org.jvalue.ods.processor.adapter.CsvSourceAdapter.java Source code

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Here is the source code for org.jvalue.ods.processor.adapter.CsvSourceAdapter.java

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/*
Open Data Service
Copyright (C) 2013  Tsysin Konstantin, Reischl Patrick
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.
    
You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.jvalue.ods.processor.adapter;

import com.codahale.metrics.MetricRegistry;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.google.inject.Inject;
import com.google.inject.assistedinject.Assisted;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVRecord;
import org.jvalue.ods.api.sources.DataSource;

import java.io.IOException;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Iterator;

final class CsvSourceAdapter extends AbstractSourceAdapter {

    private final CSVFormat csvFormat;

    @Inject
    CsvSourceAdapter(@Assisted DataSource source,
            @Assisted(SourceAdapterFactory.ARGUMENT_SOURCE_URL) String sourceUrl,
            @Assisted(SourceAdapterFactory.ARGUMENT_CSV_FORMAT) String csvFormatString, MetricRegistry registry) {

        super(source, sourceUrl, registry);
        switch (csvFormatString) {
        case "DEFAULT":
            csvFormat = CSVFormat.DEFAULT;
            break;

        case "EXCEL":
            csvFormat = CSVFormat.EXCEL;
            break;

        case "MYSQL":
            csvFormat = CSVFormat.MYSQL;
            break;

        case "RFC4180":
            csvFormat = CSVFormat.RFC4180;
            break;

        case "TDF":
            csvFormat = CSVFormat.TDF;
            break;

        default:
            throw new IllegalArgumentException("unknown csv format \"" + csvFormatString + "\"");
        }
    }

    @Override
    protected SourceIterator doCreateIterator(DataSource source, URL sourceUrl, MetricRegistry registry) {
        return new CsvSourceIterator(source, sourceUrl, csvFormat, registry);
    }

    private static final class CsvSourceIterator extends SourceIterator {

        private Iterator<CSVRecord> csvIterator;
        private CSVRecord firstRecord;

        public CsvSourceIterator(DataSource source, URL sourceUrl, CSVFormat csvFormat, MetricRegistry registry)
                throws SourceAdapterException {
            super(source, sourceUrl, registry);
            try {
                CSVParser parser = CSVParser.parse(sourceUrl, Charset.forName("UTF-8"), csvFormat);
                csvIterator = parser.iterator();
                firstRecord = csvIterator.next();
            } catch (IOException ioe) {
                throw new SourceAdapterException(ioe);
            }
        }

        @Override
        protected boolean doHasNext() {
            return csvIterator.hasNext();
        }

        @Override
        protected ObjectNode doNext() {
            return createObject(firstRecord, csvIterator.next());
        }

        private ObjectNode createObject(CSVRecord keys, CSVRecord values) {
            ObjectNode node = new ObjectNode(JsonNodeFactory.instance);
            for (int i = 0; i < keys.size(); ++i) {
                node.put(keys.get(i), values.get(i));
            }
            return node;
        }

    }

}