[Simple-support] Constructor injection problems

[Andrew S. <and...@ti...>]

Hello, and thanks for this lightweight framework,

I'm having some problems with constructor injection for my immutable class.

My instance variables are all final, and are all serialised by Simple.
However, I don't need all the fields to be deserialised - some of the
fields are derived, being based on mathematical calculations of the other
fields. These derived variables are set in the constructor, based on the
parameters passed to the constructor.

It doesn't make logical sense to pass values of these derived variables
into the constructor, because they're not needed, and will be discarded.
However, I've got to do so, or I'll get a ConstructorException, saying "no
constructor accepts all read only values."

This isn't my production code, just an example:

public class calc
{
@Element(name="number")
private final int number;
@Element(name="numberSquared")
private final int numberSquared;

//extra constructor I have to provide
public Calc(@Element(name="number") int number,
@Element(name="numberSquared") int numberSquared)
{
this(number); //ignores numberSquared parameter, letting chained
constructor calculate value for itself
}

//usual constructor
Calc(int number)
{
this.number = number;
numberSquared = number * number; //ignoring parameter and calculating value
for itself
}

Unfortunately, even when I create this extra constructor, I still get a
PersistenceException: "Constructor not matched for class." As far as I can
see, I've annotated the constructor correctly, providing a parameter for
every possible field.

Short of me providing my actual code, is there anything I could look at
that might fix it?

As a suggestion, it might be useful for PersistenceException to provided
more specific information about how the constructor isn't matching.

Thanks,

Andrew