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

Extract downloaded zip file in your directory and go to lib folder your_directory...\gdata-samples.java-1.47.1\gdata\java\lib, from there copy Gdata-core-10.jar, Gdata-spreadsheet-30.jar, Google-collect-10-rc1.jar to your project path and add all jar files to project class path

Next Step is create and configure Google Sheet -

First step is to log in  your google account and access Google Sheets

You will see some predefined templates to create new sheet or you can create a blank sheet (Just click on Blank option)

A new sheet opens , provide title and column name (as many as you want) and put some data in cells of each columns

Next step is to publish this spreadsheets, click on File menu and select Publish to web option

 Publish with default settings  (Entire document as WebPage)

 After publishing just copy URL to access published spreadsheet

But we can't use this URL in our java code so change it to a different URL. Copy spreadsheet key from above URL
https://docs.google.com/spreadsheets/d/1G3VABou70MUbRzY4vHgiDME5JW5rfo7lrAr_hZyEawU/pubhtml
and use in this https://spreadsheets.google.com/feeds/list/SPREADSHEET_KEY/default/public/values 

After changes final URL to access spreadsheet feeds looks like this - https://spreadsheets.google.com/feeds/list/1G3VABou70MUbRzY4vHgiDME5JW5rfo7lrAr_hZyEawU/default/public/values

Now see the code to read data (All required jars are mentioned above, add all to project class path)

import java.io.IOException;

import java.net.URL;

import com.google.gdata.client.spreadsheet.SpreadsheetService;
import com.google.gdata.data.spreadsheet.CustomElementCollection;
import com.google.gdata.data.spreadsheet.ListEntry;
import com.google.gdata.data.spreadsheet.ListFeed;
import com.google.gdata.util.ServiceException;

public class PrintSpreadsheet {
    public static void main(String[] args) {
        SpreadsheetService service = new SpreadsheetService("Sheet1");
        try {
            String sheetUrl =
                "https://spreadsheets.google.com/feeds/list/1G3VABou70MUbRzY4vHgiDME5JW5rfo7lrAr_hZyEawU/default/public/values";

            // Use this String as url
            URL url = new URL(sheetUrl);

            // Get Feed of Spreadsheet url
            ListFeed lf = service.getFeed(url, ListFeed.class);

            //Iterate over feed to get cell value
            for (ListEntry le : lf.getEntries()) {
                CustomElementCollection cec = le.getCustomElements();
                //Pass column name to access it's cell values
                String val = cec.getValue("Cell1");
                System.out.println(val);
                String val2 = cec.getValue("Cell2");
                System.out.println(val2);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ServiceException e) {
            e.printStackTrace();
        }
    }
}

And output is -

Cheers :) Happy Learning