windows10+eclipse neon+hadoop2.6.4(偽分散式)遠端連線虛擬機器環境搭建
0.需要用到的工具
jdk(我的是1.8)
hadoop-eclipse-plugin-2.6.4.jar(這裡我提供已編譯好的包 下載地址,若是其他版本可自行搜尋或用ant和hadoop原始碼自行編譯)
eclipse(我的版本是neon)
hadoop-2.6.4.tar.gz
hadoop.dll 和 winutil.exe(提供下載:下載地址)
1.將hadoop-2.6.4.tar.gz解壓2.Windows下的環境配置
配置HADOOP_HOME環境變數
新增HADOOP_HOME 路徑為你的hadoop目錄
編輯PATH 新增%HADOOP%\bin
防止專案執行時報錯,將hadoop.dll和winutils.exe(上面有下載連結)拷貝到hadoop中的bin目錄下
然後將hadoop.dll 拷貝到 C:\windows\system32下
3.更改hdfs-site.xml檔案,改成以下內容,若沒有則新增
<property>
<name>dfs.permissions</name>
<value>false</value>
</property>
目的是為了防止windows連線Hadoop伺服器時被拒絕報錯:org.apache.hadoop.security.AccessControlException: Permission denied: 修改後重啟Hadoop
4.將hadoop-eclipse-plugin-2.6.4.jar 放到eclipse的plugins目錄中
5.開啟eclipse,windows》 preference 找到Hadoop Map/Reduce 設定你的hadoop目錄
6.顯示hadoop連線配置介面,windows》show view》other 找到Hadoop Map/Reduce
在下方會顯示hadoop map/reduce 視窗
右鍵點選空白處,選擇New Hadoop Location 彈出此視窗
Location name:隨便填
Host:都填你的虛擬機器ip地址
User name:本地的windows使用者名稱稱(須修改你本地windows賬戶名稱為你的hadoop使用者名稱稱或者 在hadoop叢集下新建一個與windows賬戶名相同的賬戶
7.配置好後點擊 Finish,點選專案管理器上的hadoop伺服器名旁邊的小三角展開目錄,若成功連線則會顯示目錄
8.執行wordcount例項
建立一個map/reduce project,新建專案new》file》other》map/reduce project
建立類 org.apache.hadoop.examples.WordCount
在WordCount.java,寫入以下程式碼
package org.apache.hadoop.examples;
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> [<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);
for (int i = 0; i < otherArgs.length - 1; ++i) {
FileInputFormat.addInputPath(job, new Path(otherArgs[i]));
}
FileOutputFormat.setOutputPath(job,
new Path(otherArgs[otherArgs.length - 1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}
右鍵點選WordCount.java 選擇Run as》Run configuration 選擇Arguments
新增以下內容
hdfs://你的虛擬機器ip:9000/input hdfs://你的虛擬機器ip:9000/output
input是你的輸入目錄 output是你的輸出目錄,可自行更改
之後點選Run,程式會開始執行。
9.執行完成後,右鍵點選專案資源管理器上的hadoop伺服器,點選refresh,即可看到輸出資料夾,part-r-00000 就是輸出結果