Polish ConditionalGenericConverter documentation

Issue: SPR-13071
This commit is contained in:
Stephane Nicoll 2015-06-03 10:31:55 +02:00
parent e5f76af193
commit d6056182aa
1 changed files with 11 additions and 10 deletions

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@ -853,28 +853,29 @@ Favor Converter or ConverterFactory for basic type conversion needs.
[[core-convert-ConditionalGenericConverter-SPI]]
==== ConditionalGenericConverter
Sometimes you only want a Converter to execute if a specific condition holds true. For
example, you might only want to execute a Converter if a specific annotation is present
on the target field. Or you might only want to execute a Converter if a specific method,
such as static valueOf method, is defined on the target class.
ConditionalGenericConverter is an subinterface of GenericConverter that allows you to
define such custom matching criteria:
Sometimes you only want a `Converter` to execute if a specific condition holds true. For
example, you might only want to execute a `Converter` if a specific annotation is present
on the target field. Or you might only want to execute a `Converter` if a specific method,
such as a `static valueOf` method, is defined on the target class.
`ConditionalGenericConverter` is the union of the `GenericConverter` and
`ConditionalConverter` interfaces that allows you to define such custom matching criteria:
[source,java,indent=0]
[subs="verbatim,quotes"]
----
public interface ConditionalGenericConverter extends GenericConverter {
public interface ConditionalGenericConverter
extends GenericConverter, ConditionalConverter {
boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType);
}
----
A good example of a ConditionalGenericConverter is an EntityConverter that converts
A good example of a `ConditionalGenericConverter` is an EntityConverter that converts
between an persistent entity identifier and an entity reference. Such a EntityConverter
might only match if the target entity type declares a static finder method e.g.
findAccount(Long). You would perform such a finder method check in the implementation of
matches(TypeDescriptor, TypeDescriptor).
`findAccount(Long)`. You would perform such a finder method check in the implementation of
`matches(TypeDescriptor, TypeDescriptor)`.