/v/3.7/

10. THANKS YOU
By Ramakrishna Narkedamilli