windows下eclipse连接远程hadoop集群的开发配置

1，百度下载eclipse插件hadoop-eclipse-plugin-2.7.3.jar，放入eclipse安装目录下的plugins下，重启eclipse

2，配置hadoop在windows下的安装目录

windows-->preference-->Hadoop Map/Reduce

3,windows-->showview-->others-->Map/Reduce Location,配置hadoop location

与远程hadoop集群的core-site.xml中配置一致

4，刷新可见远程hdfs目录

5，右击NEW project -->maven Projcet,新建工程如下，可见，自动生成了hadoop开发依赖jar包

6，新建WordCount.java

package com.hadoop.example1;

import java.io.IOException;
import java.util.Iterator;
import java.util.StringTokenizer;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
public class WordCount {
    public static class Map extends MapReduceBase implements
            Mapper<LongWritable, Text, Text, IntWritable> {
        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();
        public void map(LongWritable key, Text value,
                OutputCollector<Text, IntWritable> output, Reporter reporter)
                throws IOException {
            String line = value.toString();
            StringTokenizer tokenizer = new StringTokenizer(line);
            while (tokenizer.hasMoreTokens()) {
                word.set(tokenizer.nextToken());
                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;
            while (values.hasNext()) {
                sum += values.next().get();
            }
            output.collect(key, new IntWritable(sum));
        }
    }
    public static void main(String[] args) throws Exception {
        JobConf conf = new JobConf(WordCount.class);
        conf.setJobName("wordcount");
        conf.setOutputKeyClass(Text.class);
        conf.setOutputValueClass(IntWritable.class);
        conf.setMapperClass(Map.class);
        conf.setCombinerClass(Reduce.class);
        conf.setReducerClass(Reduce.class);
        conf.setInputFormat(TextInputFormat.class);
        conf.setOutputFormat(TextOutputFormat.class);
        FileInputFormat.setInputPaths(conf, new Path(args[0]));
        FileOutputFormat.setOutputPath(conf, new Path(args[1]));
        JobClient.runJob(conf);
    }
}

7，下载添加必要的文件：
（1）在https://github.com/SweetInk/hadoop-common-2.7.1-bin中下载winutils.exe,libwinutils.lib 拷贝到%HADOOP_HOME%\bin目录
（2）在https://github.com/SweetInk/hadoop-common-2.7.1-bin中下载hadoop.dll，并拷贝到c:\windows\system32目录中。
注意：若不添加会出现错误(null) entry in command string: null chmod 0700，

8,右击run as -->run configurations,配置运行时的输如输出参数，run

9,运行完成后，刷新dfs,查看结果