double sum(String attrName)
The sum of the specified attribute from the list of the business objects.
UnknownAttributeException - When the specified attribute is not a valid attribute in the business objects passed in.
UnsupportedAttributeTypeException - When the type of the specified attribute is not one of the supported attribute types listed in the note section.
All of the above exceptions are subclassed from CollaborationException. The sum() method can set the following exception type for these exceptions: AttributeException.
double sumSalary = items.sum("Salary");