Spring formatters for nulls values

I have a select control in my view and i want to "bind" or "format" the item "Please select an item" to a null value in my backing form object. Is that possible? because i know t开发者_开发百科hat making some traditional formatting doesn't work properly. Instead i saw an example of making changes in class GenericConversionService and using that class instead of the original. (unfortunately i can't find it anymore)

This is the exception when i return a null value from my formatter class:

org.springframework.core.convert.ConversionFailedException: Unable to convert value "-1" from type 'java.lang.String' to type 'com.tesisutn.restsoft.dominio.articulo.Marca'; nested exception is java.lang.NullPointerException

Thanks a lot in advance!

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It looks like your form is sending a -1 to indicate that "Please select an item" is selected.

• First thing you can try is to send noting. Then the binding (when the form is send to the server) will work, the according command object field will be null.

  <option value="">Please select an item</option>
  

• If this is no option for you (for example because you use dojo), then you need to implement your own property editor or conversation (Spring 3.0)