window下eclipse配製hadoop外掛程式 （四）

標籤：

1.把外掛程式hadoop-eclipse-plugin-2.6.2.jar拷貝到eclipse安裝目錄下的plugins中

2.重啟一下Eclipse
配製hadoop

3.進入map/reduce視圖模式


4.向hadoop分布式儲存系統中存入資料

5.串連hadoop


6.建立hadoop工程

7.建立類MyWordCount.java

package com.yc.hadoop;import java.io.IOException;import org.apache.hadoop.conf.Configuration;import org.apache.hadoop.fs.Path;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.output.FileOutputFormat;public class MyWordCount {          public static class MyWordCountMapper extends Mapper<Object, Text, Text, IntWritable> {                private final static IntWritable one = new IntWritable(1);                private Text word = new Text();                public void map(Object key, Text value, Context context) throws IOException, InterruptedException {                      String[] words = value.toString().split("\\s");                      for (String w : words) {                            word.set(w);                            context.write(word, one);                      }                }          }          public static class MyWordCountReducer extends Reducer<Text, IntWritable, Text, IntWritable> {                private IntWritable result = new IntWritable();                public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {                      int sum = 0;                      for (IntWritable val : values) {                            sum += val.get();                      }                      result.set(sum);                      context.write(key, result);                }          }          public static void main(String[] args) throws Exception {                Configuration conf = new Configuration();                Job job = Job.getInstance(conf, "mywordcount");                job.setJarByClass(MyWordCount.class);                job.setMapperClass(MyWordCountMapper.class);                job.setCombinerClass(MyWordCountReducer.class);                job.setReducerClass(MyWordCountReducer.class);                job.setOutputKeyClass(Text.class);                job.setOutputValueClass(IntWritable.class);                FileInputFormat.addInputPath(job, new Path(args[0]));                FileOutputFormat.setOutputPath(job, new Path(args[1]));                System.exit(job.waitForCompletion(true) ? 0 : 1);          }    }

8.運行hadoop項目

window下eclipse配製hadoop外掛程式 （四）