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  • MapReduce 中的Map后,sort不能对中文的key排序

    今天写了一个用mapreduce求平均分的程序,结果是出来了,可是没有按照“学生名字”进行排序,如果是英文名字的话,结果是排好序的。

    代码如下:

    package com.pro.bq;
    
    import java.io.IOException;
    import java.util.StringTokenizer;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.io.IntWritable;
    import org.apache.hadoop.io.Text;
    import org.apache.hadoop.mapreduce.Job;
    import org.apache.hadoop.mapreduce.Mapper;
    import org.apache.hadoop.mapreduce.Reducer;
    import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
    import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
    import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
    import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
    import org.apache.hadoop.util.GenericOptionsParser;
    import org.apache.hadoop.fs.Path;
    
    public class AverageScore {
        public static class MapAvg extends Mapper<Object, Text, Text, IntWritable>
        {
    
            public void map(Object key, Text value,Context context)
                    throws IOException, InterruptedException {  
    //            String[] lineData=value.toString().split(" ");//split中间如果有很多“ ”的话lineData的长度增加,灵活性差
    //            if(lineData.length==2)
    //            {        
    //                name.set(lineData[0]);
    //                score.set(Integer.parseInt(lineData[1]));
    //                context.write(name,score);
    //            } String line
    =value.toString(); StringTokenizer tokenizer=new StringTokenizer(line," "); while(tokenizer.hasMoreElements()) { StringTokenizer token=new StringTokenizer(tokenizer.nextToken()); Text name=new Text(token.nextToken()); IntWritable score=new IntWritable(Integer.parseInt(token.nextToken())); context.write(name,score); } } } public static class ReduceAvg extends Reducer<Text, IntWritable, Text, IntWritable> { public void reduce(Text key, Iterable<IntWritable> values,Context context) throws IOException, InterruptedException { // TODO Auto-generated method stub int sum=0; int cnt=0; for(IntWritable val:values) { sum+=val.get(); cnt++; } sum=(Integer)sum/cnt; context.write(key, new IntWritable(sum)); } } public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException { Configuration conf=new Configuration(); String[] hdfsPath=new String[]{"hdfs://localhost:9000/user/haduser/input/averageTest/","hdfs://localhost:9000/user/haduser/output/outAvgScore/"}; String[] otherArgs=new GenericOptionsParser(conf, hdfsPath).getRemainingArgs(); if(otherArgs.length!=2) { System.err.println("<in> <out>!!"); System.exit(2); } Job job=new Job(); job.setJarByClass(AverageScore.class); job.setMapperClass(MapAvg.class); job.setReducerClass(ReduceAvg.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(IntWritable.class); FileInputFormat.addInputPath(job, new Path(otherArgs[0])); FileOutputFormat.setOutputPath(job,new Path(otherArgs[1])); System.exit(job.waitForCompletion(true)?0:1); } }
    file1:
    zhangsan 33
    lisi 44
    wangwu 55
    zhaoliu 66
    
    file2:
    张三    4
    李四    1
    王五    2
    赵六    3
    
    file3:
    zhangsan 22
    lisi 33
    wangwu 44
    zhaoliu 55
    
    file4:
    李四 2
    张三 1
    王五 3
    赵六 4

    结果如下:

    lisi    38
    wangwu    49
    zhangsan    27
    zhaoliu    60
    张三    2
    李四    1
    王五    2
    赵六    3

    难道不支持中文的排序??以后学会自己写Partitioner后是不是可以自己写排序的程序??以后解决...

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  • 原文地址:https://www.cnblogs.com/wzyj/p/3558519.html
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