Date Format (dd/mm/yyyy) Regular Expression Pattern
(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\\d\\d)
Description
(#start of group #1
0?[1-9]#01-09or1-9
|#..or
[12][0-9]#10-19or20-29
|#..or
3[01]#30,31
)#end of group #1
/# follow by a"/"
(# start of group #2
0?[1-9]#01-09or1-9
|#..or
1[012]#10,11,12
)# end of group #2
/# follow by a"/"
(# start of group #3
(19|20)\\d\\d #19[0-9][0-9]or20[0-9][0-9]
) # end of group #3
Code:
package com.codewr.javacore.regular.expression;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
*
* @author codewr
*/
public class DateValidator {
private Pattern pattern;
private Matcher matcher;
private static final String DATE_PATTERN
= "(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\\d\\d)";
public DateValidator() {
pattern = Pattern.compile(DATE_PATTERN);
}
/**
* Validate date format with regular expression
*
* @param date date address for validation
* @return true valid date fromat, false invalid date format
*/
public boolean validate(final String date) {
matcher = pattern.matcher(date);
if (matcher.matches()) {
matcher.reset();
if (matcher.find()) {
String day = matcher.group(1);
String month = matcher.group(2);
int year = Integer.parseInt(matcher.group(3));
if (day.equals("31")
&& (month.equals("4") || month.equals("6") || month.equals("9")
|| month.equals("11") || month.equals("04") || month.equals("06")
|| month.equals("09"))) {
return false; // only 1,3,5,7,8,10,12 has 31 days
} else if (month.equals("2") || month.equals("02")) {
//leap year
if (year % 4 == 0) {
if (day.equals("30") || day.equals("31")) {
return false;
} else {
return true;
}
} else if (day.equals("29") || day.equals("30") || day.equals("31")) {
return false;
} else {
return true;
}
} else {
return true;
}
} else {
return false;
}
} else {
return false;
}
}
public static void main(String[] args) {
DateValidator dateValidator = new DateValidator();
boolean isValid = dateValidator.validate("20/2/2017");
System.out.println("date valid is "+isValid);
}
}
Code UnitTest:
Date valid:
1. “1/1/2010” , “01/01/2020”
2. “31/1/2010”, “31/01/2020”
3. “29/2/2008”, “29/02/2008”
4. “28/2/2009”, “28/02/2009”
5. “31/3/2010”, “31/03/2010”
6. “30/4/2010”, “30/04/2010”
7. “31/5/2010”, “31/05/2010”
8. “30/6/2010”, “30/06/2010”
9. “31/7/2010”, “31/07/2010”
10. “31/8/2010”, “31/08/2010”
11. “30/9/2010”, “30/09/2010”
12. “31/10/2010”, “31/10/2010”
13. “30/11/2010”, “30/11/2010”
14. “31/12/2010”, “31/12/2010”
Date invalid
1. “32/1/2010” , “32/01/2020” – day is out of range [1-31]
2. “1/13/2010”, “01/01/1820” – month is out of range [1-12], year is out of range [1900-2999]
3. “29/2/2007”, “29/02/2007” – 2007 is not leap year, only has 28 days
4. “30/2/2008”, “31/02/2008” – leap year in February has 29 days only
5. “29/a/2008”, “a/02/2008” – month is invalid, day is invalid
6. “333/2/2008”, “29/02/200a” – day is invalid, year is invalid
7. “31/4/20100”, “31/04/2010” – April has 30 days only
8. “31/6/2010”, “31/06/2010” -June has 30 days only
9. “31/9/2010”, “31/09/2010” – September has 30 days only
10. “31/11/2010” – November has 30 days only
import com.codewr.javacore.regular.expression.DateValidator;
import org.testng.Assert;
import org.testng.annotations.*;
/**
* Date format dd/mm/yyyy validator Testing
*
* @author codewr
*
*/
public class DateValidatorTest {
private DateValidator dateValidator;
@BeforeClass
public void initData() {
dateValidator = new DateValidator();
}
@DataProvider
public Object[][] ValidDateProvider() {
return new Object[][]{
new Object[]{"1/1/2010"}, new Object[]{"01/01/2020"},
new Object[]{"31/1/2010"}, new Object[]{"31/01/2020"},
new Object[]{"29/2/2008"}, new Object[]{"29/02/2008"},
new Object[]{"28/2/2009"}, new Object[]{"28/02/2009"},
new Object[]{"31/3/2010"}, new Object[]{"31/03/2010"},
new Object[]{"30/4/2010"}, new Object[]{"30/04/2010"},
new Object[]{"31/5/2010"}, new Object[]{"31/05/2010"},
new Object[]{"30/6/2010"}, new Object[]{"30/06/2010"},
new Object[]{"31/7/2010"}, new Object[]{"31/07/2010"},
new Object[]{"31/8/2010"}, new Object[]{"31/08/2010"},
new Object[]{"30/9/2010"}, new Object[]{"30/09/2010"},
new Object[]{"31/10/2010"}, new Object[]{"31/10/2010"},
new Object[]{"30/11/2010"}, new Object[]{"30/11/2010"},
new Object[]{"31/12/2010"}, new Object[]{"31/12/2010"}
};
}
@DataProvider
public Object[][] InvalidDateProvider() {
return new Object[][]{
new Object[]{"32/1/2010"}, new Object[]{"32/01/2020"},
new Object[]{"1/13/2010"}, new Object[]{"01/01/1820"},
new Object[]{"29/2/2007"}, new Object[]{"29/02/2007"},
new Object[]{"30/2/2008"}, new Object[]{"31/02/2008"},
new Object[]{"29/a/2008"}, new Object[]{"a/02/2008"},
new Object[]{"333/2/2008"}, new Object[]{"29/02/200a"},
new Object[]{"31/4/2010"}, new Object[]{"31/04/2010"},
new Object[]{"31/6/2010"}, new Object[]{"31/06/2010"},
new Object[]{"31/9/2010"}, new Object[]{"31/09/2010"},
new Object[]{"31/11/2010"}
};
}
@Test(dataProvider = "ValidDateProvider")
public void ValidDateTest(String date) {
boolean valid = dateValidator.validate(date);
System.out.println("Date is valid : " + date + " , " + valid);
Assert.assertEquals(true, valid);
}
@Test(dataProvider = "InvalidDateProvider",
dependsOnMethods = "ValidDateTest")
public void InValidDateTest(String date) {
boolean valid = dateValidator.validate(date);
System.out.println("Date is valid : " + date + " , " + valid);
Assert.assertEquals(false, valid);
}
}
Output:
Running DateValidatorTest
Date is valid : 1/1/2010 , true
Date is valid : 01/01/2020 , true
Date is valid : 31/1/2010 , true
Date is valid : 31/01/2020 , true
Date is valid : 29/2/2008 , true
Date is valid : 29/02/2008 , true
Date is valid : 28/2/2009 , true
Date is valid : 28/02/2009 , true
Date is valid : 31/3/2010 , true
Date is valid : 31/03/2010 , true
Date is valid : 30/4/2010 , true
Date is valid : 30/04/2010 , true
Date is valid : 31/5/2010 , true
Date is valid : 31/05/2010 , true
Date is valid : 30/6/2010 , true
Date is valid : 30/06/2010 , true
Date is valid : 31/7/2010 , true
Date is valid : 31/07/2010 , true
Date is valid : 31/8/2010 , true
Date is valid : 31/08/2010 , true
Date is valid : 30/9/2010 , true
Date is valid : 30/09/2010 , true
Date is valid : 31/10/2010 , true
Date is valid : 31/10/2010 , true
Date is valid : 30/11/2010 , true
Date is valid : 30/11/2010 , true
Date is valid : 31/12/2010 , true
Date is valid : 31/12/2010 , true
Date is valid : 32/1/2010 , false
Date is valid : 32/01/2020 , false
Date is valid : 1/13/2010 , false
Date is valid : 01/01/1820 , false
Date is valid : 29/2/2007 , false
Date is valid : 29/02/2007 , false
Date is valid : 30/2/2008 , false
Date is valid : 31/02/2008 , false
Date is valid : 29/a/2008 , false
Date is valid : a/02/2008 , false
Date is valid : 333/2/2008 , false
Date is valid : 29/02/200a , false
Date is valid : 31/4/2010 , false
Date is valid : 31/04/2010 , false
Date is valid : 31/6/2010 , false
Date is valid : 31/06/2010 , false
Date is valid : 31/9/2010 , false
Date is valid : 31/09/2010 , false
Date is valid : 31/11/2010 , false
Tests run: 47, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.878 sec
Results :
Tests run: 47, Failures: 0, Errors: 0, Skipped: 0
Note: file pom.xml add maven
<dependency>
<groupId>org.testng</groupId>
<artifactId>testng</artifactId>
<version>6.8</version>
<scope>test</scope>
</dependency>