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Mapper鏄竴涓敤浜庡鐞哅ap闃舵鐨勭被銆備笅闈㈡槸浣跨敤Mapper鐨勪竴鑸楠わ細

1. 鍒涘缓涓€涓疄鐜颁簡org.apache.hadoop.mapreduce.Mapper鎺ュ彛鐨勭被锛屽苟閲嶅啓鍏朵腑鐨刴ap()鏂规硶銆?/span>

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3. 鍦╩ap()鏂规硶涓紝浣跨敤context.write(key, value)灏嗙敓鎴愮殑閿€煎杈撳嚭銆?/span>

4. 鍦ㄤ富绋嬪簭涓紝閰嶇疆鍜岃繍琛孧apReduce浣滀笟銆?/span>

浠ヤ笅鏄竴涓畝鍗曠殑绀轰緥锛屾紨绀轰簡濡備綍鍦↗ava涓娇鐢∕apper锛?/span>

import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
import java.io.IOException;
public class MyMapper extends Mapper<LongWritable, Text, Text, IntWritable> {
    private final static IntWritable one = new IntWritable(1);
    private Text word = new Text();
    @Override
    protected void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
        String line = value.toString();
        String[] words = line.split(" ");
        for (String word : words) {
            this.word.set(word);
            context.write(this.word, one);
        }
    }
}

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褰撶劧锛屽叿浣撶殑浣跨敤鏂瑰紡杩樺彇鍐充簬鎮ㄦ墍搴旂敤鐨勫満鏅拰妗嗘灦銆備笂杩扮ず渚嬮€傜敤浜嶩adoop MapReduce妗嗘灦銆傚鏋滄偍浣跨敤鍏朵粬妗?/span>鏋舵垨搴擄紝璇峰弬鑰冪浉搴旂殑鏂囨。鍜岀ず渚嬩唬鐮併€?/span>