## org.springframework.validation
Class ValidationUtils

    java.lang.Object
      org.springframework.validation.ValidationUtils

    public abstract class ValidationUtils

extends Object

Utility class offering convenient methods for invoking a `Validator` and for rejecting empty fields.

Checks for an empty field in `Validator` implementations can become one-liners when using `rejectIfEmpty(org.springframework.validation.Errors, java.lang.String, java.lang.String)` or `rejectIfEmptyOrWhitespace(org.springframework.validation.Errors, java.lang.String, java.lang.String)`.

Since:
  06.05.2003
Author:
  Juergen Hoeller, Dmitriy Kopylenko
See Also:
  `Validator`, `Errors`

Constructor Summary
`ValidationUtils()`

Method Summary
`static void` `invokeValidator(Validator validator, Object obj, Errors errors)` Invoke the given `Validator` for the supplied object and `Errors` instance.
`static void` `rejectIfEmpty(Errors errors, String field, String errorCode)` Reject the given field with the given error code if the value is empty.
`static void` `rejectIfEmpty(Errors errors, String field, String errorCode, Object[] errorArgs)` Reject the given field with the given error codea nd error arguments if the value is empty.
`static void` `rejectIfEmpty(Errors errors, String field, String errorCode, Object[] errorArgs, String defaultMessage)` Reject the given field with the given error code, error arguments and default message if the value is empty.
`static void` `rejectIfEmpty(Errors errors, String field, String errorCode, String defaultMessage)` Reject the given field with the given error code and default message if the value is empty.
`static void` `rejectIfEmptyOrWhitespace(Errors errors, String field, String errorCode)` Reject the given field with the given error code if the value is empty or just contains whitespace.
`static void` `rejectIfEmptyOrWhitespace(Errors errors, String field, String errorCode, Object[] errorArgs)` Reject the given field with the given error code and error arguments if the value is empty or just contains whitespace.
`static void` `rejectIfEmptyOrWhitespace(Errors errors, String field, String errorCode, Object[] errorArgs, String defaultMessage)` Reject the given field with the given error code, error arguments and default message if the value is empty or just contains whitespace.
`static void` `rejectIfEmptyOrWhitespace(Errors errors, String field, String errorCode, String defaultMessage)` Reject the given field with the given error code and default message if the value is empty or just contains whitespace.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### ValidationUtils

    public ValidationUtils()

Method Detail

### invokeValidator

    public static void invokeValidator(Validator validator,
                                       Object obj,
                                       Errors errors)

  Invoke the given `Validator` for the supplied object and `Errors` instance.

  Parameters:
    `validator` - the `Validator` to be invoked (must not be `null`)
    `obj` - the object to bind the parameters to
    `errors` - the `Errors` instance that should store the errors (must not be `null`)
  Throws:
    `IllegalArgumentException` - if either of the `Validator` or `Errors` arguments is `null`; or if the supplied `Validator` does not `support` the validation of the supplied object's type

### rejectIfEmpty

    public static void rejectIfEmpty(Errors errors,
                                     String field,
                                     String errorCode)

  Reject the given field with the given error code if the value is empty.

  An 'empty' value in this context means either `null` or the empty string "".

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - the error code, interpretable as message key

### rejectIfEmpty

    public static void rejectIfEmpty(Errors errors,
                                     String field,
                                     String errorCode,
                                     String defaultMessage)

  Reject the given field with the given error code and default message if the value is empty.

  An 'empty' value in this context means either `null` or the empty string "".

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - error code, interpretable as message key
    `defaultMessage` - fallback default message

### rejectIfEmpty

    public static void rejectIfEmpty(Errors errors,
                                     String field,
                                     String errorCode,
                                     Object[] errorArgs)

  Reject the given field with the given error codea nd error arguments if the value is empty.

  An 'empty' value in this context means either `null` or the empty string "".

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - the error code, interpretable as message key
    `errorArgs` - the error arguments, for argument binding via MessageFormat (can be `null`)

### rejectIfEmpty

    public static void rejectIfEmpty(Errors errors,
                                     String field,
                                     String errorCode,
                                     Object[] errorArgs,
                                     String defaultMessage)

  Reject the given field with the given error code, error arguments and default message if the value is empty.

  An 'empty' value in this context means either `null` or the empty string "".

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - the error code, interpretable as message key
    `errorArgs` - the error arguments, for argument binding via MessageFormat (can be `null`)
    `defaultMessage` - fallback default message

### rejectIfEmptyOrWhitespace

    public static void rejectIfEmptyOrWhitespace(Errors errors,
                                                 String field,
                                                 String errorCode)

  Reject the given field with the given error code if the value is empty or just contains whitespace.

  An 'empty' value in this context means either `null`, the empty string "", or consisting wholly of whitespace.

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - the error code, interpretable as message key

### rejectIfEmptyOrWhitespace

    public static void rejectIfEmptyOrWhitespace(Errors errors,
                                                 String field,
                                                 String errorCode,
                                                 String defaultMessage)

  Reject the given field with the given error code and default message if the value is empty or just contains whitespace.

  An 'empty' value in this context means either `null`, the empty string "", or consisting wholly of whitespace.

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - the error code, interpretable as message key
    `defaultMessage` - fallback default message

### rejectIfEmptyOrWhitespace

    public static void rejectIfEmptyOrWhitespace(Errors errors,
                                                 String field,
                                                 String errorCode,
                                                 Object[] errorArgs)

  Reject the given field with the given error code and error arguments if the value is empty or just contains whitespace.

  An 'empty' value in this context means either `null`, the empty string "", or consisting wholly of whitespace.

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - the error code, interpretable as message key
    `errorArgs` - the error arguments, for argument binding via MessageFormat (can be `null`)

### rejectIfEmptyOrWhitespace

    public static void rejectIfEmptyOrWhitespace(Errors errors,
                                                 String field,
                                                 String errorCode,
                                                 Object[] errorArgs,
                                                 String defaultMessage)

  Reject the given field with the given error code, error arguments and default message if the value is empty or just contains whitespace.

  An 'empty' value in this context means either `null`, the empty string "", or consisting wholly of whitespace.

  The object whose field is being validated does not need to be passed in because the `Errors` instance can resolve field values by itself (it will usually hold an internal reference to the target object).

  Parameters:
    `errors` - the `Errors` instance to register errors on
    `field` - the field name to check
    `errorCode` - the error code, interpretable as message key
    `errorArgs` - the error arguments, for argument binding via MessageFormat (can be `null`)
    `defaultMessage` - fallback default message