Load local json and feed to accumulo instance

FileHelpers.java

package one.flak.flinkgeomesa;

import com.google.gson.JsonElement;
import com.google.gson.JsonParser;

import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;

/**
 * Created by sb on 16.05.17.
 */
public class FileHelpers {

    public static JsonElement readJsonFromFile(String filePath) {
        String jsonString;
        try {
            jsonString = new String(Files.readAllBytes(Paths.get(filePath)), Charset.forName("UTF-8"));
        } catch(IOException e) {
            jsonString = "";
        }

        if(jsonString.isEmpty()) {
            return null;
        } else {
            return new JsonParser().parse(jsonString);
        }
    }

}

JsonToAccumuloConverter.java

package one.flak.flinkgeomesa;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.vividsolutions.jts.geom.Geometry;
import org.apache.commons.cli.BasicParser;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.Options;
import org.geotools.data.*;
import org.geotools.data.simple.SimpleFeatureStore;
import org.geotools.feature.DefaultFeatureCollection;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.FeatureIterator;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.filter.text.cql2.CQL;
import org.joda.time.DateTime;
import org.locationtech.geomesa.utils.interop.WKTUtils;
import org.opengis.feature.Feature;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.filter.Filter;

import java.io.IOException;
import java.util.Date;
import java.util.Map;

public class JsonToAccumuloConverter {

    public static void main(String[] args) throws Exception {
        System.out.println("READ CMDLINE OPTIONS");
        CommandLine cmd = getCmdLineOptions(args);

        System.out.println("ACCESSING DATA STORE");
        DataStore dataStore = getAccumuloDataStore(cmd);

        String filename = cmd.getOptionValue("filePath", "/Users/sb/Development/diploma-thesis/20160901/75226.json");

        JsonArray tripSamples = FileHelpers.readJsonFromFile(filename).getAsJsonArray();

        // establish specifics concerning the SimpleFeatureType to store
        SimpleFeatureType simpleFeatureType = AccumuloConfig.createSimpleFeatureType(AccumuloConfig.SIMPLE_FEATURE_TYPE_NAME);

        DefaultFeatureCollection featureCollection = new DefaultFeatureCollection();

        Object[] emptyFeature = {};
        String tripIdentifier = "75226";

        for(JsonElement sample : tripSamples) {
            SimpleFeature simpleFeature = SimpleFeatureBuilder.build(simpleFeatureType, emptyFeature, null);

            JsonObject json = sample.getAsJsonObject();
            long rawTimestamp = (long)(json.get("timestamp").getAsDouble() * 1000);
            double latitude = Double.parseDouble(json.get("latitude").getAsString());
            double longitude = Double.parseDouble(json.get("longitude").getAsString());
            double accelerationZ = Double.parseDouble(json.get("accl_z").getAsString());

            simpleFeature.setAttribute("OccuredAt", new DateTime().withMillis(rawTimestamp).toDate());
            simpleFeature.setAttribute("TripIdentifier", tripIdentifier);
            simpleFeature.setAttribute("AccelerationZ", accelerationZ);

            Geometry geometry = WKTUtils.read("POINT(" + latitude + " " + longitude + ")");
            simpleFeature.setAttribute("SamplePosition", geometry);

            featureCollection.add(simpleFeature);

            System.out.println(
                "TripId " + tripIdentifier + " | " +
                "OccuredAt " + new Date(rawTimestamp) + " | " +
                "Position " + latitude + " / " + longitude + " | " +
                "AccelerationZ " + accelerationZ + " | "
            );
        }

        System.out.printf("INSERTING %d samples ...", tripSamples.size());
        insertFeatures(AccumuloConfig.SIMPLE_FEATURE_TYPE_NAME, dataStore, featureCollection);
        System.out.println("DONE");

        System.out.println("Reading some values ...");

        Filter filter = CQL.toFilter("INCLUDE");

        Query query = new Query(AccumuloConfig.SIMPLE_FEATURE_TYPE_NAME, filter);
        FeatureSource source = dataStore.getFeatureSource(AccumuloConfig.SIMPLE_FEATURE_TYPE_NAME);

        FeatureIterator features = source.getFeatures(query).features();


        while(features.hasNext()) {
            Feature feature = features.next();

            System.out.println(
                    "TripId " + feature.getProperty("TripIdentifier").getValue() + " | " +
                    "OccuredAt " + feature.getProperty("OccuredAt").getValue() + " | " +
                    "Position " + feature.getProperty("SamplePosition").getValue() + " | " +
                    "AccelerationZ " + feature.getProperty("AccelerationZ").getValue() + " | "
            );

        }
        features.close();
        dataStore.dispose();
    }


    static void insertFeatures(String simpleFeatureTypeName,
                               DataStore dataStore,
                               FeatureCollection featureCollection)
            throws IOException {

        FeatureStore featureStore = (SimpleFeatureStore) dataStore.getFeatureSource(simpleFeatureTypeName);

        featureStore.addFeatures(featureCollection);
    }

    static CommandLine getCmdLineOptions(String[] args) throws Exception {
        // find out where -- in Accumulo -- the user wants to store data
        CommandLineParser parser = new BasicParser();
        Options options = AccumuloConfig.getCommonRequiredOptions();
        CommandLine cmd = parser.parse( options, args);

        return cmd;
    }

    static DataStore getAccumuloDataStore(CommandLine cmd) throws Exception {
        // verify that we can see this Accumulo destination in a GeoTools manner
        Map<String, String> dsConf = AccumuloConfig.getAccumuloDataStoreConf(cmd);
        DataStore dataStore = DataStoreFinder.getDataStore(dsConf);

        assert dataStore != null;

        return dataStore;
    }

}