我尝试实施的话由我自己算例如,这里是我的执行映射器:地图减少字数例如不工作
public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
Text word = new Text();
String line = value.toString();
StringTokenizer tokenizer = new StringTokenizer(line);
while (tokenizer.hasMoreTokens()) {
word.set(tokenizer.nextToken());
context.write(word, new IntWritable(1));
}
}
}
和减速机:
public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable> {
public void reduce(Text key, Iterator<IntWritable> values, Context context) throws IOException, InterruptedException {
int sum = 0;
while (values.hasNext())
sum += values.next().get();
context.write(key, new IntWritable(sum));
}
}
但输出我得到执行此代码看起来像只映射器的输出,例如,如果输入的是“世界你好你好”,输出将为
hello 1
hello 1
world 1
我也使用映射和缩减之间的组合器。任何人都可以解释我这个代码有什么问题吗?
非常感谢!
感谢。我被困在这个问题上一两天了。 – rOrlig 2011-04-26 02:12:05