Package org.apache.commons.validator.routines

This package contains independant validation routines.

Class Summary

AbstractCalendarValidator Abstract class for Date/Time/Calendar validation.
AbstractFormatValidator Abstract class for Format based Validation.
AbstractNumberValidator Abstract class for Number Validation.
BigDecimalValidator BigDecimal Validation and Conversion routines (java.math.BigDecimal).
BigIntegerValidator BigInteger Validation and Conversion routines (java.math.BigInteger).
ByteValidator Byte Validation and Conversion routines (java.lang.Byte).
CalendarValidator Calendar Validation and Conversion routines (java.util.Calendar).
CurrencyValidator Currency Validation and Conversion routines (java.math.BigDecimal).
DateValidator Date Validation and Conversion routines (java.util.Date).
DoubleValidator Double Validation and Conversion routines (java.lang.Double).
FloatValidator Float Validation and Conversion routines (java.lang.Float).
IntegerValidator Integer Validation and Conversion routines (java.lang.Integer).
LongValidator Long Validation and Conversion routines (java.lang.Long).
PercentValidator Percentage Validation and Conversion routines (java.math.BigDecimal).
ShortValidator Short Validation and Conversion routines (java.lang.Short).
TimeValidator Time Validation and Conversion routines (java.util.Calendar).
This package contains independant validation routines.

Table of Contents

  • 2. Numeric Validators
  • 1. Overview

    Commons Validator serves two purposes:

    This package has been created, since version 1.3.0, in an attempt to clearly separate these two concerns and is the location for the standard, independant validation routines/functions in Commons Validator.

    The contents of this package have no dependencies on the framework aspect of Commons Validator and can be used on their own.

    2. Date and Time Validators

    2.1 Overview

    The date and time validators either validate according to a specified format or use a standard format for a specified Locale.

    2.2 Validating a Date Value

    You can either use one of the isValid() methods to just determine if a date is valid, or use one of the validate() methods to validate a date and convert it to a java.util.Date...

    // Get the Date validator
    DateValidator validator = DateValidator.getInstance();
    // Validate/Convert the date
    Date fooDate = validator.validate(fooString, "dd/MM/yyyy");
    if (fooDate == null) {
    // error...not a valid date
    return;
    }
    

    The following methods are provided to validate a date/time (return a boolean result):

    The following methods are provided to validate a date/time and convert it to either a java.util.Date or java.util.Calendar:

    2.3 Formatting

    Formatting and validating are two sides of the same coin. Typically input values which are converted from Strings according to a specified format also have to be rendered for output in the same format. These validators provide the mechanism for formatting from date/time objects to Strings. The following methods are provided to format date/time values as Strings:

    2.4 Time Zones

    If the date being parsed relates to a different time zone than the system default, you can specify the TimeZone to use when validating/converting:

    // Get the GMT time zone
    TimeZone GMT = TimeZone.getInstance("GMT");
    // Validate/Convert the date using GMT
    Date fooDate = validator.validate(fooString, "dd/MM/yyyy", GMT);
    

    The followng Time Zone flavours of the Validation/Conversion methods are provided:

    2.5 Comparing Dates and Times

    As well as validating that a value is a valid date or time, these validators also provide date comparison functions. The DateValidator and CalendarValidator provide functions for comparing years, quarters, months, weeks and dates and the TimeValidator provides functions for comparing hours, minutes, seconds and milliseconds. For example, to check that a date is in the current month, you could use the compareMonths() method, which compares the year and month components of a date:

    // Check if the date is in the current month 
    int compare = validator.compareMonths(fooDate, new Date(), null); 
    if (compare == 0) { 
    // do current month processing
    return;
    }
    // Check if the date is in the previous quarter
    compare = validator.compareQuarters(fooDate, new Date(), null);
    if (compare <320) {
    // do previous quarter processing
    return;
    }
    // Check if the date is in the next year
    compare = validator.compareYears(fooDate, new Date(), null);
    if (compare > 0) {
    // do next year processing
    return;
    }
    

    3 Numeric Validators

    3.1 Overview

    The numeric validators either validate according to a specified format or use a standard format for a specified Locale or use a custom format for a specified Locale.

    3.2 Validating a Numeric Value

    You can either use one of the isValid() methods to just determine if a number is valid, or use one of the validate() methods to validate a number and convert it to an appropriate type.

    The following example validates an integer against a custom pattern for the German locale. Please note the format is specified using the standard symbols for java.text.DecimalFormat so although the decimal separator is indicated as a period (".") in the format, the validator will check using the German decimal separator - which is a comma (",").

    // Get the Integer validator
    IntegerValidator validator = IntegerValidator.getInstance();
    // Validate/Convert the number
    Integer fooInteger = validator.validate(fooString, "#,##0.00", Locale.GERMAN);
    if (fooInteger == null) {
    // error...not a valid Integer
    return;
    }
    

    The following methods are provided to validate a number (return a boolean result):

    The following methods are provided to validate a number and convert it one of the java.lang.Number implementations:

    3.3 Formatting

    Formatting and validating are two sides of the same coin. Typically input values which are converted from Strings according to a specified format also have to be rendered for output in the same format. These validators provide the mechanism for formatting from numeric objects to Strings. The following methods are provided to format numeric values as Strings:

    3.4 Comparing Numbers

    As well as validating that a value is a valid number, these validators also provide functions for validating the minimum, maximum and range of a value.

    // Check the number is between 25 and 75
    if (validator.isInRange(fooInteger, 25, 75) {
    // valid...in the specified range
    return;
    }
    

    3.5 Currency Validation

    A default Currency Validator implementation is provided, although all the numeric validators support currency validation. The default implementation converts currency amounts to a java.math.BigDecimal and additionally it provides lenient currency symbol validation. That is, currency amounts are valid with or without the currency symbol.

    BigDecimalValidator validator = CurrencyValidator.getInstance();
    BigDecimal fooAmount = validator.validate("$12,500.00", Locale.US);
    if (fooAmount == null) {
    // error...not a valid currency amount
    return;
    }
    // Check the amount is a minimum of $1,000
    if (validator.minValue(fooAmount, 1000) {
    // valid...in the specified range
    return;
    }
    

    If, for example, you want to use the Integer Validator to validate a currency, then you can simply create a new instance with the appropriate format style. Note that the other validators do not support the lenient currency symbol validation.

    IntegerValidator validator = 
    new IntegerValidator(true, IntegerValidator.CURRENCY_FORMAT);
    String pattern = "#,###" + '\u00A4' + '\u00A4';  // Use international symbol
    Integer fooAmount = validator.validate("10.100EUR", pattern, Locale.GERMAN);
    if (fooAmount == null) {
    // error...not a valid currency amount
    return;
    }
    

    3.6 Percent Validation

    A default Percent Validator implementation is provided, although the Float, Double and BigDecimal validators also support percent validation. The default implementation converts percent amounts to a java.math.BigDecimal and additionally it provides lenient percent symbol validation. That is, percent amounts are valid with or without the percent symbol.

    BigDecimalValidator validator = PercentValidator.getInstance();
    BigDecimal fooPercent = validator.validate("20%", Locale.US);
    if (fooPercent == null) {
    // error...not a valid percent
    return;
    }
    // Check the percent is between 10% and 90%
    if (validator.isInRange(fooPercent, 0.1, 0.9) {
    // valid...in the specified range
    return;
    }
    

    If, for example, you want to use the Float Validator to validate a percent, then you can simply create a new instance with the appropriate format style. Note that the other validators do not support the lenient percent symbol validation.

    FloatValidator validator = 
    new FloatValidator(true, FloatValidator.PERCENT_FORMAT);
    Float fooPercent = validator.validate("20%", "###%");
    if (fooPercent == null) {
    // error...not a valid percent
    return;
    }
    

    Note: in theory the other numeric validators besides Float, Double and BigDecimal (i.e. Byte, Short, Integer, Long and BigInteger) also support percent validation. However, since they don't allow fractions they will only work with percentages greater than 100%.


    Copyright (c) 2001-2004 Apache Software Foundation