DBpediaSpotlightClient.java Source code

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Here is the source code for DBpediaSpotlightClient.java

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/**
 * Copyright 2011 Pablo Mendes, Max Jakob
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.methods.GetMethod;
import org.dbpedia.spotlight.exceptions.AnnotationException;
import org.dbpedia.spotlight.model.DBpediaResource;
import org.dbpedia.spotlight.model.Text;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.File;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.LinkedList;
import java.util.List;

/**
 * Simple web service-based annotation client for DBpedia Spotlight.
 *
 * @author pablomendes, Joachim Daiber
 */

public class DBpediaSpotlightClient extends AnnotationClient {

    //private final static String API_URL = "http://jodaiber.dyndns.org:2222/";
    private final static String API_URL = "http://spotlight.dbpedia.org/";
    private static final double CONFIDENCE = 0.3;
    private static final int SUPPORT = 0;

    @Override
    public List<DBpediaResource> extract(Text text) throws AnnotationException {

        LOG.info("Querying API.");
        String spotlightResponse;
        try {
            GetMethod getMethod = new GetMethod(API_URL + "rest/annotate/?" + "confidence=" + CONFIDENCE
                    + "&support=" + SUPPORT + "&text=" + URLEncoder.encode(text.text(), "utf-8"));
            getMethod.addRequestHeader(new Header("Accept", "application/json"));

            spotlightResponse = request(getMethod);
        } catch (UnsupportedEncodingException e) {
            throw new AnnotationException("Could not encode text.", e);
        }

        assert spotlightResponse != null;

        JSONObject resultJSON = null;
        JSONArray entities = null;

        try {
            resultJSON = new JSONObject(spotlightResponse);
            entities = resultJSON.getJSONArray("Resources");
        } catch (JSONException e) {
            throw new AnnotationException("Received invalid response from DBpedia Spotlight API.");
        }

        LinkedList<DBpediaResource> resources = new LinkedList<DBpediaResource>();
        for (int i = 0; i < entities.length(); i++) {
            try {
                JSONObject entity = entities.getJSONObject(i);
                resources.add(new DBpediaResource(entity.getString("@URI"),
                        Integer.parseInt(entity.getString("@support"))));

            } catch (JSONException e) {
                LOG.error("JSON exception " + e);
            }

        }

        return resources;
    }

    public static void main(String[] args) throws Exception {

        DBpediaSpotlightClient c = new DBpediaSpotlightClient();

        //        File input = new File("/home/pablo/eval/manual/AnnotationText.txt");
        //        File output = new File("/home/pablo/eval/manual/systems/Spotlight.list");

        //File input = new File("/home/pablo/eval/cucerzan/cucerzan.txt");
        //File output = new File("/home/pablo/eval/cucerzan/systems/cucerzan-Spotlight.set");

        //        File input = new File("/home/pablo/eval/wikify/gold/WikifyAllInOne.txt");
        //        File output = new File("/home/pablo/eval/wikify/systems/Spotlight.list");

        File input = new File("/home/alexandre/Projects/test-files-spotlight/ExternalClients_TestFiles/Berlin.txt");
        File output = new File(
                "/home/alexandre/Projects/test-files-spotlight/ExternalClients_TestFiles/Spotlight.list");

        c.evaluate(input, output);

        //        SpotlightClient c = new SpotlightClient(api_key);
        //        List<DBpediaResource> response = c.extract(new Text(text));
        //        PrintWriter out = new PrintWriter(manualEvalDir+"AnnotationText-Spotlight.txt.set");
        //        System.out.println(response);

    }

}