EN
Java - how to check if String is valid date?
16 points
In this post we can find code which can validate if String contains valid Date based on defined pattern.
xxxxxxxxxx1
import java.text.ParseException;2
import java.text.SimpleDateFormat;3
4
public class Example1 {5
6
public static void main(String[] args) {7
8
System.out.println(checkIfDateIsValid("2019-10-13")); // true9
System.out.println(checkIfDateIsValid("2019:10:13")); // false10
}11
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private static boolean checkIfDateIsValid(String date) {13
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");14
// With lenient parsing, the parser may use heuristics to interpret15
// inputs that do not precisely match this object's format.16
format.setLenient(false);17
try {18
format.parse(date);19
} catch (ParseException e) {20
return false;21
}22
return true;23
}24
}Output:
xxxxxxxxxx1
true2
falsexxxxxxxxxx1
import java.text.ParseException;2
import java.text.SimpleDateFormat;3
4
public class Example2 {5
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public static void main(String[] args) {7
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System.out.println("# Example 1");9
System.out.println(checkIfDateIsValid("yyyy-MM-dd", "2019-10-13")); // true10
System.out.println(checkIfDateIsValid("yyyy-MM-dd", "2019:10:13")); // false11
12
System.out.println("# Example 2");13
System.out.println(checkIfDateIsValid("yyyy/MM/dd", "2019/10/13")); // true14
15
System.out.println("# Example 3");16
System.out.println(checkIfDateIsValid("yyyy:MM:dd", "2019:10:13")); // true17
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System.out.println("# Example 4");19
System.out.println(checkIfDateIsValid("MM/dd/yyyy", "10/13/2019")); // true20
}21
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private static boolean checkIfDateIsValid(String pattern, String date) {23
SimpleDateFormat format = new SimpleDateFormat(pattern);24
// With lenient parsing, the parser may use heuristics to interpret25
// inputs that do not precisely match this object's format.26
format.setLenient(false);27
try {28
format.parse(date);29
} catch (ParseException e) {30
return false;31
}32
return true;33
}34
}Output:
xxxxxxxxxx1
# Example 12
true3
false4
# Example 25
true6
# Example 37
true8
# Example 49
truexxxxxxxxxx1
import java.time.LocalDate;2
import java.time.format.DateTimeFormatter;3
import java.time.format.DateTimeParseException;4
5
public class Example3 {6
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public static void main(String[] args) {8
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System.out.println(checkIfDateIsValid("2019-10-13")); // true10
System.out.println(checkIfDateIsValid("2019:10:13")); // false11
}12
13
private static boolean checkIfDateIsValid(String date) {14
try {15
LocalDate.parse(date, DateTimeFormatter.ISO_DATE);16
} catch (DateTimeParseException e) {17
return false;18
}19
return true;20
}21
}Output:
xxxxxxxxxx1
true2
falsexxxxxxxxxx1
import java.time.LocalDate;2
import java.time.format.DateTimeFormatter;3
import java.time.format.DateTimeParseException;4
5
public class Example4 {6
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public static void main(String[] args) {8
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System.out.println("# Example 1");10
System.out.println(checkIfDateIsValid(11
DateTimeFormatter.ISO_DATE, "2019-10-13")); // true12
13
System.out.println(checkIfDateIsValid(14
DateTimeFormatter.ISO_DATE, "2019:10:13")); // false15
16
System.out.println("# Example 2");17
System.out.println(checkIfDateIsValid(18
DateTimeFormatter.BASIC_ISO_DATE, "20191013")); // true19
20
System.out.println("# Example 3");21
System.out.println(checkIfDateIsValid(22
DateTimeFormatter.ISO_LOCAL_DATE, "2019-10-13")); // true23
}24
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private static boolean checkIfDateIsValid(DateTimeFormatter formatter, String date) {26
try {27
LocalDate.parse(date, formatter);28
} catch (DateTimeParseException e) {29
return false;30
}31
return true;32
}33
}Output:
xxxxxxxxxx1
# Example 12
true3
false4
# Example 25
true6
# Example 37
truexxxxxxxxxx1
import java.time.LocalDate;2
import java.time.format.DateTimeFormatter;3
import java.time.format.DateTimeParseException;4
5
public class Example5 {6
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public static void main(String[] args) {8
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System.out.println("# Example 1");10
System.out.println(checkIfDateIsValid("yyyy-MM-dd", "2019-10-13")); // true11
System.out.println(checkIfDateIsValid("yyyy-MM-dd", "2019:10:13")); // false12
13
System.out.println("# Example 2");14
System.out.println(checkIfDateIsValid("yyyy/MM/dd", "2019/10/13")); // true15
16
System.out.println("# Example 3");17
System.out.println(checkIfDateIsValid("yyyy:MM:dd", "2019:10:13")); // true18
19
System.out.println("# Example 4");20
System.out.println(checkIfDateIsValid("MM/dd/yyyy", "10/13/2019")); // true21
}22
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private static boolean checkIfDateIsValid(String pattern, String date) {24
try {25
DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);26
LocalDate.parse(date, formatter);27
} catch (DateTimeParseException e) {28
return false;29
}30
return true;31
}32
}Output:
xxxxxxxxxx1
# Example 12
true3
false4
# Example 25
true6
# Example 37
true8
# Example 49
true