LookupDimension.java 文件源码

/**
 * Build an extraction function model object.
 *
 * @return  Take the internal namespaces and construct a model object for the extraction functions.
 */
@JsonIgnore
@Override
public Optional<ExtractionFunction> getExtractionFunction() {

    List<ExtractionFunction> extractionFunctions = getNamespaces().stream()
            .map(
                    namespace -> new LookupExtractionFunction(
                            new NamespaceLookup(namespace),
                            false,
                            "Unknown " + namespace,
                            false,
                            true
                    )
            ).collect(Collectors.toList());

    return Optional.ofNullable(
            extractionFunctions.size() > 1 ?
                    new CascadeExtractionFunction(extractionFunctions) :
                    extractionFunctions.size() == 1 ? extractionFunctions.get(0) : null
    );
}