com.linkedin.pinot.tools.segment.converter.PinotSegmentToCsvConverter.java Source code

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Here is the source code for com.linkedin.pinot.tools.segment.converter.PinotSegmentToCsvConverter.java

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/**
 * Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
 *
 * 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.linkedin.pinot.tools.segment.converter;

import com.linkedin.pinot.core.data.GenericRow;
import com.linkedin.pinot.core.data.readers.PinotSegmentRecordReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.lang.StringUtils;

/**
 * The <code>PinotSegmentToCsvConverter</code> class is the tool to convert Pinot segment to CSV format.
 */
public class PinotSegmentToCsvConverter implements PinotSegmentConverter {
    private final String _segmentDir;
    private final String _outputFile;
    private final char _delimiter;
    private final char _listDelimiter;
    private final boolean _withHeader;

    PinotSegmentToCsvConverter(String segmentDir, String outputFile, char delimiter, char listDelimiter,
            boolean withHeader) {
        _segmentDir = segmentDir;
        _outputFile = outputFile;
        _delimiter = delimiter;
        _listDelimiter = listDelimiter;
        _withHeader = withHeader;
    }

    @Override
    public void convert() throws Exception {
        PinotSegmentRecordReader recordReader = new PinotSegmentRecordReader(new File(_segmentDir));
        try {
            recordReader.init();

            try (BufferedWriter recordWriter = new BufferedWriter(new FileWriter(_outputFile))) {
                if (_withHeader) {
                    GenericRow row = recordReader.next();
                    recordWriter.write(StringUtils.join(row.getFieldNames(), _delimiter));
                    recordWriter.newLine();
                    recordReader.rewind();
                }

                while (recordReader.hasNext()) {
                    GenericRow row = recordReader.next();
                    String[] fields = row.getFieldNames();
                    List<String> record = new ArrayList<>(fields.length);

                    for (String field : fields) {
                        Object value = row.getValue(field);
                        if (value instanceof Object[]) {
                            record.add(StringUtils.join((Object[]) value, _listDelimiter));
                        } else {
                            record.add(value.toString());
                        }
                    }

                    recordWriter.write(StringUtils.join(record, _delimiter));
                    recordWriter.newLine();
                }
            }
        } finally {
            recordReader.close();
        }
    }
}