Regular expression date pattern
(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\d\d) |
(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\d\d)
This regular expression refers to a pattern which validates the date in dd/mm/yyyy pattern.
Example
package com.w3spoint;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexTest {
private static final String PATTERN =
"(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\d\d)";
public static boolean validate(final String date){
Pattern pattern = Pattern.compile(PATTERN);
Matcher 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;
} else if (month.equals("2") || month.equals("02")) {
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[]){
List<String> values = new ArrayList<String>();
values.add("9/4/2018");
values.add("09/04/2018");
values.add("39/4/2018");
values.add("31/11/2010");
for (String value : values){
if(validate(value)){
System.out.println("Date "+ value +" is valid");
}else{
System.out.println("Date "+ value +" is invalid");
}
}
}
} |
package com.w3spoint; import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern; public class RegexTest {
private static final String PATTERN =
"(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/((19|20)\d\d)";
public static boolean validate(final String date){
Pattern pattern = Pattern.compile(PATTERN);
Matcher 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;
} else if (month.equals("2") || month.equals("02")) {
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[]){
List<String> values = new ArrayList<String>();
values.add("9/4/2018");
values.add("09/04/2018");
values.add("39/4/2018");
values.add("31/11/2010");
for (String value : values){
if(validate(value)){
System.out.println("Date "+ value +" is valid");
}else{
System.out.println("Date "+ value +" is invalid");
}
}
}
}
Output
Date 9/4/2018 is valid
Date 09/04/2018 is valid
Date 39/4/2018 is invalid
Date 31/11/2010 is invalid |
Date 9/4/2018 is valid
Date 09/04/2018 is valid
Date 39/4/2018 is invalid
Date 31/11/2010 is invalid