D-Net

package eu.dnetlib.dli.resolver;

import java.util.List;

import com.google.common.collect.Lists;

import com.google.gson.JsonArray;

import com.google.gson.JsonElement;

import com.google.gson.JsonObject;

import com.google.gson.JsonParser;

import eu.dnetlib.dli.resolver.model.*;

import eu.dnetlib.pid.resolver.AbstractPIDResolver;

import eu.dnetlib.pid.resolver.model.ObjectType;

import eu.dnetlib.pid.resolver.model.SubjectType;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

/**

 * The Class DataciteDOIResolver.

 */

public class DataciteResolver extends AbstractPIDResolver {

    public static final String DATACITE_NS_PREFIX = "datacite____";

    /**

     * The Constant log.

     */

    private static final Log log = LogFactory.getLog(DataciteResolver.class); // NOPMD by marko on 11/24/08 5:02 PM

    /**

     * The Constant baseURL.

     */

    private final static String baseURL = "http://search.datacite.org/api?wt=json&q=doi:";

    private DLIResolvedObject parseResponse(final String response) {

        if (response == null) return null;

        JsonElement jElement = new JsonParser().parse(response);

        JsonObject jobject = jElement.getAsJsonObject();

        if (jobject.has("response")) {

            long total = jobject.get("response").getAsJsonObject().get("numFound").getAsLong();

            if (total == 0) return null;

            DLIResolvedObject responseObj = new DLIResolvedObject();

            JsonElement hits = ((JsonObject) jobject.get("response")).get("docs");

            JsonArray hitsObject = hits.getAsJsonArray();

            for (final JsonElement elem : hitsObject) {

                String doi = ((JsonObject) elem).get("doi").getAsString();

                responseObj.setPid(doi);

                responseObj.setPidType("DOI");

                responseObj.setType(ObjectType.dataset);

                List<String> authors = Lists.newArrayList();

                List<String> titles = Lists.newArrayList();

                List<SubjectType> subjects = Lists.newArrayList();

                // ADDING SUBJECTS

                final JsonElement subjectElement = ((JsonObject) elem).get("subject");

                if (subjectElement != null) {

                    JsonArray subjectArray = subjectElement.getAsJsonArray();

                    for (int i = 0; i < subjectArray.size(); i++) {

                        subjects.add(new SubjectType("unknown", subjectArray.get(i).getAsString()));

                    }

                }

                responseObj.setSubjects(subjects);

                // ADDING TITLES

                JsonElement titleElement = ((JsonObject) elem).get("title");

                if (titleElement != null) {

                    JsonArray titleArray = titleElement.getAsJsonArray();

                    for (int i = 0; i < titleArray.size(); i++) {

                        titles.add(titleArray.get(i).getAsString());

                    }

                }

                responseObj.setTitles(titles);

                //ADDING DESCRIPTION

                JsonElement descriptionElement = ((JsonObject) elem).get("description");

                if (descriptionElement != null) {

                    JsonArray descriptionArray = descriptionElement.getAsJsonArray();

                    if (descriptionArray.size() > 0)

                        responseObj.setDescription(descriptionArray.get(0).getAsString());

                }

                // ADDING AUTHORS

                JsonElement contributorElement = ((JsonObject) elem).get("contributor");

                if (contributorElement != null) {

                    JsonArray contributorArray = contributorElement.getAsJsonArray();

                    for (int i = 0; i < contributorArray.size(); i++) {

                        authors.add(contributorArray.get(i).getAsString());

                    }

                }

                // ADDING AUTHORS

                JsonElement creatorElement = ((JsonObject) elem).get("creator");

                if (creatorElement != null) {

                    JsonArray creatorArray = creatorElement.getAsJsonArray();

                    for (int i = 0; i < creatorArray.size(); i++) {

                        authors.add(creatorArray.get(i).getAsString());

                    }

                }

                responseObj.setAuthors(authors);

                final DLIObjectProvenance provenance = new DLIObjectProvenance();

                DLIPIDResolver.setDatasourceProvenance(provenance, DATACITE_NS_PREFIX);

                final String dataCenter_symbol = ((JsonObject) elem).get("datacentre_symbol").getAsString();

                final String datacenter = ((JsonObject) elem).get("datacentre").getAsString();

                if (datacenter != null) {

                    final String publisher = datacenter.replace(dataCenter_symbol, "").replace("-", "").trim();

                    if (publisher != null && publisher.length() > 0) {

                        provenance.setPublisher(publisher);

                    }

                }

                responseObj.setDatasourceProvenance(Lists.newArrayList(provenance));

                responseObj.setCompletionStatus(CompletionStatus.complete.toString());

                return responseObj;

            }

            return null;

        }

        return null;

    }

    @Override

    protected boolean canResolvePid(final String pidType) {

        return (pidType != null) && ("doi".equals(pidType.toLowerCase().trim()) || "handle".equals(pidType.toLowerCase().trim()));

    }

    @Override

    protected DLIResolvedObject resolve(final String pid, final String pidType) {

        try {

            final String response = requestURL(baseURL + pid.replace(" ", "%20"));

            return parseResponse(response);

        } catch (Throwable e) {

            log.error("Error on getting item from url " + baseURL + pid.replace(" ", "%20"));

        }

        return null;

    }

}