Storing date value into MySql

String source="01/03/2014";  
		SimpleDateFormat format = new SimpleDateFormat("dd/MM/yyyy");                       
		java.sql.Date estaDate= new java.sql.Date(format.parse(source).getTime());

Check Validate User

class UserDAO {
     
    public static String[]  getUsers() {
        String [] usernames = new String[] { "sridhar", "senthil", "siva" , "kamal" };
        return usernames;
    }
     
    public static boolean isValidUser(String username) {
         
        String[] users = getUsers();
        boolean isValid = false;
        for (String name : users) {
             
            if ( name.equals(username )) {
                isValid = true;
                break;
            }
        }
         
        return isValid;
         
    }
}
 
 
public class TestLogin {
 
    public static void main(String[] args) {
         
        //success case
        String username1 = "sridhar";
        System.out.println(  username1 + " is a Valid User ? " +  UserDAO.isValidUser(username1));
         
        //failure case
        String username2 = "abc";
        System.out.println(  username2 + " is a Valid User ? " +  UserDAO.isValidUser(username2));
         
    }
}

Date Util

Obtaining Local Date and Time

import java.time.LocalDate;
import java.time.LocalTime;
public class LocalDateTime {
	static LocalDate localDate = LocalDate.now();
	static LocalTime localTime = LocalTime.now();
	public static void main(String[] args){
		System.out.println("The local date is: " +
				localDate);
		System.out.println("The local time is:" +
				localTime);
	}
}

---

DateTimeFormat

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
public class TestDateTimeApi{
	public static void main (String[] args){
		DateTimeFormatter formatter =
				DateTimeFormatter.ofPattern("MM/dd/yyyy");
		LocalDate yearStart = LocalDate.parse("01/01/2014",
				formatter);
		System.out.println("Beginning of year: " +
				yearStart);
	}
}

---

TimeIntervalExamples

import java.time.LocalDate;
import java.time.Month;
import java.time.Period;
import java.time.temporal.ChronoUnit;
import java.util.Calendar;
import java.util.Date;
import java.util.concurrent.TimeUnit;
/**
 *
 * Finding the Interval Between Dates and Times
 *
 */
public class TimeIntervalExamples {
	public static void intervals(){
		LocalDate anniversary = LocalDate.of(2000, Month.NOVEMBER, 11);
		LocalDate today = LocalDate.now();
		Period period = Period.between(anniversary, today);
		System.out.println("Number of Days Difference:" +
				period.getDays());
		System.out.println("Number of Months Difference: " +
				period.getMonths());
		System.out.println("Number of Years Difference: " +
				period.getYears());
	}
	public static void totalsBetween(){
		LocalDate anniversary = LocalDate.of(2000, Month.NOVEMBER, 11);
		LocalDate today = LocalDate.now();
		long yearsBetween = ChronoUnit.YEARS.between(anniversary, today);
		System.out.println("Years between dates: " + yearsBetween);
		long daysBetween = ChronoUnit.DAYS.between(anniversary, today);
		System.out.println("Days between dates:" + daysBetween);
	}
	public static void compareDatesCalendar() {
		// Obtain two instances of the Calendar class
		Calendar cal1 = Calendar.getInstance();
		Calendar cal2 = Calendar.getInstance();
		// Set the date to 01/01/2010:12:00
		cal2.set(2010, 0, 1, 12, 0);
		Date date1 = cal2.getTime();
		System.out.println(date1);
		long mill = Math.abs(cal1.getTimeInMillis() - date1.getTime());
		// Convert to hours
		long hours = TimeUnit.MILLISECONDS.toHours(mill);
		// Convert to days
		Long days = TimeUnit.HOURS.toDays(hours);
		String diff = String.format("%d hour(s) %d min(s)", hours,
				TimeUnit.MILLISECONDS.toMinutes(mill) -
				TimeUnit.HOURS.toMinutes(hours));
		System.out.println(diff);
		diff = String.format("%d days", days);
		System.out.println(diff);
		// Divide the number of days by seven for the weeks
		int weeks = days.intValue() / 7;
		diff = String.format("%d weeks", weeks);
		System.out.println(diff);
	}
	public static void main(String[] args){
		intervals();
		totalsBetween();
		compareDatesCalendar();
	}

Date Comparison

import java.time.LocalDate;
import java.time.Month;
/**
 *
 * Compare Two Dates
 *
 */
public class DateComparisons {
	public static void compareDates(LocalDate ldt1,
			LocalDate ldt2) {
		int comparison = ldt1.compareTo(ldt2);
		if (comparison > 0) {
			System.out.println(ldt1 + " is larger than " + ldt2);
		} else if (comparison < 0) {
			System.out.println(ldt1 + " is smaller than " + ldt2);
		} else {
			System.out.println(ldt1 + " is equal to " + ldt2);
		}
	}
	public static void main(String[] args) {
		LocalDate anniversary = LocalDate.of(2000, Month.NOVEMBER, 11);
		LocalDate today = LocalDate.now();
		compareDates(anniversary, today);
	}
}

DB Connection Util

public class ConnectionUtil {
	public static Connection getConnection() throws Exception {
		Connection con = null;
		String url = "jdbc:mysql://localhost/SampleDB";
		String userName = "root";
		String passWord = "";
		try {
			Class.forName("com.mysql.jdbc.Driver");
			con = DriverManager.getConnection(url, userName, passWord);
		} catch (Exception e) {
			e.printStackTrace();
			throw new Exception(e);
		}
		return con;
	}
	public static void close(Connection conn , Statement stmt, ResultSet rs){
		try
		{
			if ( rs != null ){
				rs.close();
			}
			if ( stmt != null ) {
				stmt.close();
			}
			if ( conn != null ){
				conn.close();
			}
		}
		catch(SQLException e){
		}
	}
}