所有已知子接口:
SmartValidator
所有已知实现类:
CustomValidatorBean, LocalValidatorFactoryBean, OptionalValidatorFactoryBean, SpringValidatorAdapter
```
public interface Validator
```
A validator for application-specific objects.
This interface is totally divorced from any infrastructure or context; that is to say it is not coupled to validating only objects in the web tier, the data-access tier, or the whatever-tier. As such it is amenable to being used in any layer of an application, and supports the encapsulation of validation logic as a first-class citizen in its own right.
Find below a simple but complete Validator implementation, which validates that the various String properties of a UserLogin instance are not empty (that is they are not null and do not consist wholly of whitespace), and that any password that is present is at least 'MINIMUM_PASSWORD_LENGTH' characters in length.
```
 public class UserLoginValidator implements Validator {

    private static final int MINIMUM_PASSWORD_LENGTH = 6;

    public boolean supports(Class clazz) {
       return UserLogin.class.isAssignableFrom(clazz);
    }

    public void validate(Object target, Errors errors) {
       ValidationUtils.rejectIfEmptyOrWhitespace(errors, "userName", "field.required");
       ValidationUtils.rejectIfEmptyOrWhitespace(errors, "password", "field.required");
       UserLogin login = (UserLogin) target;
       if (login.getPassword() != null
             && login.getPassword().trim().length() < MINIMUM_PASSWORD_LENGTH) {
          errors.rejectValue("password", "field.min.length",
                new Object[]{Integer.valueOf(MINIMUM_PASSWORD_LENGTH)},
                "The password must be at least [" + MINIMUM_PASSWORD_LENGTH + "] characters in length.");
       }
    }
 }
```
See also the Spring reference manual for a fuller discussion of the Validator interface and its role in an enterprise application.
作者:
Rod Johnson
另请参阅:
Errors, ValidationUtils

方法概要

所有方法实例方法抽象方法
修饰符和类型	方法	说明
`boolean`	`supports(Class<?> clazz)`	Can this `Validatorvalidate` instances of the supplied `clazz`?
`void`	`validate(Object target, Errors errors)`	Validate the supplied `target` object, which must be of a `Class` for which the `supports(Class)` method typically has (or would) return `true`.

- 方法详细资料
  - supports
```
boolean supports(Class<?> clazz)
```
    Can this Validatorvalidate instances of the supplied clazz?
    This method is typically implemented like so:
    return Foo.class.isAssignableFrom(clazz);
    (Where Foo is the class (or superclass) of the actual object instance that is to be validated.)
    参数:
    clazz - the Class that this Validator is being asked if it can validate
    返回:
    true if this Validator can indeed validate instances of the supplied clazz
  - validate
```
void validate(Object target,
              Errors errors)
```
    Validate the supplied target object, which must be of a Class for which the supports(Class) method typically has (or would) return true.
    The supplied errors instance can be used to report any resulting validation errors.
    参数:
    target - the object that is to be validated (can be null)
    errors - contextual state about the validation process (never null)
    另请参阅:
    ValidationUtils

接口 Validator

方法概要

方法详细资料

supports

validate