mtsar.api.csv.WorkerRankingCSV.java Source code

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Here is the source code for mtsar.api.csv.WorkerRankingCSV.java

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/*
 * Copyright 2015 Dmitry Ustalov
 *
 * 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 mtsar.api.csv;

import mtsar.api.WorkerRanking;
import org.apache.commons.csv.CSVFormat;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.StandardCharsets;
import java.util.Collection;
import java.util.Comparator;

public class WorkerRankingCSV {
    private static final CSVFormat FORMAT = CSVFormat.EXCEL.withHeader();
    private static final String[] HEADER = { "worker_id", "reputation" };
    private static final Comparator<WorkerRanking> ORDER = (r1, r2) -> r1.getWorker().getId()
            .compareTo(r2.getWorker().getId());

    public static void write(Collection<WorkerRanking> rankings, OutputStream output) throws IOException {
        try (final Writer writer = new OutputStreamWriter(output, StandardCharsets.UTF_8)) {
            final Iterable<String[]> iterable = () -> rankings.stream().sorted(ORDER)
                    .map(aggregation -> new String[] { Integer.toString(aggregation.getWorker().getId()), // worker_id
                            Double.toString(aggregation.getReputation()) // reputation
                    }).iterator();

            FORMAT.withHeader(HEADER).print(writer).printRecords(iterable);
        }
    }
}