Spring Add support to any Iterable types on PropertyAccessor

Sometimes, for better clarity of the application model, we create objects that encapsulate a Collection, and this object comes to represent a collection of a certain type in the application model. To simplify for-each operations, this object must implement java.lang.Iterable. Example:

public class MyType {
    @NotNull
    private String name;
}

public class MyTypesGroup implements Iterable<MyType> {
    private Collection <MyType> myTypes = new ArrayList <MyType> ();

    @Override
    public Iterator<MyType> iterator() {
         return myTypes.iterator();
    }

    // model methods
}

public class MyAggregateType {
     @Valid
     private MyTypesGroup myTypesGroup MyTypesGroup = new ();
}

Databind, get and set properties operations, typically used with BeanWrapper, they are not supported for these objects (in the above example, something like "myTypesGroup[0].name").

In my use case, with Hibernate Validator, the path will be generated "myTypesGroup[0].name" (Hibernate Validator au), occurring an exception when the Spring tries to extract the property value (to generate the error message on the Spring MVC)

This pull request adds java.lang.Iterable as a supported type for reading properties by PropertyAccessors.

I have signed and agree to the terms of the Spring ICLA.

Thanks (and sorry for any English errors :))

Comment From: pivotal-issuemaster

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Comment From: pivotal-cla

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Comment From: jhoeller

As part of the wider binding and validation theme in 6.1, I've picked up this one in a custom fashion, unified with our Set/Collection handling (just doing the size check after the iteration rather than before).

Your pull request was a great starting point there, thanks for your efforts! Sorry for not revisiting it earlier...