D-Net

package eu.dnetlib.pace.clustering;

import com.google.common.collect.Sets;

import java.net.MalformedURLException;

import java.net.URL;

import java.util.Collection;

import java.util.Map;

public class UrlClustering extends AbstractClusteringFunction {

    public UrlClustering(Map<String, Integer> params) {

        super(params);

    }

    @Override

    protected Collection<String> doApply(String s) {

        return Sets.newHashSet(asUrl(s).getHost());

    }

    private URL asUrl(final String value) {

        try {

            return new URL(value);

        } catch (MalformedURLException e) {

            // should not happen as checked by pace typing

            throw new IllegalStateException("invalid URL: " + value);

        }

    }

}

import java.util.function.Predicate;

		fields.stream().filter(f -> !f.isEmpty()).forEach(f -> c.addAll(filterBlacklisted(doApply(filterStopWords(normalize(f.stringValue()), stopwords)), ngramBlacklist)));

	acronyms, ngrams, ngrampairs, sortedngrampairs, suffixprefix, spacetrimmingfieldvalue, immutablefieldvalue, personhash, personclustering, lowercase, urlclustering