compare fails with big unsignedlongs

When code is generated based on the following part of the wsdl:

<s:restriction base="s:unsignedLong">
<s:minInclusive value="1"/>
<s:maxInclusive value="9999999999999999999"/>
</s:restriction>

org.apache.axis2.databinding.utils compare method will try to convert "9999999999999999999" string to java long type and will result in a NumberFormatException will be thrown although the number fits in a UnsignedLong type.

I think that it could be solved by using BigInteger instead of long as the java type for this comparissons.