Converting JSON to excel and from excel to JSON

Question

I have a JSON like the following

{
"activate": {
    "title": "Activation",
    "messages": {
        "success": "<strong>Your user account has been activated.</strong> 
     Please ",
        "error": "<strong>Your user could not be activated.</strong> Please 
   use the registration form to sign up."
    }
  }
}

I want to convert it to excel sheet like the following

Row 1 - (col1)activate.title (col2) Activation
Row 2 - (col1)activate.messages.success (col2) Your user account...

Like this until the end.

If the user edits the excel sheet, and if the user adds some rows, I want to convert it back to json with that updates. Is it possible or there any easy ways to do this in java