[eclipselink-users] JpaCriteriaBuilder and Predicate

[Edward Mann <eclipselink@xxxxxxxxxx>]

I figured out how to get cast to work with JpaCriteriaBuilder. However
the question i have is that i had to add a
@SuppressWarnings("unchecked") to the method because of the message i
was getting "The expression of type Expression needs unchecked
conversion to conform to Expression<String>"

I could very well be doing something wrong, or imported/using the wrong
class.

/**
     * Iterate over the filters and add them to the List<Predicate>. For
the fields that we allow to be searched on
     * we are going to add special casting or some specific query
settings.
     * 
     * @param filters
     * @param cb
     * @param from
     * @return
     */
    @SuppressWarnings("unchecked")
    private List<Predicate> buildFilterPredicates(Map<String, String>
filters, JpaCriteriaBuilder cb, Root<Listing> from){
	List<Predicate> predicates = new ArrayList<Predicate>();
	for (Iterator<String> it = filters.keySet().iterator(); it.hasNext();)
{
	    String filterProperty = it.next(); // table column name = field
name
	    String filterValue = filters.get(filterProperty);
	    Expression<String> literal = cb
		    .literal(filterValue+"%");
	    switch (filterProperty) {
	    case "cmlMlsId":

predicates.add(cb.like(cb.fromExpression(cb.toExpression(from).get(filterProperty).cast("varchar")), literal));
		break;

	    default:
		predicates.add(cb.like(
			    from.<String> get(filterProperty), literal));
		break;
	    }
	}
	return predicates;
    }

Am i doing this the correct way? Do i need to provide a complete
example?

Thanks for any help.