Hadoop和MapReduce(Hadoop and MapReduce)

 我是HDFS和MapReduce的新手，并试图计算调查统计数据。 输入文件采用以下格式：年龄点性别类别 - 所有4个都是数字。 这是正确的开始： 
 
    public static class MapClass extends MapReduceBase
    implements Mapper<IntWritable, IntWritable, IntWritable, IntWritable> {
    private final static IntWritable Age = new IntWritable(1) ;
    private IntWritable AgeCount = new IntWritable() ;

    public void map( Text key, Text value,
                    OutputCollector<IntWritable, IntWritable> output,
                    Reporter reporter) throws IOException {
        AgeCount. set(Integer. parseInt(value. toString() ) ) ;
        output. collect(AgeCount, Age) ;
    }
}
 
 我的问题：1。这是一个正确的开始吗？ 2.如果我想收集其他属性，如性，点 - 我会添加另一个output.collect语句吗？ 我知道我必须阅读该行并分成属性。 3.它表示实现Mapper - 我使所有4 IntWritable都正确吗？ 

I am new to HDFS and MapReduce and trying to calculate survey statistics. Input file is in this format: Age Points Sex Category - all 4 of them are numbers. Is this the correct start:
 
    public static class MapClass extends MapReduceBase
    implements Mapper<IntWritable, IntWritable, IntWritable, IntWritable> {
    private final static IntWritable Age = new IntWritable(1) ;
    private IntWritable AgeCount = new IntWritable() ;

    public void map( Text key, Text value,
                    OutputCollector<IntWritable, IntWritable> output,
                    Reporter reporter) throws IOException {
        AgeCount. set(Integer. parseInt(value. toString() ) ) ;
        output. collect(AgeCount, Age) ;
    }
}
 
My questions: 1. Is this a correct start? 2. If I want to collect for other attributes like Sex,Points - will I just add another output.collect statements? I know I have to read the line and split into attributes. 3. Where it says implements Mapper - I made all 4 IntWritable is it correct?

原文：https://stackoverflow.com/questions/5698693