Integrating Salesforce with a HTTP Rest API service

In one of my previous posts, I created a Rest API endpoint using a Spring based java application and deployed it to Heroku. Now that we have an endpoint that returns json output, I would like to create an integration to it from my Salesforce org.

If you are interested in how I built the rest api end point, please see below steps -

• Setting up a Spring rest api web app
• Deploying my Spring application on Heroku

To integrate this in Salesforce, I will create an Apex class to do the callout. The http callout will call the rest api and get the response. For this demo, all i am doing is getting the output and writing it to system debug. But hopefully this will show how the same can be done in a real business usecase.

• First lets add the API endpoint url as a remote site. This will tell Salesforce that this is a valid endpoint to call. This is done in Setup -> Security Controls -> Remote Site Settings.

• Now that the site is added, lets create the Apex callout class. I am doing this in my Force IDE - 

• Now lets build out the callout in the class. Apex has following classes that allow us to make these http calls with appropriate request and response details - Http, HttpRequest, HttpResponse. Please see below example class -

• Now for testing this, all i am doing is writing out the response body and status into System.debug. In a real integration, you would parse the response and use it. Lets test it out via an Anonymous piece of code below -

 

  Awesome, as you can see the callout was successful and we got back the json response body. For parsing the json response, there are couple of options. We can either deserialize the response to a class and use that class OR use the JSONParser class methods. I will write a different post showing how this can be done. Till then have fun!