<Spring:bind> and constructing form backing object

[J_N]

We are beginning to use Spring in our j2ee application and have a few questions.
If I want to show a new form based on a complex nested object (for example A.B.C), I must fully construct it in formBackingObject() :

new A(...,new B(..., new C(...)))

If i construct the object only as

new A()

, it leads to NullValueInNestedPathException. Is our way showing new empty form the only one ?

And what about the opposite direction? What if C can be null and I don't fill its atributes in form? I get again in onSubmit() full object A.B.C, not only A.B with C set to null.

Is our way right or all this could be done better and simplier ?
Thanks.

[pmularien]

Unfortunately that is currently the way things work. To solve this problem:

And what about the opposite direction? What if C can be null and I don't fill its atributes in form? I get again in onSubmit() full object A.B.C, not only A.B with C set to null.

You'll have to have some way of "trimming" empty children from your object tree after going through the binding process.
Please see/vote for SPR-1671 so that this issue gets resolved