Box API : How to Regenerate Access Token from Refresh Token

Box and Salesforce can be integrated to store files on box and link them with salesforce records. You can also write apex script to extract files or attachments from Salesforce and upload it into box folder.

For basic understanding on how to generate access token from box, refer below URL:
Box and Salesforce Integration

Whenever we perform handshake with box using OAuth, box returns access token along with refresh token. Below is sample JSON response for access token:

{
"access_token": "h91xxxxxxxxxxxxxxxxxxxx8",
"expires_in": 4012,
"restricted_to": [],
"refresh_token": "bxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxM",
"token_type": "bearer"
}

here expires_in specifies the duration for which this access token is valid. After this duration, user will recieve 401 error so we need to regenerate the access token using refresh token.

Below is apex code which can be used to regenerate new access token and refresh token. In order to regenerate you need clientid, client secret and refresh token.

Above mentioned code is self explainatory.


Hope this help!!!