Hadoop2.6.0的Eclipse插件编译和设置

编译Hadoop2.6.0的eclipse插件

下载源码:

git clone https://github.com/winghc/hadoop2x-eclipse-plugin.git

编译源码:

src/contrib/eclipse-plugin
ant jar -Dversion=2.6.0 -Declipse.home=/usr/local/eclipse -Dhadoop.home=/usr/local/hadoop-2.6.0  //需要手动安装的eclipse,通过命令行一键安装的不行

eclipse.home 和 hadoop.home 设置成你自己的环境路径

生成位置:

[jar] Building jar: /home/hunter/hadoop2x-eclipse-plugin/build/contrib/eclipse-plugin/hadoop-eclipse-plugin-2.6.0.jar

安装插件

登录桌面后面要打开eclipse的用户最好是hadoop的管理员,也就是hadoop安装时设置的那个用户,否则会出现拒绝读写权限问题。

复制编译好的jar到eclipse插件目录,重启eclipse

配置 hadoop 安装目录

window ->preference -> hadoop Map/Reduce -> Hadoop installation directory

配置Map/Reduce 视图

window ->Open Perspective -> other->Map/Reduce -> 点击“OK”

windows → show view → other->Map/Reduce Locations-> 点击“OK”

控制台会多出一个“Map/Reduce Locations”的Tab页

在“Map/Reduce Locations” Tab页 点击图标<大象+>或者在空白的地方右键,选择“New Hadoop location…”,弹出对话框“New hadoop location…”,配置如下内容:将ha1改为自己的hadoop用户

Hadoop2.6.0的Eclipse插件编译和设置

注意:MR Master和DFS Master配置必须和mapred-site.xml和core-site.xml等配置文件一致

打开Project Explorer,查看HDFS文件系统。

新建Map/Reduce任务

File->New->project->Map/Reduce Project->Next

编写WordCount类:记得先把服务都起来

import java.io.IOException;
import java.util.*;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.conf.*;
import org.apache.hadoop.io.*;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.util.*;
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.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);
}
}

配置运行时参数:右键-->Run as-->Run Confiugrations

Hadoop2.6.0的Eclipse插件编译和设置

user/ha1/input/hadoop是你上传在hdfs的文件夹(自己创建),里面放要处理的文件。ouput4放输出结果

将程序放在hadoop集群上运行:右键-->Runas -->Run on Hadoop,最终的输出结果会在HDFS相应的文件夹下显示。至此,Ubuntu下hadoop-2.6.0 eclipse插件配置完成。

配置过程中出先的问题:

在eclipse中无法向文件HDFS文件系统写入的问题,这将直接导致eclipse下编写的程序不能在hadoop上运行。

打开conf/hdfs-site.xml,找到dfs.permissions属性修改为false(默认为true)OK了。

<property>

<name>dfs.permissions</name>

<value>false</value>

</property>

改完需要重启HDFS;

最简单的就是刚才说的登录桌面启动eclipse的用户本身就是hadoop的管理员

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