com.ikanow.aleph2.analytics.hadoop.services.BeJsonParser.java Source code

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Here is the source code for com.ikanow.aleph2.analytics.hadoop.services.BeJsonParser.java

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/*******************************************************************************
 * Copyright 2015, The IKANOW Open Source Project.
 *
 * 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 com.ikanow.aleph2.analytics.hadoop.services;

import java.io.InputStream;
import java.util.Optional;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import scala.Tuple2;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.ikanow.aleph2.analytics.hadoop.data_model.IParser;
import com.ikanow.aleph2.core.shared.utils.BatchRecordUtils;
import com.ikanow.aleph2.data_model.interfaces.data_analytics.IBatchRecord;
import com.ikanow.aleph2.data_model.utils.BeanTemplateUtils;

/** Parser for reading in JSON data
 * @author Alex
 */
public class BeJsonParser implements IParser {
    protected static final Logger logger = LogManager.getLogger(BeJsonParser.class);

    private ObjectMapper _mapper = BeanTemplateUtils.configureMapper(Optional.empty());
    private JsonParser _parser = null;
    private JsonFactory _factory = null;

    @Override
    public boolean multipleRecordsPerFile() {
        return true;
    }

    @Override
    public Tuple2<Long, IBatchRecord> getNextRecord(long currentFileIndex, String fileName, InputStream inStream) {
        Tuple2<Long, IBatchRecord> t2 = null;
        try {
            if (null == _factory) {
                _factory = _mapper.getFactory();
            }
            if (null == _parser) {
                _parser = _factory.createParser(inStream);
            }
            JsonToken token = _parser.nextToken();
            while ((token != JsonToken.START_OBJECT) && (token != null)) {
                token = _parser.nextToken();
            }
            if (null == token) {
                _parser = null;
                return null; //EOF
            }
            JsonNode node = _parser.readValueAsTree();

            t2 = new Tuple2<Long, IBatchRecord>(currentFileIndex, new BatchRecordUtils.BatchRecord(node, null));
            return t2;

        } catch (Exception e) {
            // (this can often happen as an EOF condition)s
            _parser = null;
            return null; //EOF
        }
    }

    /* (non-Javadoc)
     * @see com.ikanow.aleph2.analytics.hadoop.data_model.IParser#handleThisPath(java.lang.String)
     */
    @Override
    public boolean handleThisPath(String path) {
        return path.endsWith(".json");
    }

}