Built in validators

Function name	**Requirement to processed value parameter**
areIn(List values, List list)	is a list which values are equal to any member of the specified list
areIn(List values, Set set)	is a list which values are equal to any member of the specified set
contains(String value, CharSequence substring)	contains the specified the specified sequence of char values
endsWith(String value, String suffix)	ends with the specified suffix
hasNotCRLF(String value)	does not contain a carriage return or a line feed character (see CRLF attack [26])
isAfter(Date value, Date minDate)	is a date after the specified one
isAfterNow(Date value)	is a date after now
isAlnum(String value)	is a string that matches /[a-zA-Z0-9]+/
isAlnumSpace(String value)	is a string that matches /[a-zA-Z0-9\s]+/
isAlpha(String value)	is a string that matches /[a-zA-Z]+/
isAlphaSpace(String value)	is a string that matches /[a-zA-Z\s]+/
isAny(List values)	is a list whose at least one member is true according to the Groovy Truth
isAny(List values, Closure closure)	is a list whose at least one member is valid according to a predicate
isBefore(Date value, Date maxDate)	is a date before the specified one
isBeforeNow(Date value)	is a date before now
isBetween(Number value, Number min, Number max)	falls within the specified range of decimal values
isBetween(Integer value, IntRange min..max)	falls within the specified integer range (uses HTML5 min and max attributes for the client side [18])
isBirthDateAlive(Date value)	is a date before the current year (or the current year) but not more than 120 years in the past
isBirthYearAlive	is a year before the current year (or the current year) but not more than 120 years in the past
isColor(String value)	is a CSS color
isCountryCode(String value)	is a country code [39]
isCurrencyCode(String value)	is a currency code (ISO 4217)
isEmail(String value)	is an email address compliant to RFC [21] (uses the HTML5 email input type for the client side)
isEmpty(List values)	is an empty list
isEmpty(String value)	is a string that matches /\s*/
isEqual(value, object) (alias eq)	is equal to the specified object
isEven(Long value)	is an even number
isEvery(List values)	is a list whose members are true according to the Groovy Truth
isEvery(List values, Closure closure)	is a list whose members are valid according to a predicate
isFalse(value)	coerces to boolean false
isFileExtensionIn(FileItem value, List<String> extenstions)	has an extension from the specified list (by default no extensions are allowed)
isFileSizeLess(FileItem value, Integer size)	is a file whose size is less than specified (in bytes)
isGreater(Number value, Number number) (alias ‒ gt)	is a number greater than the specified number
isGreaterEq(Number value, Number number)  (alias ‒ gte)	is a number greater or equal to the specified number
isHostname(String value)	is a host name: DNS host name (e.g. bit.ly), IP address, or local host name (e.g. localhost)
isIn(value, List list)	is equal to any member of the specified list
isIn(value, Set set)	is equal to any member of the specified set
isInternalUrl(String value)	is a URL that belongs to the same domain as the current request (can be useful for redirect URL)
isISBN(String value)	is ISBN [64]
isIPv4(String value)	is an IP address version 4
isIPv6(String value)	is an IP address version 6
isLengthEq(String value, Integer length)	has the specified string length
isLengthBetween(String value, Integer min, Integer max)	is within the specified range of string lengths (the range is inclusive)
isLengthLess(String value, Integer length)	has a string length less than specified value
isLengthLessEq(String value, Integer length)	has a string length less or equal to specified value
isLengthMore(String value, Integer length)	has a string length more than specified value
isLengthMoreEq(String value, Integer length)	has a string length more than or equal to the specified value
isLess(Number value, Number number) (alias: lt)	is a number less than the specified number
isLessEq(Number value, Number number) (alias: lte)	is a number less than or equal to the specified number
isMonth(Integer value)	is an integer between 1 and 12
isMonth(String value)	represents a month for the current locale or is an integer between 1 and 12
isName(String value)	contains only characters that occur in human names, i.e. [77]: [a-Z]|[\u00A0- \uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]
isNotSqlInjection(String value)	tests to see if the value appears to be an explicit SQL Injection attack (uses OWASP AppSensor [34])
isOdd(Long value)	is an odd number
isPhone(String value)	is an international phone number [77] (validator follows the forgiving format, thus parentheses, dots, spaces and hyphens are allowed)
isPostcode(String value, String countryCode) (alias isZipcode)	is a postcode valid for the specified country code (US and CA are supported [39])
isSSN(String value, String countryCode)	is social security number valid for specified country code [39]
isState(String value)	is a US or Canadian state or province in two letter format
isStrongPassword(String value, List<String> mediumPasswordRegexes, List<String> strongPasswordRegexes)	is compliant with a strong password policy A password is: - weak if it does not match some of mediumPasswordRegexes - medium if it does not match some of strongPasswordRegexes - strong if it matches all the given regexes Password is invalid if it is not strong, in this case ValidationException’s parameters field contains password strength (WEAK or MEDIUM), which then can be read on the client side
isTimeZone(String value)	is a ISO 8601 time zone [36]
isTrue(value)	coerces to boolean true
isUrl(String value)	is a well-formed URL [58]
isWeekDay(String value)	represents a day of the week for the current locale
matches(String value, String regexp)	is a string that matches the specified regex (uses HTML5 attribute pattern for the client side [25])
startsWith(String value, String prefix)	starts with the specified prefix