Read data from Google Spreadsheet without authentication using Java

Google Spreadsheets provides a way to create, edit, save spreadsheets online.
The Google Sheets API (formerly called the Google Spreadsheets API) lets you develop client applications that read and modify worksheets and data in Google Sheets.
Read More about Sheets API

Let's see how to use this API to read data from Spreadsheet, here i am going to use Spreadsheet version 3.0 , if this link doesn't work then check on GitHub , from here you will get  client library for all Google APIs