public static class MapClass extends MapReduceBase implements
Mapper<LongWritable, Text, Text, IntWritable> {
private Text word = new Text();
public void map(LongWritable key, Text value,
OutputCollector<Text, IntWritable> output,
Reporter reporter) throws IOException {
String line = value.toString();
String num = Integer.parseInt(line);
IntWritable one = new IntWritable(num);
word.set(“key”);
output.collect(word, one);
}
}
public static class Reduce extends MapReduceBase implements
Reducer<Text, IntWritable, Text, IntWritable> {
public void reduce(Text key, Iterator<IntWritable> values,
OutputCollector<Text, IntWritable> output, Reporter reporter)
throws IOException {
int sum = 0;
int count = 0;
int avg = 0;
while (values.hasNext()) {
sum += values.next().get();
count++;
}
avg = sum/count;
output.collect(key, new IntWritable(count));
}
}
看到output.collect()特别,我打印键&计数值.. 对于任何输入文件,输出为 键2 请帮我... (如何输出始终是2,即使100号作为输入??)map-reduce代码的输出是什么?
conf.setOutputKeyClass(Text.class); conf.setOutputValueClass(IntWritable.class); conf.setMapperClass(MapClass.class); conf.setCombinerClass(Reduce.class); conf.setReducerClass(Reduce.class); – Amnesiac
你可以编辑你的问题。不要垃圾评论。 – Jeremy
我没有发表任何评论.. – Amnesiac