org.sindice.siren.demo.ncpr.NCPRIndexer.java Source code

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Here is the source code for org.sindice.siren.demo.ncpr.NCPRIndexer.java

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/**
 * Copyright 2014 National University of Ireland, Galway.
 *
 * This file is part of the SIREn project. Project and contact information:
 *
 *  https://github.com/rdelbru/SIREn
 *
 * 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.
 */
package org.sindice.siren.demo.ncpr;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;

import org.apache.solr.client.solrj.SolrServer;
import org.apache.solr.client.solrj.SolrServerException;
import org.apache.solr.client.solrj.impl.HttpSolrServer;
import org.apache.solr.common.SolrInputDocument;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonProcessingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.io.LineReader;

/**
 * This class indexes the NCPR JSON dataset in a Solr example configured with
 * SIREn.
 */
public class NCPRIndexer {

    /**
     * URL of SIREn index
     */
    private final String INDEX_URL = "http://localhost:8983/solr/";

    private final SolrServer server;

    private final ObjectMapper mapper;

    private static final Logger logger = LoggerFactory.getLogger(NCPRIndexer.class);

    public NCPRIndexer() {
        this.server = new HttpSolrServer(INDEX_URL);
        this.mapper = new ObjectMapper();
    }

    /**
     * Reads and parses the input file line by line. Each line is expected to be a
     * serialised JSON object. It creates a {@link SolrInputDocument} for each
     * JSON object, add it to the index, and commit the documents at the end of
     * the process.
     */
    public void index(final File input) throws IOException, SolrServerException {
        logger.info("Loading JSON objects from {}", input);
        final LineReader reader = new LineReader(new FileReader(input));

        int counter = 0;
        String line;
        while ((line = reader.readLine()) != null) {
            server.add(this.parseObject(line));
            counter++;
        }
        server.commit();
        logger.info("Loaded {} JSON objects", counter);
    }

    /**
     * Parses a serialised JSON object and creates a {@link SolrInputDocument}
     * with two fields:
     * <ul>
     *  <li> <code>id</code> containing the id of the device
     *  <li> <code>name</code> containing the name of the device
     *  <li> <code>DeviceController_facet</code> containing the name of the device controller
     *  <li> <code>json</code> containing the serialised JSON object
     * </ul>
     */
    private SolrInputDocument parseObject(final String object) throws JsonProcessingException, IOException {
        final SolrInputDocument doc = new SolrInputDocument();
        final JsonNode node = mapper.readTree(object);
        doc.addField("id", node.path("ChargeDeviceId").asText());
        doc.addField("name", node.path("ChargeDeviceName").asText());
        doc.addField("DeviceController_facet", node.path("DeviceController").path("OrganisationName").asText());
        doc.addField("json", node);
        return doc;
    }

    public void close() {
        this.server.shutdown();
    }

    public static void main(final String[] args) throws JsonProcessingException, IOException, SolrServerException {
        final NCPRIndexer indexer = new NCPRIndexer();
        try {
            if (args.length == 0) {
                logger.error("Input file missing");
                System.exit(1);
            }
            indexer.index(new File(args[0]));
        } finally {
            indexer.close();
        }
    }

}