org.apache.gobblin.converter.csv.CsvToJsonConverter.java Source code

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Here is the source code for org.apache.gobblin.converter.csv.CsvToJsonConverter.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.gobblin.converter.csv;

import org.apache.gobblin.converter.Converter;
import org.apache.gobblin.converter.SingleRecordIterable;
import java.io.IOException;
import java.util.List;

import com.google.common.base.Strings;
import com.google.common.collect.Lists;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonNull;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

import org.apache.gobblin.configuration.ConfigurationKeys;
import org.apache.gobblin.configuration.WorkUnitState;
import org.apache.gobblin.converter.DataConversionException;
import org.apache.gobblin.converter.SchemaConversionException;
import org.apache.gobblin.source.extractor.utils.InputStreamCSVReader;

public class CsvToJsonConverter extends Converter<String, JsonArray, String, JsonObject> {
    private static final String NULL = "null";

    /**
     * Take in an input schema of type string, the schema must be in JSON format
     * @return a JsonArray representation of the schema
     */
    @Override
    public JsonArray convertSchema(String inputSchema, WorkUnitState workUnit) throws SchemaConversionException {
        JsonParser jsonParser = new JsonParser();
        JsonElement jsonSchema = jsonParser.parse(inputSchema);
        return jsonSchema.getAsJsonArray();
    }

    /**
     * Takes in a record with format String and splits the data based on SOURCE_SCHEMA_DELIMITER
     * Uses the inputSchema and the split record to convert the record to a JsonObject
     * @return a JsonObject representing the record
     * @throws DataConversionException
     */
    @Override
    public Iterable<JsonObject> convertRecord(JsonArray outputSchema, String inputRecord, WorkUnitState workUnit)
            throws DataConversionException {
        try {
            String strDelimiter = workUnit.getProp(ConfigurationKeys.CONVERTER_CSV_TO_JSON_DELIMITER);
            if (Strings.isNullOrEmpty(strDelimiter)) {
                throw new IllegalArgumentException("Delimiter cannot be empty");
            }
            InputStreamCSVReader reader = new InputStreamCSVReader(inputRecord, strDelimiter.charAt(0),
                    workUnit.getProp(ConfigurationKeys.CONVERTER_CSV_TO_JSON_ENCLOSEDCHAR,
                            ConfigurationKeys.DEFAULT_CONVERTER_CSV_TO_JSON_ENCLOSEDCHAR).charAt(0));
            List<String> recordSplit;
            recordSplit = Lists.newArrayList(reader.splitRecord());
            JsonObject outputRecord = new JsonObject();

            for (int i = 0; i < outputSchema.size(); i++) {
                if (i < recordSplit.size()) {
                    if (recordSplit.get(i) == null) {
                        outputRecord.add(outputSchema.get(i).getAsJsonObject().get("columnName").getAsString(),
                                JsonNull.INSTANCE);
                    } else if (recordSplit.get(i).isEmpty() || recordSplit.get(i).toLowerCase().equals(NULL)) {
                        outputRecord.add(outputSchema.get(i).getAsJsonObject().get("columnName").getAsString(),
                                JsonNull.INSTANCE);
                    } else {
                        outputRecord.addProperty(
                                outputSchema.get(i).getAsJsonObject().get("columnName").getAsString(),
                                recordSplit.get(i));
                    }
                } else {
                    outputRecord.add(outputSchema.get(i).getAsJsonObject().get("columnName").getAsString(),
                            JsonNull.INSTANCE);
                }
            }

            return new SingleRecordIterable<>(outputRecord);
        } catch (Exception e) {
            throw new DataConversionException(e);
        }
    }
}