You need to modify the package-info.java file that's generated as part of the entities that are required for your web service call. Modify the file as follows:
@javax.xml.bind.annotation.XmlSchema(
namespace = "some.ns",
elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED,
xmlns = {
@javax.xml.bind.annotation.XmlNs(
prefix = "sns",
namespaceURI = "some.ns")
})
package some.ns;