Metacat

package edu.ucsb.nceas.metacat.annotation;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import net.minidev.json.JSONArray;

import net.minidev.json.JSONObject;

import net.minidev.json.JSONValue;

import org.apache.commons.httpclient.HttpClient;

import org.apache.commons.httpclient.HttpMethod;

import org.apache.commons.httpclient.methods.GetMethod;

import org.apache.commons.io.IOUtils;

import org.apache.log4j.Logger;

import edu.ucsb.nceas.metacat.properties.PropertyService;

public class AnnotatorService {

	private static Logger logMetacat = Logger.getLogger(AnnotatorService.class);

    /**

	 * Look up annotations from annotator service

	 * @see "http://docs.annotatorjs.org/en/latest/storage.html"

	 * @param pid the identifier to fetch annotations about

	 * @return

	 */

	public static Map<String, List<Object>> lookUpAnnotations(String pid) {

		String annotatorUrl = null;

		String consumerKey = null;

		try {

			annotatorUrl = PropertyService.getProperty("annotator.store.url");

			consumerKey = PropertyService.getProperty("annotator.consumerKey");

			// skip if not configured to query the annotator-store

			if (annotatorUrl == null || annotatorUrl.length() == 0) {

				return null;

			}

			// TODO: query for matching PID only - wasting time iterating over full list

			//String urlParameters = "pid=" + URLEncoder.encode(pid, "UTF-8");

			String urlParameters = "consumer=" + consumerKey;

			String url = annotatorUrl + "?" + urlParameters;

			HttpClient client = new HttpClient();

			HttpMethod method = new GetMethod(url);

			method.addRequestHeader("Accept", "application/json");

			client.executeMethod(method);

			InputStream is = method.getResponseBodyAsStream();

			String results = IOUtils.toString(is, "UTF-8");

			logMetacat.debug("RESULTS: " + results);

			JSONObject jo = (JSONObject) JSONValue.parse(results);

			JSONArray rows = (JSONArray) jo.get("rows");

			int count = rows.size();

			Map<String, List<Object>> annotations = new HashMap<String, List<Object>>();

			List<Object> values = null;

			// default the tags to a catch-all dynamic field as we develop

			String solrKey = "annotation_sm";

			for (int i = 0; i < count; i++){

				JSONObject row = (JSONObject) rows.get(i);

				// skip this row if it is not about this pid

				// FIXME: Bug in annotator-store prevents effective search by pid

				String pidValue = row.get("pid").toString();

				if (!pidValue.equals(pid)) {

					continue;

				}

				// if the annotation told us the target index field, then use it

				Object field = row.get("field");

				if (field != null) {

					solrKey = field.toString();

				}

				values = annotations.get(solrKey);

				if (values == null) {

					values = new ArrayList<Object>();

				}

				String key = "tags";

				Object obj = row.get(key);

				if (obj instanceof JSONArray) {

					JSONArray tags = (JSONArray) row.get(key);

					values.addAll(tags);

				} else {

					String value = row.get(key).toString();

					values.add(value);

				}

				annotations.put(solrKey, values);

			}

			// just populate this one field for example

			return annotations;

		} catch (Exception e) {

			logMetacat.error("Could not lookup annotation using: " + annotatorUrl, e);

		}

		return null;

	}

}