be.ugent.rml.functions.FunctionUtils Maven / Gradle / Ivy
package be.ugent.rml.functions;
import java.util.ArrayList;
import java.util.List;
public class FunctionUtils {
/**
* Generates strings from a function object. Possible lists/sets/bags/... in the object are unrolled recursively
* and a string value is generated from each "simple" (i.e., not a list/set/bag/...) child object.
*
* @param o Function object, can be iterable.
* @param result A string list to which string values of objects are added
*/
public static List functionObjectToList(Object o) {
final List result = new ArrayList<>();
if (o != null) {
// if o has child objects, recursively call this function on each child
if (o instanceof Iterable) {
((Iterable) o).forEach(item -> {
result.addAll(functionObjectToList(item));
});
// Some functions return a regular Array, not an Iterable, handle those as well.
} else if (o instanceof Object[]) {
for (Object item: (Object[])o)
result.addAll(functionObjectToList(item));
}
// if o has no children, call toString() to serialize it into a string
else {
// numeric and boolean types are trivially serialized correctly
// times/dates objects in the java.time package use the relevant ISO-8601 standard,
// which is also used by xsd types and thus RDF types
result.add(o.toString());
}
}
return result;
}
}