LengthValidator (Java EE 5 SDK)

javax.faces.validator Class LengthValidator

java.lang.Object
  javax.faces.validator.LengthValidator

所有已实现的接口:

EventListener, StateHolder, Validator

public class LengthValidator

extends Object

implements Validator, StateHolder

LengthValidator is a Validator that checks the number of characters in the String representation of the value of the associated component. The following algorithm is implemented:

• Convert the passed value to a String, if necessary, by calling its toString() method.
• If a maximum property has been configured on this Validator, check the length of the converted String against this limit. If the String length is larger than the specified maximum, throw a ValidatorException containing a a MAXIMUM_MESSAGE_ID message.
• If a minimum property has been configured on this Validator, check the length of the converted String against this limit. If the String length is less than the specified minimum, throw a ValidatorException containing a a MINIMUM_MESSAGE_ID message.

For all of the above cases that cause a ValidatorException to be thrown, if there are parameters to the message that match up with validator parameters, the values of these parameters must be converted using the Converter registered in the application under the converter id javax.faces.Number. This allows the values to be localized according to the current Locale.

VALIDATOR_ID

public static final String VALIDATOR_ID

The standard validator id for this validator.

另请参见:

常量字段

MAXIMUM_MESSAGE_ID

public static final String MAXIMUM_MESSAGE_ID

The message identifier of the FacesMessage to be created if the maximum length check fails. The message format string for this message may optionally include the following placeholders:

• {0} replaced by the configured maximum length.
• {1} replaced by a String whose value is the label of the input component that produced this message.

另请参见:

常量字段

MINIMUM_MESSAGE_ID

public static final String MINIMUM_MESSAGE_ID

The message identifier of the FacesMessage to be created if the minimum length check fails. The message format string for this message may optionally include the following placeholders:

• {0} replaced by the configured minimum length.
• {1} replaced by a String whose value is the label of the input component that produced this message.

另请参见:

常量字段

LengthValidator

public LengthValidator()

Construct a Validator with no preconfigured limits.

LengthValidator

public LengthValidator(int maximum)

Construct a Validator with the specified preconfigured limit.

参数:

maximum - Maximum value to allow

LengthValidator

public LengthValidator(int maximum,
                       int minimum)

Construct a Validator with the specified preconfigured limits.

参数:

maximum - Maximum value to allow

minimum - Minimum value to allow

getMaximum

public int getMaximum()

Return the maximum length to be enforced by this Validator, or 0 if the maximum has not been set.

setMaximum

public void setMaximum(int maximum)

Set the maximum length to be enforced by this Validator.

参数:

maximum - The new maximum value

getMinimum

public int getMinimum()

Return the minimum length to be enforced by this Validator, or 0 if the minimum has not been set.

setMinimum

public void setMinimum(int minimum)

Set the minimum length to be enforced by this Validator.

参数:

minimum - The new minimum value

validate

public void validate(FacesContext context,
                     UIComponent component,
                     Object value)
              throws ValidatorException

Description copied from interface: Validator

Perform the correctness checks implemented by this Validator against the specified UIComponent. If any violations are found, a ValidatorException will be thrown containing the FacesMessage describing the failure.

规范说明:

validate in interface Validator

参数:

context - FacesContext for the request we are processing

component - UIComponent we are checking for correctness

value - the value to validate

抛出异常:

NullPointerException - if context or component is null

ValidatorException - if validation fails

equals

public boolean equals(Object otherObj)

重写:

equals in class Object

hashCode

public int hashCode()

重写:

hashCode in class Object

saveState

public Object saveState(FacesContext context)

Description copied from interface: StateHolder

Gets the state of the instance as a Serializable Object.

If the class that implements this interface has references to instances that implement StateHolder (such as a UIComponent with event handlers, validators, etc.) this method must call the StateHolder.saveState(javax.faces.context.FacesContext) method on all those instances as well. This method must not save the state of children and facets. That is done via the StateManager

This method must not alter the state of the implementing object. In other words, after executing this code:

 Object state = component.saveState(facesContext);
 

component should be the same as before executing it.

The return from this method must be Serializable

规范说明:

saveState in interface StateHolder

public void restoreState(FacesContext context,
                         Object state)

public boolean isTransient()

public void setTransient(boolean transientValue)