<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">OK <div><br></div><div>Here is the proposal I integrated in the spec. Main changes are in the email, the whole spec is here for reference.</div><div><br></div><div>Review very much welcome.</div><div><br></div><div><br></div><div><span class="Apple-style-span" style="font-family: -webkit-sans-serif; font-size: 14px; "><div class="titlepage" style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "><h2 class="title" style="clear: both; font-family: sans-serif; color: rgb(0, 51, 153); font-size: 140%; margin-top: 10px; padding-top: 5px; font-weight: bold; ">2.1. Constraint annotation</h2></div></div><div style="font-family: sans-serif; font-size: 14px; "></div></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">A constraint on a JavaBean is expressed through one or more annotations. An annotation is considered a constraint definition if its retention policy contains <tt class="literal" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">RUNTIME</tt> and if the annotation itself is annotated with <tt class="literal" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">javax.validation.Constraint</tt>.</p><pre class="programlisting" style="font-size: 100%; padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-top-color: rgb(204, 204, 204); border-right-color: rgb(204, 204, 204); border-bottom-color: rgb(204, 204, 204); border-left-color: rgb(204, 204, 204); background-color: rgb(244, 244, 244); font-family: monospace; width: auto; ">/**
* Link between a constraint annotation and its constraint validation implementations.
* <p/>
* A given constraint annotation should be annotated by a @Constraint
* annotation which refers to its list of constraint validation implementation.
*
* @author Emmanuel Bernard (emmanuel at hibernate.org)
* @author Gavin King
* @author Hardy Ferentschik
*/
@Documented
@Target({ ANNOTATION_TYPE })
@Retention(RUNTIME)
public @interface Constraint {
/**
* ConstraintValidator classes must reference distinct target types.
* If two validators refer to the same type, an exception will occur
*
* @return aray of ConstraintValidator classes implementing the constraint
*/
public Class<? extends ConstraintValidator<?,?>>[] validatedBy();
}</pre><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Constraint annotations can target any of the following <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ElementType</tt>s:</p><div class="itemizedlist" style="font-family: sans-serif; font-size: 14px; "><ul type="disc" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><tt class="literal" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">FIELD</tt> for constrained attributes</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><tt class="literal" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">METHOD</tt> for constrained getters</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><tt class="literal" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">TYPE</tt> for constrained beans</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><tt class="literal" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ANNOTATION_TYPE</tt> for constraints composing other constraints</p></li></ul></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">While other <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ElementType</tt>s are not forbidden, the provider does not have to recognize and process constraints placed on such types.</p><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Since a given constraint definition applies to one or more specific Java types, the JavaDoc for the constraint annotation should clearly state which types are supported. Applying a constraint annotation to an incompatible type will raise a <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">UnexpectedTypeForConstraintException</tt>. Care should be taken on defining the list of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt>. The type resolution algorithm (see <a href="file:///Users/manu/projects/specs/303/specbook/build/en/html_single/index.html#typevalidatorresolution" title="3.5.3. ConstraintValidator resolution algorithm" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); ">Section 3.5.3, “ConstraintValidator resolution algorithm”</a>) could lead to exceptions due to ambiguity.</p><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><br></p><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">[...]</p><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><br></p><div style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><br class="webkit-block-placeholder"></div><div class="titlepage" style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "><h2 class="title" style="clear: both; font-family: sans-serif; color: rgb(0, 51, 153); font-size: 140%; margin-top: 10px; padding-top: 5px; font-weight: bold; ">2.4. Constraint validation implementation</h2></div></div><div style="font-family: sans-serif; font-size: 14px; "></div></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">A constraint validation implementation performs the validation of a given constraint annotation for a given type. The implementation classes are specified by the <tt class="literal" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">validatedBy</tt> element of the<tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Contraint</tt> annotation that decorates the constraint definition. The constraint validation implementation implements the <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> interface.</p><div class="example" style="font-family: sans-serif; font-size: 14px; "><a name="d0e560" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); "></a><p class="title" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); margin-top: 10px; padding-top: 5px; font-weight: bold; "><b style="font-family: sans-serif; font-size: 14px; ">Example 2.10. ConstraintValidator interface</b></p><pre class="programlisting" style="font-size: 100%; padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-top-color: rgb(204, 204, 204); border-right-color: rgb(204, 204, 204); border-bottom-color: rgb(204, 204, 204); border-left-color: rgb(204, 204, 204); background-color: rgb(244, 244, 244); font-family: monospace; width: auto; ">/**
* Defines the logic to validate a given constraint A
* for a given object type T.
* Implementations must comply to the following restriction:
* T must resolve to a non parameterized type
*
* @author Emmanuel Bernard
* @author Hardy Ferentschik
*/
public interface ConstraintValidator<A extends Annotation, T> {
/**
* Validator parameters for a given constraint definition
* Annotations parameters are passed as key/value into parameters
* <p/>
* This method is guaranteed to be called before any of the other Constraint
* implementation methods
*
* @param constraintAnnotation parameters for a given constraint definition
*/
void initialize(A constraintAnnotation);
/**
* Implement the validation constraint.
* <code>object</code> state must not be changed by a Constraint implementation
*
* @param object object to validate
* @param constraintValidatorContext context in which the constraint is evaluated
*
* @return false if <code>object</code> does not pass the constraint
*/
boolean isValid(T object, ConstraintValidatorContext constraintValidatorContext);
}</pre></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Some restrictions apply on the generic type <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> (used in the <tt class="methodname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">isValid</tt> method). T must resolve in a non parameterized type:</p><div class="itemizedlist" style="font-family: sans-serif; font-size: 14px; "><ul type="disc" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">the type is not using generics</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">because the raw type is used instead of the generic version</p></li></ul></div><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in; font-family: sans-serif; font-size: 14px; padding-bottom: 5px; padding-left: 5px; padding-right: 5px; background-color: rgb(251, 218, 218); "><h3 class="title" style="font-family: sans-serif; color: rgb(0, 51, 153); font-size: 120%; margin-top: 10px; padding-top: 5px; font-weight: bold; ">Warning</h3><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Should we support unbounded wildcards?</p></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Here are some examples of valid definitions in <a href="file:///Users/manu/projects/specs/303/specbook/build/en/html_single/index.html#example-constraintsdefinitionimplementation-validationimplementation-validdef" title="Example 2.11. Valid ConstraintValidator definitions" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); ">Example 2.11, “Valid ConstraintValidator definitions”</a>.</p><div class="example" style="font-family: sans-serif; font-size: 14px; "><a name="example-constraintsdefinitionimplementation-validationimplementation-validdef" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); "></a><p class="title" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); margin-top: 10px; padding-top: 5px; font-weight: bold; "><b style="font-family: sans-serif; font-size: 14px; ">Example 2.11. Valid ConstraintValidator definitions</b></p><pre class="programlisting" style="font-size: 100%; padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-top-color: rgb(204, 204, 204); border-right-color: rgb(204, 204, 204); border-bottom-color: rgb(204, 204, 204); border-left-color: rgb(204, 204, 204); background-color: rgb(244, 244, 244); font-family: monospace; width: auto; ">//String is not making use of generics
public class SizeValidatorForString implements<Size, String> {...}
//Collection uses generics but the raw type is used
public class SizeValidatorForCollection implements<Size, Collection> {...}</pre></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">And some invalid definitions in <a href="file:///Users/manu/projects/specs/303/specbook/build/en/html_single/index.html#example-constraintsdefinitionimplementation-validationimplementation-invaliddef" title="Example 2.12. Invalid ConstraintValidator definitions" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); ">Example 2.12, “Invalid ConstraintValidator definitions”</a>.</p><div class="example" style="font-family: sans-serif; font-size: 14px; "><a name="example-constraintsdefinitionimplementation-validationimplementation-invaliddef" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); "></a><p class="title" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); margin-top: 10px; padding-top: 5px; font-weight: bold; "><b style="font-family: sans-serif; font-size: 14px; ">Example 2.12. Invalid ConstraintValidator definitions</b></p><pre class="programlisting" style="font-size: 100%; padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-top-color: rgb(204, 204, 204); border-right-color: rgb(204, 204, 204); border-bottom-color: rgb(204, 204, 204); border-left-color: rgb(204, 204, 204); background-color: rgb(244, 244, 244); font-family: monospace; width: auto; ">//parameterized type
public class SizeValidatorForString implements<Size, Collection<String> {...}
//parameterized type using unbounded wildcard
public class SizeValidatorForCollection implements<Size, Collection<?>> {...}
//parameterized type using bounded wildcard
public class SizeValidatorForCollection implements<Size, Collection<? extends Address>> {...}</pre></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in; font-family: sans-serif; font-size: 14px; padding-bottom: 5px; padding-left: 5px; padding-right: 5px; background-color: rgb(255, 255, 204); "><h3 class="title" style="font-family: sans-serif; color: rgb(0, 51, 153); font-size: 120%; margin-top: 10px; padding-top: 5px; font-weight: bold; ">Note</h3><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">This restriction is not a theoretical limitation and a future version of the specification will likely allow that in the future.</p><div><br></div><div><br></div><div><br></div></div><div><br class="webkit-block-placeholder"></div></span></div><div><br></div><div>[...]</div><div><br></div><div><br></div><div><span class="Apple-style-span" style="font-family: -webkit-sans-serif; font-size: 14px; "><div class="section" lang="en" style="font-family: sans-serif; font-size: 14px; "><div class="section" lang="en" style="font-family: sans-serif; font-size: 14px; "><div class="titlepage" style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "><h3 class="title" style="font-family: sans-serif; color: rgb(0, 51, 153); font-size: 120%; margin-top: 10px; padding-top: 5px; font-weight: bold; ">3.5.3. ConstraintValidator resolution algorithm</h3></div></div><div style="font-family: sans-serif; font-size: 14px; "></div></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">A constraint is associated to one or more <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> implementations. Each <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator<A, T></tt> accepts the type <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt>. The <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> executed depends on the type declared by the target hosting the constraint. For a given constraint evaluation, a single <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> is considered.</p><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">If the constraint is hosted on a class or an interface, the targeted type is the class or the interface. If the constraint is hosted on a class attribute, the type of the attribute is the targeted type. If the constraint is hosted on a getter, the return type of the getter is the targeted type.</p><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">The rules written below describe formally the following statement: the <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> chosen to validate a declared type <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> is the one where the type supported by the<tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> is a supertype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> and where there is no other <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> whose supported type is a supertype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> and not a supertype of the chosen<tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> supported type.</p><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">When validating a constraint A placed on a target declaring the type <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt>, the following resolution rules apply.</p><div class="itemizedlist" style="font-family: sans-serif; font-size: 14px; "><ul type="disc" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Primitive types are considered equivalent to their respective primitive wrapper class.</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">A <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator<A, U></tt> is said to be <span class="emphasis" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><em style="font-family: sans-serif; font-size: 14px; ">compliant</em></span> with <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> if <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> is a subtype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">U</tt> (according to the<a href="http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.10" target="_top" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); "> Java Language Specification 3rd edition chapter 4.10 Subtyping</a>). Note that <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> is a subtype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">U</tt> if <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> = <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">U</tt>.</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">If no <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> compliant with <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> is found amongst the <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt>s listed by the constraint <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">A</tt>, a <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">UnexpectedTypeForConstraintException</tt> is raised.</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">A <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator<A, U></tt> compliant with <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> is considered <span class="emphasis" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><em style="font-family: sans-serif; font-size: 14px; ">strictly more specific</em></span> than a <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator<A, V></tt> compliant with <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> if <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">U</tt> is a strict subtype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">V</tt>. <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">U</tt> is a strict subtype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">V</tt> if <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">U</tt> is a subtype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">V</tt> and <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">U</tt> != <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">V</tt> (according to the<a href="http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#4.10" target="_top" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); ">Java Language Specification 3rd edition chapter 4.10 Subtyping</a>).</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">A <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator<A, U></tt> compliant with <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> is considered maximally specific if no other <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator<A, V></tt> compliant with <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">T</tt> is strictly more specific than<tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator<A, U></tt>.</p></li><li style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); "><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">If more than one maximally specific <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> is found, a <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">AmbiguousConstraintUsageException</tt> is raised.</p></li></ul></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in; font-family: sans-serif; font-size: 14px; padding-bottom: 5px; padding-left: 5px; padding-right: 5px; background-color: rgb(255, 255, 204); "><h3 class="title" style="font-family: sans-serif; color: rgb(0, 51, 153); font-size: 120%; margin-top: 10px; padding-top: 5px; font-weight: bold; ">Note</h3><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">While the Java compiler itself cannot determine if a constraint declaration will lead to a <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">UnexpectedTypeForConstraintException</tt> or a<tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">AmbiguousConstraintUsageException</tt>, rules can be statically checked. A tool such as an IDE or a Java 6 annotation processor can apply these rules and prevent a compilation in case of ambiguity. The specification encourages Bean Validation provider to provide such a tool to their users.</p></div><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Let's see a couple of declaration their respective <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> resolution. Assuming the following definitions:</p><pre class="programlisting" style="font-size: 100%; padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-top-color: rgb(204, 204, 204); border-right-color: rgb(204, 204, 204); border-bottom-color: rgb(204, 204, 204); border-left-color: rgb(204, 204, 204); background-color: rgb(244, 244, 244); font-family: monospace; width: auto; ">[...]
@Constraint(validatedBy={
SizeValidatorForCollection.class,
SizeValidatorForSet.class,
SizeValidatorForSerializable.class })
public @interface Size { ...}
public class SizeValidatorForCollection implements ConstraintValidator<Size, Collection> { ... }
public class SizeValidatorForSet implements ConstraintValidator<Size, Set> { ... }
public class SizeValidatorForSerializable implements ConstraintValidator<Size, Serializable> { ... }
public interface SerializableCollection extends Serializable, Collection {}</pre><p style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">The following resolutions occur.</p><div class="table" style="font-family: sans-serif; font-size: 14px; "><a name="d0e1999" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 204); "></a><p class="title" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); margin-top: 10px; padding-top: 5px; font-weight: bold; "><b style="font-family: sans-serif; font-size: 14px; ">Table 3.1. Resolution of ConstraintValidator for various constraints declarations</b></p><table summary="Resolution of ConstraintValidator for various constraints
declarations" border="1" style="font-family: sans-serif; font-size: 14px; border-collapse: collapse; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; empty-cells: hide; width: 100%; "><colgroup style="font-family: sans-serif; font-size: 14px; "><col align="center" style="font-family: sans-serif; font-size: 14px; "><col style="font-family: sans-serif; font-size: 14px; "></colgroup><thead style="font-family: sans-serif; font-size: 14px; "><tr style="font-family: sans-serif; font-size: 14px; "><th align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Declaration</th><th style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); ">Resolution</th></tr></thead><tbody style="font-family: sans-serif; font-size: 14px; "><tr style="font-family: sans-serif; font-size: 14px; "><td align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="code" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Size Collection getAddresses() { ... }</tt></td><td style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">SizeValidatorForCollection</tt>: direct match</td></tr><tr style="font-family: sans-serif; font-size: 14px; "><td align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="code" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Size Collection<?> getAddresses() { ... }</tt></td><td style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">SizeValidatorForCollection</tt>: <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Collection</tt> is a direct supertype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Collection<?></tt></td></tr><tr style="font-family: sans-serif; font-size: 14px; "><td align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="code" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Size Collection<Address> getAddresses() { ... }</tt></td><td style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">SizeValidatorForCollection</tt>: <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Collection</tt> is a direct supertype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Collection<Address></tt></td></tr><tr style="font-family: sans-serif; font-size: 14px; "><td align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="code" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Size Set<Address> getAddresses() { ... }</tt></td><td style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">SizeValidatorForSet</tt>: direct supertype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Set<Address></tt></td></tr><tr style="font-family: sans-serif; font-size: 14px; "><td align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="code" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Size SortedSet<Address> getAddresses() { ... }</tt></td><td style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">SizeValidatorForSet</tt>: <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Set</tt> is the closest supertype of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">SortedSet<Address></tt></td></tr><tr style="font-family: sans-serif; font-size: 14px; "><td align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="code" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Size SerializableCollection getAddresses() { ... }</tt></td><td style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">AmbiguousConstraintUsageException</tt><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">SerializableCollection</tt> is a subtype of both <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Collection</tt> and <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Serializable</tt> and neither<tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Collection</tt> nor <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">Serializable</tt> are subtypes of each other.</td></tr><tr style="font-family: sans-serif; font-size: 14px; "><td align="center" style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="code" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">@Size String getName() { ... }</tt></td><td style="font-family: sans-serif; font-size: 14px; color: rgb(0, 0, 0); padding-top: 4pt; padding-right: 4pt; padding-bottom: 4pt; padding-left: 4pt; "><tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">UnexpectedTypeForConstraintException</tt> none of the <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">ConstraintValidator</tt> types are supertypes of <tt class="classname" style="font-size: 100%; color: rgb(17, 17, 17); font-family: monospace; ">String</tt>.</td></tr></tbody></table></div></div></div><div class="section" lang="en" style="font-family: sans-serif; font-size: 14px; "><div class="titlepage" style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "><div style="font-family: sans-serif; font-size: 14px; "></div></div></div></div></span></div><div><br></div><div><br></div><div><br></div><div>[...]</div><div><br></div><div><span class="Apple-style-span" style="font-family: -webkit-sans-serif; font-size: 14px; "><pre class="programlisting" style="font-size: 100%; padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; border-top-style: solid; border-right-style: solid; border-bottom-style: solid; border-left-style: solid; border-top-width: 1px; border-right-width: 1px; border-bottom-width: 1px; border-left-width: 1px; border-top-color: rgb(204, 204, 204); border-right-color: rgb(204, 204, 204); border-bottom-color: rgb(204, 204, 204); border-left-color: rgb(204, 204, 204); background-color: rgb(244, 244, 244); font-family: monospace; width: auto; ">public interface ConstraintDescriptor {
/**
* Returns the annotation describing the constraint declaration.
* If a composing constraint, parameter values are reflecting
* the overridden parameters from the main constraint
*
* @return The annotation for this constraint.
*/
Annotation getAnnotation();
/**
* @return The groups the constraint is applied on.
*/
Set<Class<?>> getGroups();
/**
* @return the constraint validation implementation class
*/
Class<? extends ConstraintValidator<?,?>>[]
getConstraintValidatorClasses();
</pre><div><font class="Apple-style-span" face="-webkit-monospace"><span class="Apple-style-span" style="white-space: pre; "><br></span></font></div></span></div><div></div></body></html>