Java-Hadoop Map Reduce，输入错误，省略csv头

我是Hadoop和MapReduce的新手，通过实现这个程序，现在出现了一系列我不理解的错误

此程序使用具有以下结构的数据集：Barrios.csv

"Codigo de barrio";"Codigo de distrito al que pertenece";"Nombre de barrio";"Nombre acentuado del barrio";"Superficie (m2)";"Perimetro (m)"
"01";"01";"PALACIO             ";"PALACIO             ";"001471085";"005754"
"01";"02";"IMPERIAL            ";"IMPERIAL            ";"000967500";"004557"
"01";"03";"PACIFICO            ";"PACÍFICO            ";"000750065";"004005"
"01";"04";"RECOLETOS           ";"RECOLETOS           ";"000870857";"003927"
"01";"05";"EL VISO             ";"EL VISO             ";"001708046";"005269"
"01";"06";"BELLAS VISTAS       ";"BELLAS VISTAS       ";"000716261";"003443"
"01";"07";"GAZTAMBIDE          ";"GAZTAMBIDE          ";"000506596";"002969"
"01";"08";"EL PARDO            ";"EL PARDO            ";"187642916";"087125"
"01";"09";"CASA DE CAMPO       ";"CASA DE CAMPO       ";"017470075";"019233"
"01";"10";"LOS CARMENES        ";"LOS CÁRMENES        ";"001292235";"006186"
"01";"11";"COMILLAS            ";"COMILLAS            ";"000665999";"004257"
"01";"12";"ORCASITAS           ";"ORCASITAS           ";"001356371";"004664"
"01";"13";"ENTREVIAS           ";"ENTREVÍAS           ";"005996932";"011057"
"01";"14";"PAVONES             ";"PAVONES             ";"001016979";"004134"
"01";"15";"VENTAS              ";"VENTAS              ";"003198045";"008207"
"01";"16";"PALOMAS             ";"PALOMAS             ";"001128602";"004988"
"01";"17";"SAN ANDRES          ";"SAN ANDRÉS          ";"009192451";"013710"
"01";"18";"CASCO H.VALLECAS    ";"CASCO H.VALLECAS    ";"049359337";"031924"
"01";"19";"CASCO H.VICALVARO   ";"CASCO H.VICÁLVARO   ";"032924620";"033326"
"01";"20";"SIMANCAS            ";"SIMANCAS            ";"002278418";"006678"
"01";"21";"ALAMEDA DE OSUNA    ";"ALAMEDA DE OSUNA    ";"001961904";"006043"

这代表了马德里的不同地区，并显示了它们的一系列数据，如周长、总表面。。。等

在我的MapReduce程序中，我希望获得按“Codigo de barrio”分组的所有地区的promedium周长，例如，从所有“Codigo de barrio”等于1、然后等于2的地区获得promedium周长。。。etc（oerimeter是最后一列值

这是我的代码：

public class WordCount {

    private static final String SEPARATOR = ";";

        public static class BarrioMapper extends Mapper<Object, Text, IntWritable, IntWritable>{

        public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
            final String[] values = value.toString().split(SEPARATOR);

            final int grupoBarrio = Integer.parseInt(values[0]);
            final int perimetro = Integer.parseInt(values[5]);  

            context.write(new IntWritable(grupoBarrio), new IntWritable(perimetro));
        }  
    }

    public static class BarrioReducer extends Reducer<IntWritable,IntWritable,IntWritable,IntWritable> {
        private IntWritable result = new IntWritable();

        public void reduce(IntWritable key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
            int sum = 0;
            int contador = 0;

        for (IntWritable value : values) {
            sum += value.get();
            contador++;
        }

        if (contador > 0) {
            result.set(sum/contador);
            context.write(key, result);
        }
        }
    }

  public static void main(String[] args) throws Exception {
      Configuration conf = new Configuration();

      Job job = new Job(conf, "wordcount");
      job.setJarByClass(WordCount.class);
      job.setMapperClass(BarrioMapper.class);
      job.setCombinerClass(BarrioReducer.class);
      job.setReducerClass(BarrioReducer.class);
      job.setOutputKeyClass(IntWritable.class);
      job.setOutputValueClass(IntWritable.class);

      FileInputFormat.addInputPath(job, new Path(args[0]));
      FileOutputFormat.setOutputPath(job, new Path(args[1]));

      System.exit(job.waitForCompletion(true) ? 0 : 1);  
  }
}

这个错误是关于“Codigo de barrio”输入数据的错误，我不明白它是什么意思。 `您的拆分错误：

final int grupoBarrio = Integer.parseInt(values[0]);

---

第一行的值[0]是“Codigo de barrio”，您应该在csv文件中使用ommit头（第一行）-它不是数值，正如错误所说，您不能将头解析为整数

为了跳过该值，可以使用try-catch

try {
    final int grupoBarrio = Integer.parseInt(values[0]);
    final int perimetro = Integer.parseInt(values[5]);  

    context.write(new IntWritable(grupoBarrio), new IntWritable(perimetro));
} (NumberFormatException e) { }

---

或者你应该用没有标题的文件覆盖HDFS文件。

你知道如何省略它吗？我认为最好的选择应该是阅读这个问题：并在web中查看map reduce如何工作的许多示例；例如，你可以用不同的方式处理csv标题：手动删除它；尝试/catch parseInt方法；检查文本是否有效ue包含特定标签；阅读此问题：我认为这应该可以解决您的问题：）@fiticida下载文件，删除标题，然后在HDFS中覆盖它

try {
    final int grupoBarrio = Integer.parseInt(values[0]);
    final int perimetro = Integer.parseInt(values[5]);  

    context.write(new IntWritable(grupoBarrio), new IntWritable(perimetro));
} (NumberFormatException e) { }