Function works inside Main method but doesn't work in another class

Question

I am facing this weird issue. I have written following function which fetches tweets of a user between specified dates:

List<Tweet> tweetlist =  TweetManager.getTweets("arynewsofficial", fromdate, todate, null);

The function works absolutely fine inside main method and returns collection of tweets. However, when I add this line of code in another function inside some other class, application doesnt return anything. Rather, it hangs. Here is my class in which I have added my function:

public class NewsCollector {        
    public List<String> collectTweets(String stockdate[], int noofpastimpacts) 
           throws IOException
    {
        try
        {
            int year= Integer.parseInt(stockdate[0]);
            int month= Integer.parseInt(stockdate[1]);
            int day= Integer.parseInt(stockdate[2]);
            List<String> tweetstext = new ArrayList<String>();

            LocalDate currentdate = LocalDate.of(year, month, day);
            LocalDate datefromdate = currentdate.minusDays(noofpastimpacts+1);

            String fromdate= datefromdate.getYear()+ "-" + 
                             datefromdate.getMonthValue() + "-" + 
                             datefromdate.getDayOfMonth();
            LocalDate datetodate = datefromdate.plusDays(noofpastimpacts);

            String todate = datetodate.getYear() + "-" + 
                            datetodate.getMonthValue() + "-" +
                            datetodate.getDayOfMonth();

            List<Tweet> tweetlist =  
                    TweetManager.getTweets("arynewsofficial", fromdate, todate, null);

            List<String[]> data = new ArrayList<String[]>();
            data.add(new String[] {"Text", "Date","Sentiment"});

            for(Tweet tweety: tweetlist)
            {
                data.add(new String[] { tweety.getText(), 
                                tweety.getDate().toString(),
                                "0"});
                tweetstext.add(tweety.getText());
            }

            String csv = "D:/Tweets/"+fromdate+".csv";
            CSVWriter writer = new CSVWriter(new FileWriter(csv));

            writer.writeAll(data);
            writer.close();

            System.out.print("Total Tweets Retreived: "+tweetlist.size() );
            return tweetstext;
        }
        catch(Exception e)
        {
            System.out.println(e.getMessage());
            return null;

        }
    }
}

Answer 1

Is NewsCollector supposed to be used as an object? It doesn't look like that, so you may want to make your method static.