I spent a long time scrutinizing the spec for exception cases. This email list exceptional cases and propose to associate specific exceptions to them or not. Please review and tell me:
- if you think I forgot cases that needs additional consideration.
- which model you favor (see B)
A. EXCEPTION CASES
I described the error cases and a fine grained Exception model (see B) and have a few questions see ???
1. Error report
Use for other frameworks to report violation reports
**
* Report the result of constraint violations
*
* @author Emmanuel Bernard
*/
public class ConstraintViolationException extends ValidationException {
private final Set<ConstraintViolation> constraintViolations;
/**
* Creates a constraint violation report
*
* @param message error message
* @param constraintViolations Set of ConstraintViolation
*/
public ConstraintViolationException(String message, Set<ConstraintViolation> constraintViolations) {
super( message );
this.constraintViolations = constraintViolations;
}
/**
* Creates a constraint violation report
*
* @param constraintViolations Set of ConstraintViolation
*/
public ConstraintViolationException(Set<ConstraintViolation> constraintViolations) {
super();
this.constraintViolations = constraintViolations;
}
/**
* Set of constraint violations reported during a validation
*
* @return Set of CosntraintViolation
*/
public Set<ConstraintViolation> getConstraintViolations() {
return constraintViolations;
}
}
2. Execution exceptions
ie during validator.validate(...);
Constraint Declaration
These can be found a compilation time with an annotation processor or an IDE
??? UnsupportedTypeException or should it be AmbiguousConstraintUsageException
More than one ConstraintValidator targeting the same type
declared property type property has too many matches
UnsupportedTypeException
declared property type property has no match
ConstraintDefinitionException
composition parameter overriding (name, composing constraint or incompatible parameter types)
constraint composed of itself
Constraint implementation
ConstraintInitializationException
??? initialize() must raise a RTE will be wrapped OR should we not wrap
UnsupportedTypeException
isValid incompatible type (detected by impl) => same as "declared property type property has no match"
ConstraintExcecutionException
isValid throws a RTE will be wrapped into ConstraintValidatorExecutionException
ConstraintCreationException
ConstraintValidatorFactory fails with RTE. Wraps it.
??? should we collapse that into a ConstraintExecutionException or even ValidationException
Groups
Can be checked at built time by an IDE or an AnnotationProcessor
GroupDefinitionException
cyclic dependency between groups sequences and group inheritance
missing group X on a Default group overriding
Group sequence name used in a constraint declaration
group is not an interface
Various
IllegalArgumentException
if object to validate is null, or empty set?
??? Calls to SPi like MessageInterpolator / TraversableResolver should be wrapped?
3. Bootstrap
ProviderNotFoundException
cannot find matching provider
cannot find any provider
ConfigurationException
cannot read XML cong
more than one XML conf
no no-arg constructor on classes described by XML
MappingException
cannot read XML mapping
entity described more than once
field/getter described more than once
Wrong class / field / getter name
Wrong constraint declaration
Wrong constraint definition
B. EXCEPTION MODEL
We have three approaches:
1. specialize an exception when the application can do something about it
In this case all exceptions are ValidationException except ConstraintViolationException
2. specialize exceptions to provide informations to the user
ValidationException (root)
ConstraintViolationException
AmbiguousConstraintUsageException
UnsupportedTypeException
ConstraintDefinitionException
ConstraintInitializationException
ConstraintExcecutionException
ConstraintCreationException
GroupDefinitionException
ProviderNotFoundException
ConfigurationException
MappingException
3. a man in the middle approach with some exception collapsing
ValidationException (root)
ConstraintViolationException
ConstraintDeclarationException (instead of UnsupportedTypeException and AmbiguousConstraintUsageException)
ConstraintDefinitionException
ConstraintExcecutionException
ConfigurationException