本文主要介紹本地Eclipse開發(fā)連接遠(yuǎn)程阿里云Hadoop的環(huán)境搭建
首先需要在遠(yuǎn)程服務(wù)器部署好Hadoop運行環(huán)境
可以參考Hadoop偽分布式環(huán)境搭建
遠(yuǎn)程Hadoop環(huán)境創(chuàng)建好以后,接下來開始本地Eclipse環(huán)境的搭建

一,Eclipse下載和Hadoop插件下載

1,Eclipse官網(wǎng)下載Eclipse

2,接下來解決對應(yīng)版本的Hadoop插件
示例中Hadoop的環(huán)境是2.7.3,這里也需要網(wǎng)上下載hadoop-eclipse-plugin-2.7.3.jar

3,將下載好的插件hadoop-eclipse-plugin-2.7.3.jar放在eclipse/dropins中,然后重啟Eclipse

二,插件配置

1,Eclipse重啟后將會出現(xiàn)紅圈所示的部分,這說明插件加

9B9E2508-5B89-4C3F-AEAF-7ACE3E42AC45.png

2,
選擇File->New->Project->Map/Reduce Project
創(chuàng)建一個WordCount工程

3,打開Eclipse的Preferences界面
選擇Hadoop Map/Reduce選項
把Hadoop的安裝目錄選擇進(jìn)去.
這里可能會有一個疑問, Hadoop是在遠(yuǎn)程阿里云上安裝的,這個目錄怎么選擇?
其實是把遠(yuǎn)程hadoop的運行程序在本地copy一份,然后解壓,選擇的是本地的

5FD251A4-D3B3-46F5-8A9B-BE6D3A42A504.png

4,設(shè)置Hadoop Tool
點擊Window-->Show View -->MapReduce Tools 點擊 Map/ReduceLocation
彈出如下界面,然后進(jìn)

A4DC31C6-B60F-4A0F-95FB-71FB03A0B238.png

設(shè)置成功后,會出現(xiàn)如下界面

CB2244E9-A6F6-430B-A3EA-4AEFB1FB3F0D.png

5,設(shè)置阿里云
1,修改 hadoop/etc/hadoop/hdfs-site.xml

<configuration>
        <property>
                <name>dfs.replication</name>
                <value>1</value>
        </property>

        <property>
                <name>dfs.permissions</name>
                <value>false</value>
        </property>
</configuration>

2,修改hadoop/etc/hadoop/core-site.xml

<configuration>
        <property>
                <name>fs.defaultFS</name>
                <value>hdfs://120.27.4.193:9000</value>
        </property>
</configuration>

三,創(chuàng)建Demo測試

1,新建WordCount工程,添加WordCount.java類

import java.io.IOException;
import java.util.StringTokenizer;
 
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;
import org.apache.hadoop.util.GenericOptionsParser;
 
public class WordCount {
 
  public static class TokenizerMapper 
       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 {
      StringTokenizer itr = new StringTokenizer(value.toString());
      while (itr.hasMoreTokens()) {
        word.set(itr.nextToken());
        context.write(word, one);
      }
    }
  }
 
  public static class IntSumReducer 
       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();
    String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
    if (otherArgs.length != 2) {
      System.err.println("Usage: wordcount <in> <out>");
      System.exit(2);
    }
    Job job = new Job(conf, "word count");
    job.setJarByClass(WordCount.class);
    job.setMapperClass(TokenizerMapper.class);
    job.setCombinerClass(IntSumReducer.class);
    job.setReducerClass(IntSumReducer.class);
    job.setOutputKeyClass(Text.class);
    job.setOutputValueClass(IntWritable.class);
    FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
    FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
    System.exit(job.waitForCompletion(true) ? 0 : 1);
  }
}

2,在工程下面添加一個輸入文件,就是程序的輸入數(shù)據(jù)Input

EFB33C8A-080B-424D-9F4A-985692609A2F.png

3,選中WordCount.java右鍵->Run As -> Run as configure
執(zhí)行輸入文件名字就是剛才的Input文件,和輸出目錄名字Out(自動生成),然后點擊右下角的run運行

8ECF399A-BA49-4FDE-A44D-0129406FD7CE.png

4,運行完畢后,選中WordCount工程,然后Refresh
運行結(jié)果目錄就出來了,里面有結(jié)果文件

9D156AD1-4454-4B6F-8FCF-68137310FA90.png

至此,本地Eclipse開發(fā)連接遠(yuǎn)程阿里云Hadoop結(jié)束