net.sf.jguiraffe.transform

Class DefaultValidationResult

java.lang.Object

net.sf.jguiraffe.transform.DefaultValidationResult

All Implemented Interfaces:

ValidationResult

public final class DefaultValidationResult
extends Object
implements ValidationResult

A default implementation of the ValidationResult interface.

Instances of this class store a collection of validation error messages. If no messages exist with a ValidationMessageLevel of ERROR, the validation result is considered to be valid. It may contain other messages which are only warning messages.

Clients do not create instances directly through the constructor, but use the nested Builder class. Once a builder is created, an arbitrary number of validation error messages can be added. If all messages have been added, the build() method creates an immutable instance of DefaultValidationResult. This has the advantage that all fields of DefaultValidationResult can be made final. Therefore objects of this class are thread-safe (note that is not true for the Builder objects).

There is also a constant representing a validation result for a successful validation. This field can be used in custom validator implementations rather than creating a new instance of this class.

Version:

$Id: DefaultValidationResult.java 205 2012-01-29 18:29:57Z oheger $

Author:

Oliver Heger

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DefaultValidationResult.Builder A builder class for creating instances of DefaultValidationResult.

Field Summary

Fields

Modifier and Type	Field and Description
static ValidationResult	VALID Constant for a validation result object for a successful validation.

Method Summary

Modifier and Type	Method and Description
static ValidationResult	createValidationErrorResult(TransformerContext context, String key, Object... params) Creates a ValidationResult object with the specified error message.
static ValidationMessage	createValidationMessage(TransformerContext context, String key, Object... params) Creates a ValidationMessage object for the specified error message.
boolean	equals(Object obj) Compares this object to another one.
Collection<ValidationMessage>	getValidationMessages() Returns an unmodifiable collection with error messages.
Collection<ValidationMessage>	getValidationMessages(ValidationMessageLevel level) Returns an unmodifiable collection with the ValidationMessage objects with the specified ValidationMessageLevel.
int	hashCode() Returns a hash code for this object.
boolean	hasMessages(ValidationMessageLevel level) Returns a flag whether messages of the specified level are available.
boolean	isValid() Returns a flag whether the validation was successful.
static ValidationResult	merge(ValidationResult vr1, ValidationResult vr2) Combines two validation result objects to a combined result.
String	toString() Returns a string representation for this object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

VALID

public static final ValidationResult VALID

Constant for a validation result object for a successful validation.

Method Detail

isValid

public boolean isValid()

Returns a flag whether the validation was successful. This implementation tests if error messages have been added to this object.

Specified by:

isValid in interface ValidationResult

Returns:

a flag if validation was successful

getValidationMessages

public Collection<ValidationMessage> getValidationMessages()

Returns an unmodifiable collection with error messages.

Specified by:

getValidationMessages in interface ValidationResult

Returns:

a collection with the error messages

getValidationMessages

public Collection<ValidationMessage> getValidationMessages(ValidationMessageLevel level)

Returns an unmodifiable collection with the ValidationMessage objects with the specified ValidationMessageLevel.

Specified by:

getValidationMessages in interface ValidationResult

Parameters:

level - the ValidationMessageLevel

Returns:

a collection with the requested messages

hasMessages

public boolean hasMessages(ValidationMessageLevel level)

Returns a flag whether messages of the specified level are available. These flags are initialized at construction time, so this method is pretty efficient.

Specified by:

hasMessages in interface ValidationResult

Parameters:

level - the ValidationMessageLevel in question

Returns:

a flag whether messages with this level are available

equals

public boolean equals(Object obj)

Compares this object to another one. Two validation result objects are considered equal if and only if they contain the same error messages.

Overrides:

equals in class Object

Parameters:

obj - the object to compare to

Returns:

a flag whether the objects are equal

hashCode

public int hashCode()

Returns a hash code for this object.

Overrides:

hashCode in class Object

Returns:

a hash code

toString

public String toString()

Returns a string representation for this object. This string will also contain the string representations for all contained error messages.

Overrides:

toString in class Object

Returns:

a string for this object

merge

public static ValidationResult merge(ValidationResult vr1,
                                     ValidationResult vr2)

Combines two validation result objects to a combined result. If one of the passed in result objects is invalid, the resulting object will also be invalid. It will contain the union of all error messages. A new ValidationResult object is created only if necessary: If one of the arguments is valid and has no warning messages, the other argument is returned. The same is true for null arguments. This method returns null only if both arguments are null.

Parameters:

vr1 - the first validation result object

vr2 - the second validation result object

Returns:

a combined validation result

createValidationMessage

public static ValidationMessage createValidationMessage(TransformerContext context,
                                                        String key,
                                                        Object... params)

Creates a ValidationMessage object for the specified error message. This is a convenience method that obtains the ValidationMessageHandler from the TransformerContext and obtains a ValidationMessage for the specified parameters.

Parameters:

context - the TransformerContext (must not be null)

key - the key of the error message

params - optional parameters for the error message

Returns:

a ValidationResult object with the specified message

Throws:

IllegalArgumentException - if the TransformerContext is null

createValidationErrorResult

public static ValidationResult createValidationErrorResult(TransformerContext context,
                                                           String key,
                                                           Object... params)

Creates a ValidationResult object with the specified error message. This is a convenience method for the frequent case that a ValidationResult object with exactly one error message has to be created. It obtains the ValidationMessageHandler from the TransformerContext, obtains a ValidationMessage for the specified parameters, and creates a ValidationResult object with exactly this message.

Parameters:

context - the TransformerContext (must not be null)

key - the key of the error message

params - optional parameters for the error message

Returns:

a ValidationResult object with this error message

Throws:

IllegalArgumentException - if the TransformerContext is null