Re: [eclipselink-users] MOXy: mapping constant values?

[Matt MacIvor <matt.macivor@xxxxxxxxxx>]

Hi Polly,

EclipseLink handles read-only mappings, but not really write-only 
mappings. The easiest thing to do here would be to set up a mapping for 
your constant value using method-access. Then in the getter you can just 
return your constant value, and in the setter you can do nothing. For 
example:

public String getMyConstant() {
 return "My Constant String";
}

public void setMyConstant() {
 //do nothing
}

When using method access for a mapping it's not required by the runtime 
that the variable actually exist on the class, but you may need to add 
the instance variable in order to create the mapping in the workbench.

A couple of updates about other issues you were seeing:
The default namespace issue has been fixed in the runtime, so you no 
longer need a prefix for each namespace. You can now set a default 
namespace on a NamespaceResolver. There's a separate bug that has been 
created for Workbench support (236491).

The bug about error handling in JAXBContext (236525) is being looked at now.

Hope this helps,

-Matt

amphoras wrote:

> Hi,
>
> The situation I have is that there are some constant values that I want to
> appear in my XML output document (like application=Foo).  I don't want this
> value to be affected by unmarshalling.  How does one map this kind of
> "constant"?
>
> After playing around with EclipseLink, it looks like even though this value
> is supposed to be a constant, I need to create a variable for it in my
> domain object in order to create a mapping to the proper XPath.  But then
> what should I do?  I don't want this variable's value to change by
> unmarshalling.  I can write an afterLoad method to reset the variable back
> to its original value.  That way when I marshall the object, the correct
> value will be output in the XML.  But is there a better way to do this? 
> Does EclipseLink support one-way mappings or marshalling constants?
>
> Thanks!
> --Polly
>