OAuth 2.0 Authorization Code Grant Type Using Salesforce

As I mentioned in my previous post what is Oauth 2.0 authorization code grant type.

To implement this authorization in Salesforce we have to perform the following steps”

• Implement apex code to send first request
  String client_id = '*******************';
String client_Secret = '************';
Blob headerValue = Blob.valueOf(client_id + ':' + client_Secret);
Http http = new Http();
HttpRequest req = new HttpRequest();
req.setEndpoint('*********');
req.setMethod('POST');
String authorizationHeader = 'Basic ' + EncodingUtil.base64Encode(headerValue);
req.setHeader('Authorization',authorizationHeader);
req.setHeader('Content-Type','application/x-www-form-urlencoded');
String callBackCode = ‘**************’;
req.setHeader('Accept','application/json');
req.setBody('grant_type=authorization_code&code=' + callBackCode + '&redirect_uri=*****');
• This code sends a request to the API server. It will be processed and redirected to the URL present in the query string ‘redirect_uri’.
• This Uri contains an access token and related details. To achieve this in salesforce we need to create sites.
• Sites use the Visual force page which will be opened when the URL got hit. On that VF page, we access the access token.
• Now we can store it and use it anywhere we need and refresh the token anytime whenever we need