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我有一个 6GB 的大 CSV 文件,以逗号分隔。下面是映射器功能

@Override
    public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        String[] tokens = value.toString().split(",");

        String crimeType = tokens[5].trim();      // column #5 is the crime type in the CSV file, serving key
//      int year = Integer.parseInt(tokens[17].trim()); // the year when the crime happened

        int year = 2010;

        CrimeTypeKey crimeTypeYearKey = new CrimeTypeKey(crimeType, year);

        context.write(crimeTypeYearKey, ONE);
}

如您所见,我使用“.split”来分解每一行(或每一列?)。我想知道在这种情况下如何使用 OpenCSV?请举个例子,非常感谢

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