Java tutorial
/*
* Copyright WizTools.org
* Licensed under the Apache License, Version 2.0:
* http://www.apache.org/licenses/LICENSE-2.0
*/
//package org.wiztools.commons;
import java.text.Format;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.regex.Pattern;
/**
*
* @author subwiz
*/
public final class DateUtil {
private static final SimpleDateFormat SDF_ISO_DATE = new SimpleDateFormat(
"yyyy-MM-dd");
private static final SimpleDateFormat SDF_ISO_TIME = new SimpleDateFormat(
"HH:mm:ss");
/**
* Returns the date in ISO 8601 format yyyy-MM-dd.
* @param date
* @return
*/
public static String getAsISODateString(final Date date){
return SDF_ISO_DATE.format(date);
}
/**
* Returns the date and time in ISO 8601 format yyyy-MM-dd HH:mm:ss
* @param date
* @return
*/
public static String getAsISODateTimeString(final Date date){
return SDF_ISO_DATE.format(date) + "T" + SDF_ISO_TIME.format(date);
}
/**
* Returns java.util.Date object for the ISO 8601 formatted String yyyy-MM-dd.
* @param dateStr
* @return
*/
public static Date getFromISODateString(final String dateStr){
try{
Format fmt = new SimpleDateFormat("yyyy-MM-dd");
return (Date) fmt.parseObject(dateStr);
}
catch(ParseException ex) {
throw new IllegalArgumentException(ex);
}
}
/**
* This is an inclusive method: returns true if the date is equal to startDate or endDate.
* @param startDate The start date.
* @param endDate The end date.
* @param date The date to verify.
* @return true if the date falls between start date and end date.
*/
public static boolean isDateBetween(final Date startDate,
final Date endDate,
final Date date) {
// check if end date is later than start date:
if(startDate.compareTo(endDate) > 0) {
throw new IllegalArgumentException("Start date cannot be greater than end date!");
}
if(date.compareTo(startDate) >= 0 && date.compareTo(endDate) <= 0) {
return true;
}
return false;
}
private static Date getDatePlus(final int unit, final Date date, final int quantity) {
Calendar c = Calendar.getInstance();
c.clear();
c.setTime(date);
c.add(unit, quantity);
return c.getTime();
}
/**
* Adds the number of days to the date and returns the new Date instance.
* @param date Input date.
* @param months Number of days to add.
* @return Computed date.
*/
public static Date getDatePlusDays(final Date date, final int days){
return getDatePlus(Calendar.DATE, date, days);
}
/**
* Adds the number of months to the date and returns the new Date instance.
* @param date Input date.
* @param months Number of months to add.
* @return Computed date.
*/
public static Date getDatePlusMonths(final Date date, final int months){
return getDatePlus(Calendar.MONTH, date, months);
}
/**
* Adds the number of years to the date and returns the new Date instance.
* @param date Input date.
* @param years Number of years to add.
* @return Computed date.
*/
public static Date getDatePlusYears(final Date date, final int years){
return getDatePlus(Calendar.YEAR, date, years);
}
// Date Parsing using common pattern:
private static final Pattern p1 = Pattern.compile("[0-9]{1,2}-[0-9]{1,2}-[0-9]{2}");
private static final SimpleDateFormat sdf_p1 = new SimpleDateFormat("dd-MM-yy");
private static final Pattern p2 = Pattern.compile("[0-9]{1,2}-[0-9]{1,2}-[0-9]{4}");
private static final SimpleDateFormat sdf_p2 = new SimpleDateFormat("dd-MM-yyyy");
private static final Pattern p3 = Pattern.compile("[0-9]{1,2}/[0-9]{1,2}/[0-9]{2}");
private static final SimpleDateFormat sdf_p3 = new SimpleDateFormat("dd/MM/yy");
private static final Pattern p4 = Pattern.compile("[0-9]{1,2}/[0-9]{1,2}/[0-9]{4}");
private static final SimpleDateFormat sdf_p4 = new SimpleDateFormat("dd/MM/yyyy");
private static final Pattern p5 = Pattern.compile("[A-Za-z]{3} [0-9]{1,2}, [0-9]{4}");
private static final SimpleDateFormat sdf_p5 = new SimpleDateFormat("MMM dd, yyyy");
private static final Pattern p6 = Pattern.compile("[A-Za-z]{3} [0-9]{1,2} [0-9]{4}");
private static final SimpleDateFormat sdf_p6 = new SimpleDateFormat("MMM dd yyyy");
private static final Pattern p7 = Pattern.compile("[0-9]{4}-[0-9]{2}-[0-9]{2}");
private static final SimpleDateFormat sdf_p7 = new SimpleDateFormat("yyyy-MM-dd");
/**
* Tries to match common patterns by which date is mentioned, and returns a Date object.
* @param dateStr The date in common pattern.
* @return The java.util.Date object constructed by parsing the input string.
* @throws ParseException Thrown when not able to parse the date string.
*/
public static Date getDateFromString(final String dateStr) throws ParseException{
SimpleDateFormat sdf = null;
if(p1.matcher(dateStr).matches()){
sdf = sdf_p1;
}
else if(p2.matcher(dateStr).matches()){
sdf = sdf_p2;
}
else if(p3.matcher(dateStr).matches()){
sdf = sdf_p3;
}
else if(p4.matcher(dateStr).matches()){
sdf = sdf_p4;
}
else if(p5.matcher(dateStr).matches()){
sdf = sdf_p5;
}
else if(p6.matcher(dateStr).matches()){
sdf = sdf_p6;
}
else if(p7.matcher(dateStr).matches()){
sdf = sdf_p7;
}
if(sdf != null){
return sdf.parse(dateStr);
}
throw new ParseException(dateStr + " does not match any defined pattern!", 0);
}
public static Date now(){
return new Date();
}
}--------------
/*
* Copyright WizTools.org
* Licensed under the Apache License, Version 2.0:
* http://www.apache.org/licenses/LICENSE-2.0
*/
package org.wiztools.commons;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.junit.Assert.*;
/**
*
* @author subwiz
*/
public class DateUtilTest {
public DateUtilTest() {
}
@BeforeClass
public static void setUpClass() throws Exception {
}
@AfterClass
public static void tearDownClass() throws Exception {
}
@Before
public void setUp() {
}
@After
public void tearDown() {
}
@Test
public void testIsDateBetween() {
System.out.println("isDateBetween()");
Date now = DateUtil.now();
Date startDate = DateUtil.getDatePlusDays(now, -1);
Date endDate = DateUtil.getDatePlusDays(now, 1);
assertTrue(DateUtil.isDateBetween(startDate, endDate, now));
}
/**
* Test of getAsISODateString method, of class DateUtil.
*/
@Test
public void testGetAsISODateString() {
System.out.println("getAsISODateString");
Calendar c = Calendar.getInstance();
c.clear();
c.set(Calendar.YEAR, 1979);
c.set(Calendar.MONTH, 1); // 1 means Feb.
c.set(Calendar.DATE, 15);
Date date = c.getTime();
String expResult = "1979-02-15";
String result = DateUtil.getAsISODateString(date);
assertEquals(expResult, result);
}
/**
* Test of getAsISODateTimeString method, of class DateUtil.
*/
@Test
public void testGetAsISODateTimeString() {
System.out.println("getAsISODateTimeString");
Calendar c = Calendar.getInstance();
c.clear();
c.set(Calendar.YEAR, 1979);
c.set(Calendar.MONTH, 1); // 1 means Feb.
c.set(Calendar.DATE, 15);
c.set(Calendar.HOUR, 5);
c.set(Calendar.MINUTE, 5);
c.set(Calendar.SECOND, 5);
Date date = c.getTime();
String expResult = "1979-02-15T05:05:05";
String result = DateUtil.getAsISODateTimeString(date);
assertEquals(expResult, result);
}
/**
* Test of getFromISODateString method, of class DateUtil.
*/
@Test
public void testGetFromISODateString() {
System.out.println("getFromISODateString");
String dateStr = "1979-02-15";
Calendar c = Calendar.getInstance();
c.clear();
c.set(Calendar.YEAR, 1979);
c.set(Calendar.MONTH, 1); // 1 means Feb.
c.set(Calendar.DATE, 15);
Date expResult = c.getTime();
Date result = DateUtil.getFromISODateString(dateStr);
assertEquals(expResult, result);
}
@Test
public void testGetDatePlusDays() {
System.out.println("getDatePlusDays");
Calendar c = Calendar.getInstance();
c.clear();
c.set(Calendar.YEAR, 1979);
c.set(Calendar.MONTH, 1); // 1 means Feb.
c.set(Calendar.DATE, 15);
Date date = DateUtil.getDatePlusDays(c.getTime(), 5);
assertEquals(new SimpleDateFormat("dd-MM-yyyy").format(date), "20-02-1979");
}
@Test
public void testGetDateFromString() throws Exception {
Date d = DateUtil.getDateFromString("jan 1, 2010");
assertEquals(new SimpleDateFormat("dd-MM-yyyy").format(d), "01-01-2010");
d = DateUtil.getDateFromString("1-1-2010");
assertEquals(new SimpleDateFormat("dd-MM-yyyy").format(d), "01-01-2010");
d = DateUtil.getDateFromString("1/1/10");
assertEquals(new SimpleDateFormat("dd-MM-yyyy").format(d), "01-01-2010");
}
}