How to get public Google Spreadsheet data using Google Spreadsheet API Java library without authentication

Question

-what I want to do

I would like to get data from Google Spreadsheet using Google Spreadsheet API Java library without authentication. The Google Spreadsheet is published with public. I would like to use the following method: com.google.gdata.data.spreadsheet.CustomElementCollection

-Issue

CustomElementCollection return collect data with authentication. But CustomElementCollection return null without authentication.

As listEntry.getPlainTextContent() shows data, so I think I should be able to get the data in any ways.

-Source code attached

With authentication: Auth.java

import java.net.URL;
import java.util.List;
import com.google.gdata.client.spreadsheet.ListQuery;
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.data.spreadsheet.SpreadsheetEntry;
import com.google.gdata.data.spreadsheet.WorksheetEntry;

public class Auth {
    public static void main(String[] args) throws Exception{
        String applicationName = "AppName";
        String user = args[0];
        String pass = args[1];
        String key = args[2];
        String query = args[3];

        SpreadsheetService service = new SpreadsheetService(applicationName);
        service.setUserCredentials(user, pass); //set client auth 

        URL entryUrl = new URL("http://spreadsheets.google.com/feeds/spreadsheets/" + key);
        SpreadsheetEntry spreadsheetEntry = service.getEntry(entryUrl, SpreadsheetEntry.class);
        WorksheetEntry worksheetEntry = spreadsheetEntry.getDefaultWorksheet();

        ListQuery listQuery = new ListQuery(worksheetEntry.getListFeedUrl());
        listQuery.setSpreadsheetQuery( query );

        ListFeed listFeed = service.query(listQuery, ListFeed.class);
        List<ListEntry> list = listFeed.getEntries();
        for( ListEntry listEntry : list )
        {
            System.out.println( "content=[" + listEntry.getPlainTextContent() + "]");
            CustomElementCollection elements = listEntry.getCustomElements();
            System.out.println(
                    " name=" + elements.getValue("name") + 
                    " age="  + elements.getValue("age") );
        }
    }
}

Without authentication: NoAuth.java

import java.net.URL;
import java.util.List;
import com.google.gdata.client.spreadsheet.FeedURLFactory;
import com.google.gdata.client.spreadsheet.ListQuery;
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.data.spreadsheet.WorksheetEntry;
import com.google.gdata.data.spreadsheet.WorksheetFeed;

public class NoAuth {
    public static void main(String[] args) throws Exception{
        String applicationName = "AppName";
        String key = args[0];
        String query = args[1];

        SpreadsheetService service = new SpreadsheetService(applicationName);

        URL url = FeedURLFactory.getDefault().getWorksheetFeedUrl(key, "public", "basic");

        WorksheetFeed feed = service.getFeed(url, WorksheetFeed.class);
        List<WorksheetEntry> worksheetList = feed.getEntries();
        WorksheetEntry worksheetEntry = worksheetList.get(0);

        ListQuery listQuery = new ListQuery(worksheetEntry.getListFeedUrl());
        listQuery.setSpreadsheetQuery( query );

        ListFeed listFeed = service.query( listQuery, ListFeed.class );
        List<ListEntry> list = listFeed.getEntries();
        for( ListEntry listEntry : list )
        {
            System.out.println( "content=[" + listEntry.getPlainTextContent() + "]");
            CustomElementCollection elements = listEntry.getCustomElements();
            System.out.println(
                    " name=" + elements.getValue("name") + 
                    " age="  + elements.getValue("age") );
        }
    }
}

Google Spreadsheet:

https://docs.google.com/spreadsheet/pub?key=0Ajawooo6A9OldHV0VHYzVVhTZlB6SHRjbGc5MG1CakE&output=html

-Result

Without authentication

　　　content=[age: 23] 　　　name=null age=null

With authentication

　　　content=[age: 23] 　　　name=Taro age=23

Please let me know the useful information to avoid the issue.

Answer 1

I don't know why it works like that, but when you don't access request with credentials, you are not able to retrieve cells via:

CustomElementCollection elements = listEntry.getCustomElements();
System.out.println(" name=" + elements.getValue("name") + " age="  + elements.getValue("age") );

I've tested it and I have found only this way to retrieve data:

List<ListEntry> list = listFeed.getEntries();
for (ListEntry row : list) {
    System.out.println(row.getTitle().getPlainText() + "\t"
            + row.getPlainTextContent());
}

It prints:

Taro    age: 23
Hanako  age: 16

As you see, you should parse text and retrieve age from raw String.