Date sample rev.3 (Java 8 ver.)

gistfile1.txt

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;


/**
 * Created by vine on 15. 12. 29..
 */
public class Main {
    public static void main(String args[]) {
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");

        LocalDate targetDate = LocalDate.parse("20160102", formatter)
                .minusMonths(1)
                .withDayOfMonth(1);
        System.out.println(targetDate);

        List<String> days = IntStream
                .range(0, targetDate.lengthOfMonth())
                .mapToObj(i -> targetDate.plusDays(i).format(formatter))
                .collect(Collectors.toList());

        System.out.println(days);
    }
}